Filed Pursuant to Rule 433 Registration No.: 333-118843 [BANC OF AMERICA SECURITIES LOGO] - -------------------------------------------------------------------------------- The asset-backed securities referred to in these materials, and the asset pools backing them, are subject to modification or revision (including the possibility that one or more classes of securities may be split, combined or eliminated at any time prior to issuance or availability of a final prospectus) and are offered on a "when, as and if issued" basis. You understand that, when you are considering the purchase of these securities, a contract of sale will come into being no sooner than the date on which the relevant class has been priced and we have confirmed the allocation of securities to be made to you; any "indications of interest" expressed by you, and any "soft circles" generated by us, will not create binding contractual obligations for you or us. Because the asset-backed securities are being offered on a "when, as and if issued" basis, any such contract will terminate, by its terms, without any further obligation or liability between us, if the securities themselves, or the particular class to which the contract relates, are not issued. Because the asset-backed securities are subject to modification or revision, any such contract also is conditioned upon the understanding that no material change will occur with respect to the relevant class of securities prior to the closing date. If a material change does occur with respect to such class, our contract will terminate, by its terms, without any further obligation or liability between us (the "Automatic Termination"). If an Automatic Termination occurs, we will provide you with revised offering materials reflecting the material change and give you an opportunity to purchase such class. To indicate your interest in purchasing the class, you must communicate to us your desire to do so within such timeframe as may be designated in connection with your receipt of the revised offering materials. MBS New Issue Term Sheet Banc of America Mortgage 2005-12 Trust Mortgage Pass-Through Certificates, Series 2005-12 $298,847,554 (approximate) Banc of America Mortgage Securities, Inc. Depositor Bank of America, National Association Seller and Servicer [BANK OF AMERICA LOGO] December 21, 2005 - -------------------------------------------------------------------------------- The issuer has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, the issuer, any underwriter or any dealer participating in the offering will arrange to send you the prospectus if you request it by calling toll-free 1-800-294-1322 or you e-mail a request to dg.prospectus_distribution@bofasecurities.com. The securities may not be suitable for all investors. Banc of America Securities LLC and its affiliates may acquire, hold or sell positions in these securities, or in related derivatives, and may have an investment or commercial banking relationship with the issuer. The information contained in these materials may be based on assumptions regarding market conditions and other matters as reflected herein. Banc of America Securities LLC (the "Underwriter") makes no representation regarding the reasonableness of such assumptions or the likelihood that any such assumptions will coincide with actual market conditions or events, and these materials should not be relied upon for such purposes. The Underwriter and its affiliates, officers, directors, partners and employees, including persons involved in the preparation or issuance of these materials, may, from time to time, have long or short positions in, and buy and sell, the securities mentioned herein or derivatives thereof (including options). Information in these materials is current as of the date appearing on the material only. Information in these materials regarding any securities discussed herein supersedes all prior information regarding such securities. These materials are not to be construed as an offer to sell or the solicitation of any offer to buy any security in any jurisdiction where such an offer or solicitation would be illegal. - -------------------------------------------------------------------------------- IRS CIRCULAR 230 NOTICE THIS FREE WRITING PROSPECTUS IS NOT INTENDED OR WRITTEN TO BE USED, AND CANNOT BE USED, FOR THE PURPOSE OF AVOIDING U.S. FEDERAL, STATE OR LOCAL TAX PENALTIES. THIS FREE WRITING PROSPECTUS IS WRITTEN AND PROVIDED BY THE UNDERWRITER IN CONNECTION WITH THE PROMOTION OR MARKETING OF THE TRANSACTIONS OR MATTERS ADDRESSED HEREIN. INVESTORS SHOULD SEEK ADVICE BASED ON THEIR PARTICULAR CIRCUMSTANCES FROM AN INDEPENDENT TAX ADVISOR. - -------------------------------------------------------------------------------- [BANC OF AMERICA SECURITIES LOGO] Banc of America Mortgage Securities, Inc. Mortgage Pass-Through Certificates, 2005-12 $298,847,554 (approximate) - -------------------------------------------------------------------------------- Last Scheduled Pass- WAL (Yrs) Prin Pmt (Mths) Through Class Class Balance (1) (Call/Mat) (2) (Call/Mat) (2) Rate Principal and Interest Type - ----- ----------------- -------------- --------------- ------------- -------------------------------------------------- A-1 $20,445,000 11.16/14.21(6) 37-140/37-360 5.75% Senior, Sequential Pay, Special Retail, Fixed Rate A-2 $81,828,000 3.86/ 3.86 1-131/1-131 (3) Senior, Companion, Floating Rate A-3 $14,232,000 3.86/ 3.86 1-131/1-131 (4) Senior, Companion, Inverse Floating Rate A-4 $132,775,000 3.95/ 3.95 1-96/1-96 5.75% Senior, Planned Amortization, Fixed Rate A-5 $4,104,000 8.33/ 8.33 96-104/96-104 5.75% Senior, Planned Amortization, Fixed Rate A-6 $320,008 11.16/ 14.21 37-140/37-360 None Senior, Sequential Pay, Principal Only A-7 $27,032,000 9.64/11.04 61-140/61-360 5.75% Super Senior, Lockout, Fixed Rate A-8 $3,003,000 9.64/ 11.04 61-140/61-360 5.75% Super Senior Support, Lockout, Fixed Rate A-R $100 Information Not Provided Herein Senior, Sequential Pay, Residual A-PO $7,149,445 5.22/ 5.62 1-140/1-360 None Senior, Ratio Strip, Principal Only $3,526,940 A-IO (Notional) 5.26/ 5.66 NA-NA/NA-NA 5.75% Senior, Fixed Rate, Interest Only B-1 $5,406,000 9.03/10.28 1-140/1-360 5.75% Subordinate, Fixed Rate B-2 $1,652,000 9.03/ 10.28 1-140/1-360 5.75% Subordinate, Fixed Rate B-3 $901,000 9.03/ 10.28 1-140/1-360 5.75% Subordinate, Fixed Rate B-4 $601,000 Information Not Provided Herein Subordinate, Fixed Rate B-5 $451,000 Information Not Provided Herein Subordinate, Fixed Rate B-6 $450,575 Information Not Provided Herein Subordinate, Fixed Rate Expected Expected Credit Ratings Class Enhancement(5) (Fitch\Moody's) - ----- -------------- --------------- A-1 3.15% AAA/Aaa A-2 3.15% AAA/Aaa A-3 3.15% AAA/Aaa A-4 3.15% AAA/Aaa A-5 3.15% AAA/Aaa A-6 3.15% AAA/Aaa A-7 3.15% AAA/Aaa A-8 3.15% AAA/Aa1 A-R 3.15% AAA/None A-PO 3.15% AAA/Aaa A-IO 3.15% AAA/Aaa B-1 1.35% AA/None B-2 0.80% A/None B-3 0.50% BBB/None B-4 0.30% BB/None B-5 0.15% B/None B-6 0.00% NR (1) The Certificate sizes are approximate and are subject to a +/- 5% variance. (2) The Weighted Average Life, Last Scheduled Principal Payment to Call and to Maturity for the Certificates are shown to 300% PSA. (3) During the initial LIBOR Based Interest Accrual Period, interest will accrue on the Class A-2 Certificates at the rate of 5.19% per annum. During each LIBOR Based Interest Accrual Period thereafter, interest will accrue on the Class A-2 Certificates at a per annum rate equal to (i) 0.900% plus (ii) the arithmetic mean of the London interbank offered rate quotations for one-month U.S. dollar deposits ("LIBOR") determined monthly by the Trustee, subject to a minimum rate of 0.900% and a maximum rate of 6.750%. (4) During the initial LIBOR Based Interest Accrual Period, interest will accrue on the Class A-3 Certificates at the rate of 8.96976393% % per annum. During each LIBOR Based Interest Accrual Period thereafter interest will accrue on the Class A-3 Certificates at a per annum rate equal to (i) 33.63545531% minus (ii) the product of 5.74957841 and LIBOR determined monthly as set forth in this Prospectus Supplement, subject to a minimum rate of 0.00% and a maximum rate of 33.63545531%. (5) The credit enhancement sizes are preliminary and subject to change based upon the final pool as of the Cut-off Date and any additional rating agency analysis. (6) The weighted average life of the class of Special Retail Certificates applies to such class as a whole. Because of the special procedures for allocating principal distributions to holders within the class of Special Retail Certificates, the weighted average life of an individual certificate may vary from the weighted average life of the class as a whole. - -------------------------------------------------------------------------------- Preliminary Summary of Terms - -------------------------------------------------------------------------------- Transaction: Banc of America Mortgage 2005-12 Trust Mortgage Pass-Through Certificates, Series 2005-12 Depositor: Banc of America Mortgage Securities, Inc. Underwriter: Banc of America Securities LLC Seller and Servicer: Bank of America, National Association Trustee: Wells Fargo Bank, National Association Insurer of the Special Retail Certificates: Assured Guaranty Corp. Rating Agencies: Moody's Investors Service, Inc. and Fitch Ratings Offered Size: $298,847,554 Expected Closing Date: December 29, 2005 Expected Investor Closing Date: December 30, 2005 Distribution Date: 25th of each month, or the next succeeding business day (First Distribution Date: January 25, 2006) Cut-off Date: December 1, 2005. Determination Date: For any Distribution Date, the 16th day of the month in which the Distribution Date occurs or, if that day is not a business day, the immediately preceding business day Record Date: For any Distribution Date, the close of business on the last business day of the month preceding the month of that Distribution Date. Senior Certificates: Class A-1, A-2, A-3, A-4, A-5, A-6, A-7, A-8, A-PO, A-IO and A-R Certificates. The Class A-R Certificate is not offered hereunder. Subordinate Certificates or Class B Certificates: Class B-1, B-2, B-3, B-4, B-5 and B-6. The Class B-4, B-5 and B-6 Certificates are not offered hereunder. Offered Certificates: Class A-1, A-2, A-3, A-4, A-5, A-6, A-7, A-8, A-PO, A-IO, B-1, B-2 and B-3 Certificates. Floating Rate Certificates: Class A-2 Inverse Floating Rate Certificates: Class A-3 Interest Only Certificates: Class A-IO Principal Only Certificates: Class A-6 and Class A-PO Lockout Certificates: Class A-7 and Class A-8 PAC Certificates: Class A-4 and Class A-5 Companion Certificates: Class A-2 and Class A-3 Super Senior Certificates: Class A-7 Super Senior Support Certificates: Class A-8 Special Retail Certificates: Class A-1 Residual Certificate: Class A-R Day Count: 30/360 Pricing Speed: 300% PSA. "PSA" or the Prepayment Standard Assumption represents an assumed rate of principal prepayment each month relative to the then-outstanding principal balance of a pool of mortgage loans for the life of such mortgage loans. A prepayment assumption of 100% PSA assumes constant prepayment rates of 0.2% per annum of the then-outstanding principal balance of such mortgage loans in the first month of the life of the mortgage loans and an additional 0.2% per annum in each month thereafter until the thirtieth month. Beginning in the thirtieth month and in each month thereafter during the life of the mortgage loans, 100% PSA assumes a constant prepayment rate of 6% per annum each month. Clearing: DTC, Clearstream and Euroclear. Original Certificate Minimum Incremental Denominations: Form Denominations Denominations A-2, A-3, A-4, A-5, A-7 and A-8 Book Entry $1,000 $1 Special Retail Certificates Book Entry $1,000 $1,000 Principal Only Certificates Book Entry $25,000 $1 Interest Only Certificates Book Entry $1,000,000 $1 Subordinate Certificates Book Entry $25,000 $1 SMMEA Eligibility: The Senior Certificates and the Class B-1 Certificates are expected to constitute "mortgage related securities" for purposes of SMMEA. ERISA Eligibility: A fiduciary or other person acting on behalf of any employee benefit plan or arrangement, including an individual retirement account, subject to the Employee Retirement Income Security Act of 1974, as amended ("ERISA"), the Code or any federal, state or local law ("Similar Law") which is similar to ERISA or the Code (collectively, a "Plan") should carefully review with its legal advisors whether the purchase or holding of an Offered Certificate could give rise to a transaction prohibited or not otherwise permissible under ERISA, the Code or Similar Law. The U.S. Department of Labor has extended to Banc of America Securities LLC an administrative exemption (the "Exemption") from certain of the prohibited transaction rules of ERISA and the related excise tax provisions of Section 4975 of the Code with respect to the initial purchase, the holding and the subsequent resale by certain Plans of certificates in pass-through trusts that consist of certain receivables, loans and other obligations that meet the conditions and requirements of the Exemption. The Exemption may cover the acquisition and holding of the Offered Certificates by the Plans to which it applies provided that all conditions of the Exemption other than those within the control of the investors are met. In addition, as of the date hereof, there is no single mortgagor that is the obligor on 5% of the initial balance of the Mortgage Pool. Prospective Plan investors should consult with their legal advisors concerning the impact of ERISA, the Code and Similar Law, the applicability of PTE 83-1 and the Exemption, and the potential consequences in their specific circumstances, prior to making an investment in the Offered Certificates. Moreover, each Plan fiduciary should determine whether under the governing plan instruments and the applicable fiduciary standards of investment prudence and diversification, an investment in the Offered Certificates is appropriate for the Plan, taking into account the overall investment policy of the Plan and the composition of the Plan's investment portfolio. Tax Structure: For federal income tax purposes, an election will be made to treat the Trust as a "real estate mortgage investment conduit" (a "REMIC"). The Offered Certificates (other than the Class A-R Certificate) will constitute "regular interests" in the REMIC and will be treated as debt instruments for federal income tax purposes. The Class A-R Certificate constitutes the sole class of "residual interest" in the REMIC. Optional Termination Date: On any Distribution Date on which the aggregate Stated Principal Balance of the Mortgage Loans is less than 10% of the initial aggregate unpaid principal balance of the Mortgage Loans as of the Cut-off Date, the Servicer may, at its option, subject to certain conditions, purchase the Mortgage Loans, which would effect an early retirement of the Certificates. Reserve Fund and Policy for the Class A-1 Certificates: The Class A-1 Certificates are entitled to the benefit of a reserve fund as protection against certain interest shortfalls arising from the timing of principal payments on the Mortgage Loans up to $10,000. The Class A-1 Certificates also will be entitled to the benefit of an irrevocable financial guaranty insurance policy to be issued by Assured Guaranty Corp. ("Assured Guaranty"). Under the policy, Assured Guaranty will unconditionally and irrevocably guarantee: o the current payment of interest allocated to the Class A-1 Certificates, other than interest shortfalls arising from the timing of principal payments on the Mortgage Loans and interest shortfalls attributable to the Servicemembers Civil Relief Act or comparable state legislation; and o the payment of any losses of principal allocated to the Class A-1 Certificates. The Pooling Agreement: The Certificates will be issued pursuant to a Pooling and Servicing Agreement (the "Pooling Agreement") to be dated the Closing Date, among the Depositor, the Servicer and the Trustee. The Mortgage Pool: The "Mortgage Pool" will consist of fixed rate, conventional, fully-amortizing mortgage loans (the "Mortgage Loans,") secured by first liens on one- to four-family properties. All of the Mortgage Loans were originated or acquired by Bank of America, National Association, which is an affiliate of the Depositor and Banc of America Securities LLC. Compensating Interest: Pursuant to the Pooling Agreement, the aggregate Servicing Fee payable to the Servicer for any month will be reduced (but not below zero) by an amount equal to the lesser of (i) the Prepayment Interest Shortfall for such Distribution Date and (ii) one-twelfth of 0.25% of the aggregate Stated Principal Balance of the Mortgage Loans as of the due date in the month preceding the month of such Distribution Date (such amount, the "Compensating Interest"). The "Prepayment Interest Shortfall" is equal to the difference between (x) 30 days' interest at the mortgage interest rate (less the Servicing Fee Rate) on the amount of each prepayment on the Mortgage Loans minus (y) the amount of interest actually paid by the related mortgagors on the amount of such prepayments during the preceding month. Advances: Subject to the certain limitations, the Servicer will be required pursuant to the Pooling Agreement to advance (any such advance, an "Advance") prior to each remittance date an amount equal to the aggregate of payments of principal and interest (net of the Servicing Fee) which were due on the related due date on the Mortgage Loans and which were delinquent on the related Determination Date. Advances made by the Servicer will be made from its own funds or funds available for future distribution. The obligation to make an Advance with respect to any Mortgage Loan will continue until the ultimate disposition of the REO Property or Mortgaged Property relating to such Mortgage Loan. An "REO Property" is a Mortgaged Property that has been acquired by the Trust through foreclosure or grant of a deed in lieu of foreclosure. Class Balance: The class balance of a class of Certificates at any time will equal its initial class balance less (i) all distributions of principal made to such class, and (ii) losses allocated to such class. Notional Amount: The Notional Amount of the Class A-IO Certificates will be equal to the product of (i) the aggregate of the Stated Principal Balances of the Mortgage Loans with Net Mortgage Interest Rate as of the Cut-off Date greater than or equal to 5.750% as of the due date in the month preceding the month of such Distribution Date and (ii) a fraction, (a) the numerator of which is equal to the weighted average of the Net Mortgage Interest Rates of the these Mortgage Loans (based on the Stated Principal Balances of these Mortgage Loans as of the due date in the month preceding the month of such Distribution Date) minus 5.750% and (b) the denominator of which is equal to 5.750% Net Mortgage Interest Rate: The "Net Mortgage Interest Rate" of a Mortgage Loan is the excess of its mortgage interest rate over the sum of the servicing fee rate (which is 0.25%) and the Trustee fee rate (which is 0.0065%) Reserve Fund: A reserve fund will be established on the Closing Date for the benefit of the Class A-1 Certificates (the "Reserve Fund") by an initial deposit into an account maintained by the Trustee in the amount of approximately $10,000. No additional amounts will be deposited into the Reserve Fund after the initial deposit. The Reserve Fund will be beneficially owned by the Underwriter and will not be an asset of the REMIC. A withdrawal will be made on each Distribution Date from the amount on deposit in the Reserve Fund, to the extent available, to cover any Non-Supported Interest Shortfalls allocated to the Class A-1 Certificates. A withdrawal from the Reserve Fund may only be made, to the extent funds are available therein, to cover any Non-Supported Interest Shortfall allocated to the Class A-1 Certificates and may not be made to cover any Non-Supported Interest Shortfall allocated to any other class. Once the Reserve Fund has been reduced to zero, the Policy will not cover any Non-Supported Interest Shortfalls allocated to Class A-1 Certificates. A "Non-Supported Interest Shortfall" is the amount by which the aggregate of Prepayment Interest Shortfalls for the Mortgage Loans during the calendar month preceding the month of such Distribution Date exceeds the applicable Compensating Interest for such period. The balance of any amount remaining in the Reserve Fund on the Distribution Date on which the class balance of a Class A-1 Certificates is reduced to zero will be distributed to the Underwriter. Neither the Reserve Fund nor the Policy will cover any Net Interest Shortfalls arising as a result of a Relief Act Reduction allocated to the Class A-1 Certificates. With respect to any Distribution Date, the "Net Interest Shortfall" is equal to the sum of (i) the shortfall in interest received with respect to any Mortgage Loan as a result of a Relief Act Reduction and (ii) any Non-Supported Interest Shortfalls. A "Relief Act Reduction" is a reduction in the amount of monthly interest payment on a Mortgage Loan pursuant to the Servicemembers Civil Relief Act or similar state legislation. Distributions in Reduction of the Special Retail Certificates: As to distributions of principal among holders of the Class A-1 Certificates (the "Special Retail Certificates"), Deceased Holders (as defined below) will be entitled to first priority (up to a limit of approximately $100,000, as described below) and beneficial owners other than Deceased Holders ("Living Holders") will be entitled to second priority (up to a limit of approximately $10,000, as described below). Beneficial owners of the class of the Special Retail Certificates will have the right to request that distributions of principal be made with respect to their Special Retail Certificates on each Distribution Date on which distributions of principal are made with respect to that class. All such requested distributions are subject to the priorities described below and to the limitations (i) that they be made only in lots equal to $1,000 of initial class balance and (ii) that aggregate distributions on the class of Special Retail Certificates on a Distribution Date will not exceed the portion of the Senior Principal Distribution Amount allocated to the Class A-1 Certificates on that Distribution Date (plus any amounts available from the Rounding Account, as described below). To the extent that amounts available for distributions of principal on the class of Special Retail Certificates on any Distribution Date exceed the aggregate requests by Deceased Holders and Living Holders of that class for principal distributions applicable to that Distribution Date, those excess amounts will be distributed to the beneficial owners of that class by random lot, as described below. On each Distribution Date, on which amounts are available for distribution of principal on the class of Special Retail Certificates, the aggregate amount allocable to those distributions will be rounded upward, as necessary, to equal an integral multiple of $1,000, except as provided below, in accordance with the priorities and limitations set forth in this discussion. Rounding will be accomplished on the first Distribution Date on which distributions of principal on the class of Special Retail Certificates are made, by withdrawing, from a non-interest bearing account to be established on the Closing Date for the Special Retail Certificates, with a $999.99 deposit by the Underwriter (the "Rounding Account"), the amount of funds, if any, needed to round the amounts otherwise available for distributions to the Special Retail Certificates upward to the next higher integral multiple of $1,000. On each succeeding Distribution Date on which distributions of principal on the class of Special Retail Certificates are to be made, the amounts allocable to the class will be applied first to repay any funds withdrawn from the Rounding Account on the prior Distribution Date, and then the remainder of such allocable amount, if any, will be similarly rounded upward through another withdrawal from the Rounding Account and distributed as principal on that class. This process will continue on succeeding Distribution Dates with respect to the class of Special Retail Certificates until its class balance has been reduced to zero. Thus, the aggregate distribution made in reduction of the class balance of the class of Special Retail Certificates on each Distribution Date may be slightly more or less than would be the case in the absence of such rounding procedures, but such difference will be no more than $999.99 on that Distribution Date. Under no circumstances will the sum of all distributions of principal on the class of Special Retail Certificates through any Distribution Date be less than the sum that would have resulted in the absence of such rounding procedures. A beneficial owner of a Special Retail Certificate who has submitted a request for a principal distribution may not receive a distribution at any particular time after its request, since there can be no assurance that funds will be available for making principal distributions on the class of Special Retail Certificates on any particular Distribution Date. Even if funds are available, those distributions with respect to the Special Retail Certificates owned by any particular beneficial owner may not be made. Also, due to the procedure for mandatory distributions described below, there can be no assurance that on any Distribution Date on which the funds available for distribution of principal on the class of Special Retail Certificates exceed the aggregate amount of distributions requested by beneficial owners of the class, any particular beneficial owner will not receive a principal distribution from such excess funds even if such beneficial owner has not submitted a request for distribution. Thus, the timing of distributions of principal with respect to any particular Special Retail Certificate is highly uncertain, and such distributions may be made earlier or later than the date that may be desired by a beneficial owner. Priority of Requested Distributions Subject to the limitations described herein, including the order of the receipt of the request for distributions as described below under "-- Procedure for Requesting Distributions," beneficial owners of the Special Retail Certificates have the right to request that distributions of principal on their Special Retail Certificates be made. On each Distribution Date on which distributions of principal on the class of Special Retail Certificates are made, priority of payment on that class will be given to beneficial owners for whom principal payment requests are in effect. For the class of Special Retail Certificates, DTC will honor requests in the following order of priority: First, DTC will honor requests submitted on behalf of Deceased Holders in the order of their receipt by DTC, until those requests have been honored in an amount up to $100,000 for each requesting Deceased Holder; and Second, DTC will honor requests submitted on behalf of Living Holders in the order of their receipt by DTC, until those requests have been honored in an amount up to $10,000 for each requesting Living Holder. Thereafter, DTC will honor requests submitted on behalf of each Deceased Holder as provided in step First up to a second $100,000 and requests submitted on behalf of each Living Holder as provided in step Second up to a second $10,000. This sequence of priorities will be repeated until all principal payment requests for the class of Special Retail Certificates have been honored to the extent of amounts available in reduction of that class. In no event will distributions to the class of Special Retail Certificates exceed the amount of principal available for distribution to such class of Special Retail Certificates on such Distribution Date. In no event will the beneficial owner of a Special Retail Certificate receive a distribution of principal in an amount greater than the principal balance of its Special Retail Certificate. If the amount of principal available for payment on the class of Special Retail Certificates on a given Distribution Date is insufficient to honor all requests with respect to such class, such requests will be honored on succeeding Distribution Dates as principal becomes available. A Special Retail Certificate principal payment request submitted on behalf of a Living Holder who later dies will become entitled to the priority of a newly submitted request on behalf of a Deceased Holder. That priority will be effective for each subsequent Distribution Date if DTC has received a certified copy of the death certificate and any additional appropriate evidence of death and any requested tax waivers by the last business day of the preceding calendar month. Procedure for Requesting Distributions A beneficial owner may request that distributions of principal on such beneficial owner's Special Retail Certificates be made on a Distribution Date by delivering a written request therefor to the participant in the DTC system ("Participants") or to an organization that holds through a Participant (an "Indirect Participant") that maintains such beneficial owner's account in the Special Retail Certificates so that the request for such distribution is received on or before the Record Date for such Distribution Date. In the case of a request on behalf of a Deceased Holder, a certified copy of the death certificate and any additional appropriate evidence of death and any tax waivers are required to be forwarded to the Participant under separate cover. Furthermore, such requests of Deceased Holders that are incomplete may not be honored by the Participant and, if not honored, will lose their priority and must be rerequested. The Participant will in turn make the request of DTC (or, in the case of an Indirect Participant, such Indirect Participant must notify the related Participant of such request, and the Participant will make the request of DTC) on DTC's participant terminal system. Upon receipt of such request, DTC will date and time stamp such request and forward such request to the Trustee. DTC may establish such procedures as it deems fair and equitable to establish the order of receipt of requests for such distributions received by it on the same day. None of the Depositor, the Servicer, Assured Guaranty or the Trustee will be liable for any delay by DTC, any Participant or any Indirect Participant in the delivery of requests for distributions. Requests for distributions of principal received by DTC after the Record Date for such Distribution Date and requests for distributions of principal received in a timely manner but not accepted with respect to a given Distribution Date, will be treated as requests for distributions of principal on the next succeeding Distribution Date and each succeeding Distribution Date thereafter until each request is accepted or is withdrawn as described below. Each request for distributions of principal on a Special Retail Certificate submitted by a beneficial owner of a Special Retail Certificate will be held by DTC until such request has been accepted or has been withdrawn in writing, in the manner set forth below. The principal amount covered by such request will continue to bear interest at the related pass-through rate through the last calendar date of the month preceding the month of the Distribution Date. With respect to Special Retail Certificates for which beneficial owners have requested distributions on a particular Distribution Date on which distributions of principal on the class of Special Retail Certificates are being made, DTC will notify the Participants prior to such Distribution Date whether, and the extent to which, such requests for distributions on the Special Retail Certificates have been accepted. Participants and Indirect Participants holding Special Retail Certificates are required to forward such notices to the beneficial owners of such Certificates. Requested distributions on Special Retail Certificates entitled to such distributions will be due and payable on the applicable Distribution Date and will cease to bear interest after the last calendar date of the month preceding the month of such Distribution Date. Any beneficial owner of a Special Retail Certificate that has requested a distribution may withdraw such request by so notifying in writing the Participant or Indirect Participant that maintains such beneficial owner's account. The Participant will make the request of DTC on DTC's participant terminal system. In the event that such account is maintained by an Indirect Participant, such Indirect Participant must notify the related Participant, which in turn must make the request of DTC on DTC's participant terminal system. If such notice of withdrawal of a request for distribution has not been received by the DTC on or before the Record Date for the Distribution Date, the previously made request for distribution will be irrevocable with respect to the making of distributions of principal on the class of Special Retail Certificates on the applicable Distribution Date. Mandatory Distributions of Principal on the Special Retail Certificates If the amount available for principal distributions on the class of Special Retail Certificates on a Distribution Date exceeds the aggregate amount of distribution requests for that class which have been received by DTC on or before the applicable Record Date, additional Special Retail Certificates in lots equal to $1,000 will be selected to receive principal distributions in accordance with the then-applicable established random lot procedures of DTC, and the procedures of the Participants and Indirect Participants, which may or may not be by random lot. Investors in the Special Retail Certificates should ask Participants or Indirect Participants which allocation procedures they use. Participants and Indirect Participants holding Special Retail Certificates selected for mandatory distributions of principal are required to provide notice of such mandatory distributions to the affected beneficial owners. Deceased Holders A "Deceased Holder" is a beneficial owner of a Special Retail Certificate who was living at the time such interest was acquired and whose executor or other authorized representative causes to be furnished to the Participant a certified copy of the death certificate and any additional evidence of death satisfactory to the Participant and any tax waivers requested by the Participant. Special Retail Certificates beneficially owned by tenants by the entirety, joint tenants or tenants in common will be considered to be beneficially owned by a single owner. The death of a tenant by the entirety, joint tenant or tenant in common will be deemed to be the death of the beneficial owner, and the Special Retail Certificates so owned will be eligible for priority with respect to distributions of principal, subject to the limitations described herein. Special Retail Certificates beneficially owned by a trust will be considered to be beneficially owned by each beneficiary of the trust to the extent of such beneficiary's interest therein, but in no event will a trust's beneficiaries collectively be deemed to be beneficial owners of a number of Special Retail Certificates greater than the number of Special Retail Certificates of which the trust is the owner. The death of the beneficiary of a trust will be deemed to be the death of a beneficial owner of the Special Retail Certificates beneficially owned by the trust to the extent of that beneficiary's interest in the trust. The death of an individual who was a tenant by the entirety, joint tenant or tenant in common in a tenancy that is the beneficiary of a trust will be deemed to be the death of the beneficiary of the trust. The death of a person who, during his or her lifetime, was entitled to substantially all of the beneficial ownership interest in a Special Retail Certificate will be deemed to be the death of the beneficial owner of the Special Retail Certificate regardless of the registration of the ownership, if the beneficial ownership interest can be established to the satisfaction of the Participant. Beneficial interests will be deemed to exist in typical cases of street name or nominee ownership, ownership by a trustee, ownership under the Uniform Gift to Minors Act and community property or other joint ownership arrangements between a husband and wife. Beneficial interests shall include the power to sell, transfer, or otherwise dispose of a Special Retail Certificate and the right to receive the proceeds therefrom, as well as interest payments and distributions in reduction of principal balance with respect thereto. As used in this Prospectus Supplement, a request for a distribution of principal of a Special Retail Certificate by a Deceased Holder shall mean a request by the personal representative, surviving tenant by the entirety, surviving joint tenant or surviving tenant in common of such Deceased Holder. Pro Rata Distributions On each Distribution Date, if Assured Guaranty fails to pay an Insured Amount in respect of principal, distributions of principal on the class of Special Retail Certificates will be made pro rata among the holders of such class of Special Retail Certificates and will not be rounded up to an integral multiple of $1,000 or made in integral multiples of $1,000 nor will distributions be made pursuant to requested distributions or mandatory random lot distributions. If pro rata distributions cannot be made through the facilities of DTC, the Special Retail Certificates will be withdrawn from the facilities of DTC and Definitive Certificates will be issued to the beneficial owners of those Certificates. The Financial Guaranty Insurance Policy: The following summary of terms of the financial guaranty insurance policy to be issued by Assured Guaranty Corp. ("Assured Guaranty") does not purport to be complete and is qualified in its entirety by reference to the Policy referred to below. Assured Guaranty has made a commitment, subject to the satisfaction of certain conditions, to issue a financial guaranty insurance policy (the "Policy") relating to the Banc of America Mortgage Securities, Inc. Mortgage Pass-Through Certificates, Series 2005-12, Class A-1 Certificates (the "Insured Certificates"), effective as of the date of issuance of the Insured Certificates. Under the terms of the Policy, Assured Guaranty will unconditionally and irrevocably guarantee to pay each and every Insured Amount (as defined below) that shall become due for payment but shall be unpaid by reason of Nonpayment (as defined below). The Policy is non-cancelable for any reason. Principal payable by Assured Guaranty under the Policy in respect of the Insured Certificates will in no event exceed the class balance of the Insured Certificates as of the date of issuance, which is expected to be $20,445,000. Assured Guaranty will pay each Insured Amount that constitutes a Deficiency Amount to the Trustee, as beneficiary of the Policy on behalf of the holders of the Insured Certificates, on the later of (i) the Distribution Date on which such Deficiency Amount becomes due for payment or (ii) the third business day following the day on which Assured Guaranty receives notice of claim therefor in accordance with the terms of the Policy. Assured Guaranty will pay each Insured Amount that constitutes a Preference Amount when due to be paid by or on behalf of the holders of the Insured Certificates pursuant to an applicable court order, but in any event no earlier than the fourth business day following receipt by Assured Guaranty of the documentation required by Assured Guaranty in accordance with the terms of the Policy. The terms below are summary descriptions. Reference should be made to the Policy for the actual definition of each term defined below. "Deficiency Amount" means, with respect to the Insured Certificates and any Distribution Date, the amount (if any) equal to (1) the sum of (a) any shortfall in amounts available in the certificate account to pay interest for the related Interest Accrual Period on the class balance of the Insured Certificates at the then applicable pass-through rate for such Distribution Date and (b) the amount of the principal portion of any Realized Losses allocated to the Insured Certificates on such Distribution Date and (2) on the Distribution Date in January 2036 or, with the consent of Assured Guaranty, upon the earlier of the termination of the Trust pursuant to the terms of the Pooling Agreement, the class balance of the Insured Certificates after giving effect to any distributions on such Distribution Date and, in the case of each of clauses (1) and (2), net of any Prepayment Interest Shortfalls or Relief Act Reductions allocated to the Insured Certificates, or any shortfall attributable to the liability of the Trust, the REMIC, the Trustee for withholding or other taxes, including interest and penalties in respect of such liabilities allocated to the Insured Certificates on such Distribution Date; provided, however, that "Deficiency Amount" shall not include any additional amounts owing by the Trust as a result of the failure by the Trustee to pay such amount when due and payable, including, without limitation, any such additional amounts as may be attributable to penalties or default interest rates, amounts in respect of indemnification, or any other additional amounts payable by reason of such a default. "Insured Amount" means, with respect to any Distribution Date, the sum of any Deficiency Amount for such Distribution Date and any Preference Amount. "Insured Payment" means, with respect to any Distribution Date, the aggregate amount paid by Assured Guaranty to the Trustee in respect of (i) the Deficiency Amount for such Distribution Date and (ii) Preference Amounts for any given Business Day. "Nonpayment" means, with respect to any Distribution Date, an Insured Amount is due for payment but the funds, if any, remitted to the Trustee pursuant to the Pooling Agreement are insufficient for payment in full of such Insured Amount. "Preference Amount" means any payment of principal or interest previously distributed by or on behalf of the Trust to a holder of Insured Certificates, which would have been covered under the Policy as a Deficiency Amount if there had been a shortfall in funds available to make such a payment on the required Distribution Date for such payment, which has been deemed a preferential transfer and has been recovered from such holder pursuant to the United States Bankruptcy Code in accordance with a final nonappealable order of a court or other body exercising jurisdiction in an insolvency proceeding by or against the Trust. Assured Guaranty shall be subrogated to the rights of the holders of the Insured Certificates to receive distributions in respect of the Insured Certificates to the extent of any payment by Assured Guaranty under the Policy. The Policy is not covered by the property/casualty insurance fund specified in Article 76 of the New York Insurance Law. Capitalized terms used in the Policy and not otherwise defined in the Policy shall have the meanings set forth in the Pooling Agreement as of the date of execution of the Policy, without giving effect to any subsequent amendment to or modification of the Pooling Agreement unless such amendment or modification has been approved in writing by Assured Guaranty. The Certificate Insurer: Assured Guaranty is a Maryland-domiciled insurance company regulated by the Maryland Insurance Administration and licensed to conduct financial guaranty insurance business in forty-seven states, the District of Columbia and Puerto Rico. Assured Guaranty commenced operations in 1988. Assured Guaranty is a wholly owned, indirect subsidiary of Assured Guaranty Ltd. ("AGL"), a Bermuda-based holding company whose shares are publicly held and are listed on the New York Stock Exchange under the symbol "AGO." AGL, through its operating subsidiaries, provides credit enhancement products to the public finance, structured finance and mortgage markets. Neither AGL nor any of its shareholders is obligated to pay any debts of Assured Guaranty or any claims under any insurance policy issued by Assured Guaranty. Assured Guaranty is subject to insurance laws and regulations in Maryland and in New York (and in other jurisdictions in which it is licensed) that, among other things, (i) limit Assured Guaranty's business to financial guaranty insurance and related lines, (ii) prescribe minimum solvency requirements, including capital and surplus requirements, (iii) limit classes and concentrations of investments, (iv) regulate the amount of both the aggregate and individual risks that may be insured, (v) limit the payment of dividends by Assured Guaranty, (vi) require the maintenance of contingency reserves and (vii) govern changes in control and transactions among affiliates. Certain state laws to which Assured Guaranty is subject also require the approval of policy rates and forms. Assured Guaranty's financial strength is rated "AAA" by Standard & Poor's, a division of The McGraw-Hill Companies, Inc., "Aa1" by Moody's Investors Service, Inc. and "AAA" by Fitch Inc. Each rating of Assured Guaranty should be evaluated independently. An explanation of the significance of the above ratings may be obtained from the applicable rating agency. The above ratings are not recommendations to buy, sell or hold any security, and such ratings are subject to revision or withdrawal at any time by the rating agencies. Any downward revision or withdrawal of any of the above ratings may have an adverse effect on the market price of any security guaranteed by Assured Guaranty. Assured Guaranty does not guaranty the market price of the securities it guarantees, nor does it guaranty that the ratings on such securities will not be revised or withdrawn. Capitalization of Assured Guaranty Corp. The following table sets forth the capitalization of Assured Guaranty as of December 31, 2003 and December 2004 and as of September 30, 2005 (unaudited), on the basis of accounting principles generally accepted in the United States of America ("GAAP"): Capitalization of Assured Guaranty Corp. December 31, 2003 December 31, 2004 September 30, 2005 (in millions) (in millions) (in millions) ----------------- ----------------- ------------------ Unearned Premiums $389 $369 $197 Other Liabilities 236 280 167 Shareholder's Equity: Common Stock 15 15 15 Additional Paid-in Capital 351 386 363 Unrealized Gain on Bonds, Net of Tax 45 43 32 Retained Earnings 465 563 617 Total Shareholder's Equity $876 $1,007 $1,027 ----------------- ----------------- ------------------ Total Liabilities and Shareholder's Equity $1,501 $1,656 $1,391 The following documents are hereby incorporated by reference into this Free Writing Prospectus and shall be deemed to be a part hereof: o The consolidated balance sheets of Assured Guaranty as of December 31, 2004 and December 31, 2003 and the related consolidated statements of operations and comprehensive income, of shareholder's equity and of cash flows for each of the three years in the period ended December 31, 2004, prepared in accordance with GAAP, included as Exhibit 99.1 to the Annual Report on Form 10-K of AGL for the fiscal year ended December 31, 2004 (which was filed with the Securities and Exchange Commission (the "SEC") on March 22, 2005); o The unaudited consolidated balance sheet and statement of shareholder's equity of Assured Guaranty as of and for the period ended March 31, 2005, respectively, and the related consolidated statements of operations and comprehensive income and cash flows for the three months ended March 31, 2005 and March 31, 2004, prepared in accordance with GAAP, included as Exhibit 99.1 to the Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2005 (which was filed by AGL with the SEC on May 12, 2005); o The unaudited consolidated balance sheet and statement of shareholder's equity of Assured Guaranty as of and for the period ended June 30, 2005, respectively, the related consolidated statements of operations and comprehensive income for the three and six months ended June 30, 2005 and June 30, 2004, and the statements of cash flows for the six months ended June 30, 2005 and June 30, 2004, prepared in accordance with GAAP, included as Exhibit 99.1 to the Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2005 (which was filed by AGL with the SEC on August 15, 2005); o The unaudited consolidated balance sheet and statement of shareholder's equity of Assured Guaranty as of and for the period ended September 30, 2005, respectively, the related consolidated statements of operations and comprehensive income for the three and nine months ended September 30, 2005 and September 30, 2004, and the statements of cash flows for the nine months ended September 30, 2005 and September 30, 2004, prepared in accordance with GAAP, included as Exhibit 99.1 to the Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2005 (which was filed by AGL with the SEC on November 7, 2005); and o The Current Reports on Form 8-K filed by AGL with the SEC on April 12, 2005, April 20, 2005, May 10, 2005, May 18, 2005, June 24, 2005, August 5, 2005, December 12, 2005 and December 21, 2005 as they relate to Assured Guaranty. Any statement contained in a document incorporated herein by reference or contained in this Free Writing Prospectus under the heading "The Certificate Insurer" shall be modified or superseded for the purposes of this Free Writing Prospectus to the extent that a statement contained herein or in any subsequently filed document which is incorporated by reference herein also modifies or supersedes such statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Free Writing Prospectus. All consolidated financial statements of Assured Guaranty included in documents filed by AGL with the SEC pursuant to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, subsequent to the date of this Free Writing Prospectus and prior to the termination of the offering of the Insured Certificates shall be deemed to be incorporated by reference into this Free Writing Prospectus and to be a part hereof from the respective dates of filing such consolidated financial statements. The Maryland Insurance Administration recognizes only statutory accounting practices for determining and reporting the financial condition and results of operations of an insurance company, for determining its solvency under the Maryland Insurance Code, and for determining whether its financial condition warrants the payment of a dividend to its stockholders. No consideration is given by the Maryland Insurance Administration to financial statements prepared in accordance with GAAP in making such determinations. Copies of the consolidated financial statements of Assured Guaranty incorporated by reference herein and of the statutory financial statements filed by Assured Guaranty with the Maryland Insurance Administration are available upon request by contacting Assured Guaranty at 1325 Avenue of the Americas, New York, New York 10019 or by calling Assured Guaranty at (212) 974-0100. Assured Guaranty makes no representation regarding the Certificates or the advisability of investing in the Insured Certificates. In addition, Assured Guaranty makes no representation regarding, nor does it accept any responsibility for the accuracy or completeness of this Free Writing Prospectus or any information or disclosure contained herein, or omitted herefrom, other than with respect to the accuracy of the information regarding the Policy and Assured Guaranty supplied by Assured Guaranty and presented under the headings "The Financial Guaranty Insurance Policy" and "The Certificate Insurer" in this Free Writing Prospectus. Stated Principal Balance: The Stated Principal Balance means, as to any Mortgage Loan and due date, the unpaid principal balance of such Mortgage Loan as of such due date, as specified in the amortization schedule at the time relating thereto (before any adjustment to such amortization schedule by reason of any moratorium or similar waiver or grace period), after giving effect to any previous partial principal prepayments and Liquidation Proceeds (net of unreimbursed expenses and unreimbursed Advances) allocable to principal received and to the payment of principal due on such due date and irrespective of any delinquency in payment by the related mortgagor and after giving effect to any deficient valuation by a court in connection with a bankruptcy . Pool Principal Balance (Non-PO Portion): The Pool Principal Balance (Non-PO Portion) for any Distribution Date equals the sum of the product, for each Mortgage Loan, of the Non-PO Percentage of such Mortgage Loan multiplied by its Stated Principal Balance on the due date in the month preceding the month of such Distribution Date. Pool Principal Balance: The Pool Principal Balance with respect to any Distribution Date equals the aggregate Stated Principal Balances of the Mortgage Loans outstanding on the due date in the month preceding the month of such Distribution Date. Non-PO Principal Amount: The "Non-PO Principal Amount" for any Distribution Date will equal the sum of the applicable Non-PO Percentage of: (a) all monthly payments of principal due on each Mortgage Loan on the related due date; (b) the principal portion of the purchase price (net of unreimbursed Advances and other amounts as to which the Servicer is entitled to be reimbursed pursuant to the Pooling Agreement) of each Mortgage Loan that was repurchased by the Depositor pursuant to the Pooling Agreement during the calendar month preceding the month of that Distribution Date; (c) amounts received with respect to such Distribution Date as a substitution adjustment amount (net of unreimbursed Advances and other amounts as to which the Servicer is entitled to be reimbursed pursuant to the Pooling Agreement) received during the calendar month preceding the month of that Distribution Date; (d) any Liquidation Proceeds (net of unreimbursed expenses and unreimbursed Advances, if any) allocable to recoveries of principal of the Mortgage Loans that have not yet been liquidated received during the calendar month preceding the month of that Distribution Date; (e) with respect to each Mortgage Loan that was liquidated during the calendar month preceding the month of that Distribution Date, the amount of the Liquidation Proceeds (other than any profits retained by the Servicer in connection with the foreclosure and net of unreimbursed expenses and unreimbursed Advances, if any) allocable to principal received with respect to that Mortgage Loan; and (f) all partial and full principal prepayments on the Mortgage Loans by mortgagors received during the calendar month preceding the month of that Distribution Date. Senior Principal Distribution Amount: The Senior Principal Distribution Amount for any Distribution Date will equal the sum of (i) the Senior Percentage of the applicable Non-PO Percentage of all amounts described in clauses (a) through (d) of the definition of "Non-PO Principal Amount" for such Distribution Date and (ii) the Senior Prepayment Percentage of the applicable Non-PO Percentage of all amounts described in clauses (e) and (f) of the definition of "Non-PO Principal Amount" for such Distribution Date subject to certain reductions due to losses. Subordinate Principal Distribution Amount: The Subordinate Principal Distribution Amount for any Distribution Date will equal the sum of (i) the Subordinate Percentage for the applicable Non-PO Percentage of all amounts described in clauses (a) through (d) of the definition of "Non-PO Principal Amount" for such Distribution Date and (ii) the Subordinate Prepayment Percentage of the applicable Non-PO Percentage all amounts described in clauses (e) and (f) of the definition of "Non-PO Principal Amount" for such Distribution Date. Senior Percentage: The Senior Percentage on any Distribution Date will equal (i) the aggregate class balance of the Senior Certificates (but not the Class A-PO Certificates) immediately prior to such date, divided by (ii) the Pool Principal Balance (Non-PO Portion) for such date. Subordinate Percentage: The Subordinate Percentage for any Distribution Date will equal 100% minus the Senior Percentage for such date. Non-PO Percentage: The "Non-PO Percentage" with respect to any Mortgage Loan with a Net Mortgage Interest Rate as of the Cut-off Date less than 5.750% (each such Mortgage Loan, a "Discount Mortgage Loan") will be equal to the Net Mortgage Interest Rate as of the Cut-off Date divided by 5.750%. The Non-PO Percentage with respect to any Mortgage Loan with a Net Mortgage Interest Rate as of the Cut-off Date equal to or greater than 5.750 will be 100%. The "PO Percentage" for any Discount Mortgage Loan will be equal to 100% minus the Non-PO Percentage for such Mortgage Loan. Premium Distribution Amount: On each Distribution Date, from and to the extent of the Pool Distribution Amount, Assured Guaranty will be entitled to receive a premium (the "Premium Distribution Amount") with respect to the Class A-1 Certificates. The Premium Distribution Amount will be equal to the sum of (i) the product of one-twelfth of 0.09% and the class balance of the Class A-1 Certificates and (ii) the sum of the amounts, if any, by which the amount described in clause (i) above on each prior Distribution Date exceeded the amount actually distributed in respect of the premium from the Pool Distribution Amount on such prior Distribution Dates and not subsequently distributed. No further amounts will be payable to Assured Guaranty once the Class A-1 Certificates are no longer outstanding. Priority Amount: For any Distribution Date will equal the lesser of (i) the sum of the class balances of the Class A-7 and Class A-8 Certificates and (ii) the product of (a) the Shift Percentage, (b) the Priority Percentage and (c) the Non-PO Principal Amount. Priority Percentage: For any Distribution Date will equal (i) the sum of the class balances of the Class A-7 and Class A-8 Certificates divided by (ii) the Pool Principal Balance (Non-PO Portion) immediately prior to such date. Shift Percentage: For the following Distribution Dates, will be as follows: Distribution Date Shift Percentage January 2006 through December 2010 0% January 2011 through December 2011 30% January 2012 through December 2012 40% January 2013 through December 2013 60% January 2014 through December 2014 80% January 2015 and thereafter 100% Principal Distributions: The Senior Principal Distribution Amount will generally be allocated sequentially as follows: (i) To the Class A-R Certificate, until its class balance has been reduced to zero; (ii) Concurrently, to the Class A-7 and Class A-8 Certificates, pro rata, up to the Priority Amount for such Distribution Date, until their class balances have been reduced to zero; (iii) On or before December 2008, pay sequentially as follows: 1. to the Class A-4 and Class A-5 Certificates, in that order, up to the PAC Principal Amount for such Distribution Date; 2. Concurrently to the Class A-2 and Class A-3 Certificates, pro rata, until their class balances have been reduced to zero; 3. Sequentially to the Class A-4 and Class A-5 Certificates, in that order, until their class balances have been reduced to zero; 4. Concurrently to the Class A-1 and Class A-6 Certificates, pro rata, until their class balances have been reduced to zero; (iv) After December 2008, pay sequentially as follows: 1. $20,765.01 concurrently to the Class A-1 and Class A-6 Certificates, pro rata, until their class balances have been reduced to zero; 2. Sequentially to the Class A-4 and Class A-5 Certificates, in that order, up to the PAC Principal Amount for such Distribution Date; 3. Concurrently to the Class A-2 and Class A-3 Certificates, pro rata, until their class balances have been reduced to zero; 4. Sequentially to the Class A-4 and Class A-5 Certificates, in that order, until their class balances have been reduced to zero; 5. Concurrently to the Class A-1 and Class A-6 Certificates, pro rata, until their class balances have been reduced to zero; (v) Concurrently, to the Class A-7 and Class A-8 Certificates, pro rata, until their class balances have been reduced to zero. Subordinate Prepayment Percentage: The Subordinate Prepayment Percentage for any Distribution Date will equal 100% minus the Senior Prepayment Percentage for such date. Senior Prepayment Percentage: For the following Distribution Dates, will be as follows: Distribution Date Senior Prepayment Percentage January 2006 through December 2010 100%; January 2011 through the applicable Senior Percentage plus, 70% of the December 2011 applicable Subordinate Percentage; January 2012 through the applicable Senior Percentage plus, 60% of the December 2012 applicable Subordinate Percentage; January 2013 through the applicable Senior Percentage plus, 40% of the December 2013 applicable Subordinate Percentage; January 2014 through the applicable Senior Percentage plus, 20% of the December 2014 applicable Subordinate Percentage; January 2015 and thereafter the applicable Senior Percentage; provided, however, if on any Distribution Date the Senior Percentage exceeds the initial Senior Percentage, then the Senior Prepayment Percentage for such Distribution Date will equal 100%. No decrease in the Senior Prepayment Percentage will occur if the following occurs as of any Distribution Date as to which any such decrease applied : (i) the outstanding principal balance of all Mortgage Loans (including, for this purpose, any Mortgage Loans in foreclosure, any REO Property and any Mortgage Loan for which the mortgagor has filed for bankruptcy after the Closing Date) delinquent 60 days or more (averaged over the preceding six-month period), as a percentage of the aggregate class balance of the Class B Certificates, is equal to or greater than 50%, or (ii) cumulative Realized Losses with respect to the Mortgage Loans exceed the percentage of the aggregate balance of the Class B Certificates as of the Closing Date (the "Original Subordinate Principal Balance") indicated below: % of Original Subordinate Distribution Date Occurring Principal Balance ---------------------------------- ------------------------- January 2011 through December 2011 30% January 2012 through December 2012 35% January 2013 through December 2013 40% January 2014 through December 2014 45% January 2015 and thereafter 50% Allocation of Losses: On each Distribution Date, the applicable PO Percentage of any Realized Loss on a Discount Mortgage Loan will be allocated to the Class A-PO Certificates. Such allocation will be effected on each Distribution Date by reducing the class balance of the Class A-PO Certificates, if and to the extent that such class balance (after taking into account the amount of all distributions to be made on such Distribution Date) exceeds the related Adjusted Pool Amount (PO Portion) for such Distribution Date. The amount of any such Realized Loss allocated to the Class A-PO Certificates will be treated as a "Class PO Deferred Amount." To the extent funds are available on such Distribution Date or on any future Distribution Date from amounts that would otherwise be allocable to the Subordinate Principal Distribution Amount, the Class PO Deferred Amounts for the Class A-PO Certificates will be paid on the Class A-PO Certificates prior to distributions of principal on the Class B Certificates. Payments of the Class PO Deferred Amounts will be made from the principal payable to the Subordinate Certificates beginning with the principal payable to the class of Subordinate Certificates with the highest numerical class designation. Any distribution in respect of unpaid Class PO Deferred Amounts for the Class A-PO Certificates will not further reduce the class balance of such Class A-PO Certificates The Class PO Deferred Amounts will not bear interest. The class balance of the class of Class B Certificates then outstanding with the highest numerical class designation will be reduced by the amount of any payments in respect of Class PO Deferred Amounts for the Class A-PO Certificates. Any excess of these Class PO Deferred Amounts over the class balance of that class will be allocated to the next most subordinate class of Class B Certificates to reduce its class balance and so on, as necessary. On each Distribution Date, the applicable Non-PO Percentage of any Realized Loss will be allocated first to the Class B Certificates in the reverse order of their numerical class designations (beginning with the class of Class B Certificates then outstanding with the highest numerical class designation), in each case until the class balance of such class of Certificates has been reduced to zero, and then to the Senior Certificates (but not the Class A-PO Certificates) pro rata based on their respective class balances. Such allocation will be effected on each such Distribution Date by reducing the class balance of the class of Class B Certificates then outstanding with the highest numerical class designation if and to the extent that the aggregate of the class balances of all classes of Senior Certificates (but not the Class A-PO Certificates) and the Class B Certificates (after taking into account the amount of all distributions to be made on such Distribution Date) exceeds the Adjusted Pool Amount (Non-PO Portion) for such Distribution Date. In general, a "Realized Loss" means, (a) with respect to a Mortgage Loan that has been liquidated, the amount by which the remaining unpaid principal balance of the Mortgage Loan exceeds the amount of proceeds from the liquidation applied to the principal balance of the related Mortgage Loan and (b) a losses due to the bankruptcy of the mortgagor. After the date on which the aggregate class balance of the Subordinate Certificates has been reduced to zero, on each Distribution Date, the aggregate of the class balances of all classes of Senior Certificates (but not the Class A-PO Certificates) then outstanding will be reduced if and to the extent that such aggregate balance (after taking into account the amount of all distributions to be made on such Distribution Date) exceeds the Adjusted Pool Amount (Non-PO Portion) for such Distribution Date. The amount of any such reduction will be allocated among the Senior Certificates (but not the Class A-PO Certificates) pro rata based on their respective class balances. After the senior credit support depletion date, the class balance of the Class A-8 Certificates will be reduced not only by the principal portion of Realized Losses allocated to such class, but also by the portion allocated to the Class A-7 Certificates. Adjusted Pool Amount: The Adjusted Pool Amount will equal the aggregate unpaid principal balance of the Mortgage Loans as of the Cut-off Date minus the sum of (i) all amounts in respect of principal received in respect of the Mortgage Loans (including amounts received as Advances, principal prepayments and Liquidation Proceeds (net of unreimbursed expenses and unreimbursed advances) in respect of principal) and distributed on the Certificates on such Distribution Date and all prior Distribution Dates and (ii) the principal portion of all Realized Losses (other than debt service reductions) incurred on the Mortgage Loans from the Cut-off Date through the end of the month preceding such Distribution Date. Adjusted Pool Amount (PO Portion) The Adjusted Pool Amount (PO Portion) will equal the sum as to each Mortgage Loan outstanding as of the Cut-off : Date of the product of (A) the PO Percentage for such Mortgage Loan and (B) the principal balance of such Mortgage Loan as of the Cut-off Date less the sum of (i) all amounts in respect of principal received in respect of such Mortgage Loan (including amounts received as Advances, principal prepayments and Liquidation Proceeds (net of unreimbursed expenses and unreimbursed advances) in respect of principal) and distributed on the Certificates on such Distribution Date and all prior Distribution Dates and (ii) the principal portion of any Realized Loss (other than a debt service reduction) incurred on such Mortgage Loan from the Cut-off Date through the end of the month preceding the month in which such Distribution Date occurs. Adjusted Pool Amount (Non-PO Portion): The Adjusted Pool Amount (Non-PO Portion) will equal the difference between the Adjusted Pool Amount and the Adjusted Pool Amount (PO Portion). Interest Accrual: Interest will accrue on the Certificates (other than the Class A-2 and Class A-3 Certificates) during each one-month period ending on the last day of the month preceding the month in which each Distribution Date occurs (each, a "Regular Interest Accrual Period"). The initial Regular Interest Accrual Period will be deemed to have commenced on December 1, 2005. Interest will accrue on the Class A-2 and Class A-3 Certificates from the previous Distribution Date, or in the case of the first Distribution Date, from the Closing Date, through and including the day prior to the current Distribution Date (each, a "LIBOR Based Interest Accrual Period" and together with the Regular Interest Accrual Period, an "Interest Accrual Period"). Planned Amortization Certificates and Companions: The balances of the Class A-4 and Class A-5 Certificates (the "PAC Group") will be reduced to the applicable balances indicated in a predetermined amortization schedule, attached as AppendixA, for each Distribution Date if prepayments on the Mortgage Loans occur at a constant rate between 125% and 350% PSA. It is highly unlikely, however, that the underlying Mortgage Loans will prepay at a constant rate until maturity or that all the underlying Mortgage Loans will prepay at the same rate or that they will have the characteristics assumed. Therefore, there can be no assurance that the balances of the PAC Group after the payment of principal on any Distribution Date will be equal to the balances for such Distribution Date specified in the amortization table attached as Appendix A. The weighted average lives of the PAC Group will vary under different prepayment scenarios. If principal prepayments on the underlying mortgage loans occur at a constant rate that is slower than the lower PAC band, the amount available to make principal payments to the PAC Group may be insufficient to reduce the PAC Group's balances to their planned balances for such Distribution Date. The weighted average lives of the PAC Certificates may therefore be extended. If such principal prepayments on the underlying Mortgage Loans occur at a constant rate that is faster than the upper PAC band, the weighted average lives of the PAC Certificates may be shortened. Because all amounts available for principal payments on any Distribution Date will be distributed to holders on such Distribution Date, the ability to distribute any PAC Principal Amount on any Distribution Date will not be enhanced by the averaging of high and low principal prepayment rates on the underlying Mortgage Loans over several Distribution Dates, as might be the case if any principal payments were held for future applications and not distributed monthly. The extent to which the planned balances and targeted balances are achieved and the sensitivity of any PAC Group to principal prepayments on the underlying Mortgage Loans will depend in part on the period of time during which the class or classes which support the PAC Group remain outstanding. Any Companion Certificates will support the PAC Group. On each Distribution Date, after any PAC Group has received its PAC Principal Amount for such Distribution Date, no further principal payments will be made to the PAC Group until the class balances of the class or classes supporting any PAC Group have been reduced to zero. This support is intended to decrease the likelihood that the balance of the PAC Group will be reduced below its respective planned balance or targeted balance on a given Distribution Date. Once the applicable class or classes that provide support to the PAC Group are no longer outstanding, any PAC Certificates of any PAC Groups will become more sensitive to the rate of prepayments on the underlying Mortgage Loans, as such classes will receive principal payments that otherwise would have been distributable to the class or classes which supported them. - -------------------------------------------------------------------------------- Preliminary Credit Support - -------------------------------------------------------------------------------- The Subordinate Certificates provide credit support for the Senior Certificates. Additional credit enhancement is provided by the allocation of the applicable Non-PO Percentages of all principal prepayments on the Mortgage Loans to the Certificates , subject to certain exceptions, for the first five years and the disproportionately greater allocation of prepayments to the Senior Certificates over the following four years. The disproportionate allocation of prepayments will accelerate the amortization of the Senior Certificates relative to the amortization of the Subordinate Certificates. As a result, the credit support percentage for the Senior Certificates should be maintained and may be increased during the first nine years. Subordination of Certificates | ^ | Senior | | Credit Support [3.15%] | | | | Class B-1 | | Credit Support [1.35%] | | | Priority of | Class B-2 | Order of Payment | Credit Support [0.80%] | Loss | | Allocation | Class B-3 | | Credit Support [0.50%] | | | | Class B-4 | | Credit Support [0.30%] | | | | Class B-5 | | Credit Support [0.15%] | | | | Class B-6 | v Credit Support [0.00%] | - -------------------------------------------------------------------------------- Preliminary Priority of Distributions - -------------------------------------------------------------------------------- Distributions will be made on each Distribution Date from the Pool Distribution Amount in the following order of priority: Preliminary Priority of Distributions - -------------------------------------------------------------------------------- First, to Assured Guaranty to pay its premium; - -------------------------------------------------------------------------------- | v - -------------------------------------------------------------------------------- Second, to the Senior Certificates entitled to payments of interest to pay interest; - -------------------------------------------------------------------------------- | v - -------------------------------------------------------------------------------- Third, to the Senior Certificates to pay principal; - -------------------------------------------------------------------------------- | v - -------------------------------------------------------------------------------- Fourth, to the Class A-PO Certificates to pay any applicable PO Deferred Amounts, but only from amounts that would otherwise be distributable on such Distribution Date as principal of the Subordinate Certificates. - -------------------------------------------------------------------------------- | v - -------------------------------------------------------------------------------- Fifth, sequentially, to each class of Subordinate Certificates to pay Interest and Principal in the order of numerical class designations, beginning with Class B-1 Certificates, until each class balance is zero; and - -------------------------------------------------------------------------------- | v - -------------------------------------------------------------------------------- Sixth, to Assured Guaranty, any remaining Pool Distribution Amount, up to the aggregate amount of previously unreimbursed Insured Payments; and - -------------------------------------------------------------------------------- | v - -------------------------------------------------------------------------------- Seventh, to the residual certificate, any remaining amounts. - -------------------------------------------------------------------------------- - -------------------------------------------------------------------------------- Preliminary Summary of Terms - -------------------------------------------------------------------------------- Pool Distribution Amount: The "Pool Distribution Amount" with respect to any Distribution Date will be determined by reference to amounts received and expenses incurred in connection with the Mortgage Loans and will be equal to the sum of: (i) all scheduled installments of interest (net of the related Servicing Fee) and principal due on the Mortgage Loans on the due date in the month in which such Distribution Date occurs and received prior to the related Determination Date, together with any Advances in respect thereof and any Compensating Interest allocable to the Mortgage Loans; (ii) all proceeds of any primary mortgage guaranty insurance policies and any other insurance policies with respect to the Mortgage Loans, to the extent such proceeds are not applied to the restoration of the related mortgaged property or released to the mortgagor in accordance with the Servicer's normal servicing procedures and all other cash amounts received and retained in connection with the liquidation of defaulted Mortgage Loans, by foreclosure or otherwise (collectively, "Liquidation Proceeds"), during the calendar month preceding the month of such Distribution Date (in each case, net of unreimbursed expenses incurred in connection with a liquidation or foreclosure and unreimbursed Advances, if any); (iii) all partial or full prepayments received on the Mortgage Loans during the calendar month preceding the month of such Distribution Date; and (iv) amounts received with respect to such Distribution Date as a substitution adjustment amount or purchase price in respect of any deleted Mortgage Loan or amounts received in connection with the optional termination of the Trust as of such Distribution Date, reduced by amounts in reimbursement for Advances previously made and other amounts as to which the Servicer is entitled to be reimbursed pursuant to the Pooling Agreement. Description of Servicer: All of the Mortgage Loans will be serviced by Bank of America, National Association (in its capacity as servicer, the "Servicer") in accordance with the terms of the Pooling Agreement. The Servicer may perform any of its obligations under the Pooling Agreement through one or more subservicers. Despite the existence of subservicing arrangements, the Servicer will be liable for its servicing duties and obligations under the Pooling Agreement as if the Servicer alone were servicing the Mortgage Loans. Bank of America, National Association is an indirect wholly-owned subsidiary of Bank of America Corporation. Bank of America, National Association is engaged in a general commercial banking business, offering a wide range of commercial, corporate, international, financial and retail banking services to corporations, governments and individuals. Bank of America, National Association originates and services residential mortgage loans and performs subservicing functions for affiliates. Bank of America, National Association's headquarters and its executive offices are located at 101 South Tryon Street, Charlotte, North Carolina 28255, and the telephone number is (704) 386-5478. Bank of America, National Association is subject to regulation, supervision and examination by the Office of the Comptroller of the Currency and has been approved as a mortgagee and seller/servicer by the Department of Housing and Urban Development, the Veterans Administration, the Government National Mortgage Association, Fannie Mae and Freddie Mac. Underwriting Guidelines of America, National Association: Bank of America, National Association may, as part of its overall evaluation of a prospective borrower's creditworthiness, use Credit Scores or a combination of Credit Scores and Mortgage Scores. "Credit Scores" arestatistical credit scores designed to assess a borrower's creditworthiness and likelihood to default on a consumer obligation over a two-year period based on a borrower's credit history. Credit Scores were not developed to predict the likelihood of default on mortgage loans and, accordingly, may not be indicative of the ability of a mortgagor to repay its Mortgage Loan. A "Mortgage Score" takes into account not only a borrower's credit history but also uses statistics to predict how the majority of loans with common characteristics in a broad group of the population will perform in the future. The Mortgage Score used by Bank of America, National Association will either have been developed by Bank of America, National Association or by a third party and approved by Bank of America, National Association. Some mortgage loans originated by Bank of America, National Association may have no Credit Score or Mortgage Score or have a Credit Score that Bank of America, National Association believes, as a result of other factors, is not predictive of a borrower's capacity and willingness to pay. In those cases, Bank of America, National Association will obtain an alternative credit history that has at least three credit references, one of which is housing related. A prospective borrower with (1) a higher Credit Score or (2) a higher Credit Score and Mortgage Score, which, in either event, indicates a more favorable credit history, is eligible for one of Bank of America, National Association's accelerated processing programs (the "Accelerated Processing Programs"). Loans in the Accelerated Processing Programs (which include, among others, the All-Ready Home and Rate Reduction Refinance programs described below) are subject to less stringent documentation requirements. Once the credit report and any applicable employment and deposit documentation are received, a determination is made as to whether the prospective mortgagor has sufficient monthly income available (i) to meet the mortgagor's monthly obligations on the proposed mortgage loan and other expenses related to the mortgaged property (such as property taxes and hazard insurance) and (ii) to meet other financial obligations and monthly living expenses. To determine the adequacy of the mortgaged property as collateral, generally an independent appraisal is made of each mortgaged property considered for financing. In certain instances the appraisal may be conducted by an employee of Bank of America, National Association or an affiliate. The evaluation is based on the appraiser's estimate of value, giving appropriate weight to both the market value of comparable housing, as well as the cost of replacing the mortgaged property. If the loan is a refinance of a loan currently serviced by Bank of America, National Association, or carries a conforming loan amount, the collateral valuation of the property may be established by an automated valuation or the tax assessed value. Mortgage loans will generally be covered by an appropriate standard form American Land Title Association title insurance policy, or a substantially similar policy or form of insurance acceptable to FNMA or FHLMC, or if the related mortgaged property is located in a jurisdiction where such policies are generally not available, an opinion of counsel of the type customarily rendered in such jurisdiction in lieu of title insurance will be obtained instead. Notwithstanding the foregoing, certain mortgage loans that are not purchase money mortgage loans or that have principal balances less than certain specified amounts may not be covered by title insurance policies, although title searches are performed in connection with the origination of such mortgage loans. The Depositor will represent and warrant to the Trustee that the Mortgaged Property related to each Mortgage Loan (including each Mortgage Loan for which a title search is performed in lieu of obtaining a title insurance policy) is free and clear of all encumbrances and liens having priority over the first lien of the related Mortgage, subject to certain limited exceptions. However, in the event that a lien senior to the lien of the Mortgage related to a Mortgage Loan for which a title search is performed in lieu of obtaining a title insurance policy is found to exist, the sole recourse of the Trustee will be against the Depositor for breach of its representation and warranty. The Trustee will not have recourse against any title insurance company or other party. Certain states where the mortgaged properties securing the mortgage loans are located are "anti-deficiency" states, where, in general, lenders providing credit on one-to-four family properties must look solely to the property for repayment in the event of foreclosure. Bank of America, National Association's underwriting guidelines in all states (including anti-deficiency states) require that the value of the mortgaged property being financed currently supports and is anticipated to support in the future the outstanding loan balance and provides sufficient value to mitigate the effects of adverse shifts in real estate values, although there can be no assurance that such value will support the outstanding loan balance in the future. Bank of America, National Association may provide secondary financing to a borrower contemporaneously with the origination of the first mortgage loan but only if the first mortgage loan does not have a Loan-to-Value Ratio exceeding 80% and a combined loan-to-value ratio exceeding 95%. The underwriting guidelines applied to the first mortgage loan are based on the combined higher loan-to-value ratio with the exception of the requirement of primary mortgage insurance and loan amount limit. Secondary financing by a lender other than Bank of America, National Association is not prohibited but the terms of such financing are subject to review by Bank of America, National Association and may not be as stringent as the Bank of America, National Association's underwriting guidelines for secondary financing. Bank of America, National Association may originate new mortgage loans under its "All-Ready Home" mortgage refinance program. Under this program, a borrower whose mortgage loan is serviced by Bank of America, National Association may be eligible for a reduced documentation refinancing if the borrower's mortgage loan has had no delinquent payments in the previous twelve months and the only change is to the mortgage interest rate or term of the mortgage loan. In addition, under its "Rate Reduction Refinance" program, Bank of America, National Association may offer to refinance a mortgage loan to reduce the mortgage interest rate and/or change the amortization schedule for a borrower who has indicated an interest in refinancing or who has requested payoff information, through the extension of a replacement mortgage loan or the modification of the existing mortgage loan, provided the borrower has had no delinquent mortgage loan payments in the previous twelve months. In such cases, Bank of America, National Association will not apply any significant borrower credit or property underwriting standards. Mortgage Loans may have been the subject of a refinancing described above. To the extent a borrower becomes eligible for such a refinancing after his or her Mortgage Loan has been included in a particular Trust, such Mortgage Loan could be refinanced resulting in a prepayment of such Mortgage Loan. Foreclosure and Delinquency Experience of Bank of America, National Association: The following table summarizes the delinquency and foreclosure experience on the portfolio of one- to four-family first mortgage loans originated or acquired by Bank of America, National Association or certain of its affiliates and serviced or subserviced by Bank of America, National Association or serviced by Bank of America, National Association for others, other than (i) mortgage loans acquired through certain mergers with previously unaffiliated entities, (ii) mortgage loans with respect to which the servicing rights were acquired by Bank of America, National Association in bulk and (iii) certain mortgage loans originated at bank branches of Bank of America, National Association. The portfolio of mortgage loans serviced by Bank of America, National Association includes both fixed and adjustable interest rate mortgage loans, including "buydown" mortgage loans, loans with balances conforming to Freddie Mac's and Fannie Mae's limits as well as jumbo loans, loans with stated maturities of 10 to 40 years and other types of mortgage loans having a variety of payment characteristics, and includes mortgage loans secured by mortgaged properties in geographic locations that may not be representative of the geographic distribution or concentration of the mortgaged properties securing the Mortgage Loans. There can be no assurance that the delinquency, foreclosure and loss experience set forth below will be similar to the results that may be experienced with respect to the Mortgage Loans. Bank of America, National Association Delinquency and Foreclosure Experience on Mortgage Loans At September 30, 2005 At December 31, 2004 At December 31, 2003 -------------------------- -------------------------- ------------------------- Number/ Outstanding Number/ Outstanding Number/ Outstanding % of Principal % of Principal % of Principal Mortgage Amount Mortgage Amount Mortgage Amount Loans (In Millions) Loans (In Millions) Loans (In Millions) - --------------------------------------- --------- ------------- --------- ------------- --------- ------------- Total Portfolio 1,356,316 $214,901.0 1,300,762 $194,743.4 1,229,050 $174,777.5 Delinquencies* One Installment delinquent 16,345 $1,927.5 16,251 $1,802.3 20,406 $2,219.3 Percent Delinquent 1.2% 0.9% 1.2% 0.9% 1.7% 1.3% Two Installments delinquent 4,186 $445.2 4,224 $428.3 5,399 $549.9 Percent Delinquent 0.3% 0.2% 0.3% 0.2% 0.4% 0.3% Three or more installments delinquent 4,488 $449.0 4,935 $484.0 6,294 $615.8 Percent Delinquent 0.3% 0.2% 0.4% 0.2% 0.5% 0.4% In Foreclosure 3,333 $297.2 4,296 $399.2 5,449 $548.2 Percent in Foreclosure 0.2% 0.1% 0.3% 0.2% 0.4% 0.3% Delinquent and in Foreclosure 28,352 $3,118.8 29,706 $3,113.8 37,548 $3,933.2 Percent Delinquent and in Foreclosure** 2.1% 1.5% 2.3% 1.6% 3.1% 2.3% - ---------- * A mortgage loan is deemed to have "one installment delinquent" if any scheduled payment of principal or interest is delinquent past the end of the month in which such payment was due, "two installments delinquent" if such delinquency persists past the end of the month following the month in which such payment was due, and so forth. ** The sums of the Percent Delinquent and Percent in Foreclosure set forth in this table may not equal the Percent Delinquent and in Foreclosure due to rounding. - -------------------------------------------------------------------------------- Risk Factors - -------------------------------------------------------------------------------- Subordination of Super Senior Support and Subordinate Certificates Increases Risk of Loss: Subordinate certificateholders are more likely to suffer losses as a result of losses or delinquencies on the Mortgage Loans than are Class A certificateholders. o The rights of each class of Subordinate Certificates to receive distributions of interest and principal are subordinated to the rights of the Senior Certificates and each class of Subordinate Certificates with a lower numerical designation. For example, the Class B-2 Certificates will not receive principal or interest on a distribution date until the Class A Certificates and Class B-1 Certificates have received the amounts to which they are entitled on that Distribution Date. o Losses that are realized on the Mortgage Loans will be allocated first to the Class B-6 Certificates then to the Class B-5 Certificates and so on, in reverse numerical order of the class designation, until the outstanding class balances of such classes have been reduced to zero. Super Senior Support certificateholders should consider the risk that after the Subordinate Certificates are no longer outstanding, the principal portion of losses realized on the Mortgage Loans that are allocated to the Super Senior Certificates will be borne by the Super Senior Support Certificates, rather than the Super Senior Certificates. The Rate of Principal Payments on the Mortgage Loans Will Affect the Yield on the Offered Certificates: Because principal payments on the Mortgage Loans will be distributed currently on the Senior Certificates and the Subordinate Certificates, the rate of distributions of principal and the yield to maturity on your Certificates will be directly related to (i) the rate and timing of payments of principal on the applicable Mortgage Loans and (ii) the amount and timing of defaults by borrowers that result in losses on the applicable Mortgage Loans. Borrowers are permitted to prepay their Mortgage Loans, in whole or in part, at any time. The principal payments on the Mortgage Loans may be in the form of scheduled principal payments or principal prepayments (for this purpose, the term "principal prepayment" includes prepayments and any other recovery of principal in advance of the scheduled due date, including repurchases and liquidations due to default, casualty, condemnation and the like). Any of these prepayments will result in distributions to you of amounts that would otherwise be distributed over the remaining term of the Mortgage Loans. The rate of principal payments on the Mortgage Loans will be affected by the following: o the amortization schedules of the Mortgage Loans; o the rate of partial prepayments and full prepayments by borrowers due to refinancing, job transfer, changes in property values or other factors; o liquidations of the properties that secure defaulted Mortgage Loans; o repurchases of Mortgage Loans by the Depositor as a result of defective documentation or breaches of representations or warranties; o the exercise of due-on-sale clauses by the Servicer in connection with transfers of mortgaged properties; o the optional repurchase of all the Mortgage Loans by the Depositor to effect a termination of the Trust when the aggregate Stated Principal Balance of the Mortgage Loans is less than 10% of the aggregate unpaid principal balance of the mortgage loans as of the cut-off date; and o general and targeted solicitations for refinancing by mortgage originators (including Bank of America, National Association). The rate of principal payments on the Mortgage Loans will depend greatly on the level of mortgage interest rates: o If prevailing interest rates for similar mortgage loans fall below the interest rates on the Mortgage Loans in the Trust, the rate of prepayment is likely to increase. o Conversely, if prevailing interest rates for similar mortgage loans rise above the interest rates on the Mortgage Loans in the Trust, the rate of prepayment is likely to decrease. If you are purchasing Offered Certificates at a discount, and specifically if you are purchasing the Class A-6 or Class A-PO Certificates, you should consider the risk that if principal payments on the applicable Mortgage Loans or in the case of the Class A-PO Certificates, the Discount Mortgage Loans, occur at a rate slower than you expected, your yield will be lower than you expected. If you are purchasing Offered Certificates at a premium, or are purchasing a Class A-IO Certificate (which has no class balance), you should consider the risk that if principal payments on the applicable mortgage loans or, in the case of the Class A-IO Certificates, the Mortgage Loans with a Net Mortgage Interest Rate as of the Cut-off Date greater than or equal to 5.750%, occur at a rate faster than you expected, your yield may be lower than you expected. If you are purchasing Class A-IO Certificates, you should consider the risk that a rapid rate of principal prepayments on the Mortgage Loans with a Net Mortgage Interest Rate as of the Cut-off Date greater than or equal to 5.750%, could result in your failure to recover your initial investment. If you are purchasing the Class A-3 Certificates, which are Inverse Floating Rate Certificates, you should consider the risk that a high rate of LIBOR may result in a lower yield than you expected or a negative yield. In particular, you should consider the risk that high constant rates of LIBOR or high constant prepayment rates on the Mortgage Loans may result in the failure to recover your initial investment. You must make your own decisions as to the appropriate prepayment assumptions to be used when purchasing Offered Certificates. The Senior Prepayment Percentage of all principal prepayments (excluding for this purpose, partial liquidations due to default, casualty, condemnation and the like) initially will be distributed to the classes of Senior Certificates that are entitled to receive principal prepayment distributions at that time. This may result in all (or a disproportionately high percentage) of those principal prepayments being distributed to the Senior Certificates and none (or a disproportionately low percentage) of those principal prepayments being distributed to holders of the Subordinate Certificates during the periods of time described in the definition of "Senior Prepayment Percentage." The timing of changes in the rate of prepayments may significantly affect the actual yield to you, even if the average rate of principal prepayments is consistent with your expectations. In general, the earlier the payment of principal of the Mortgage Loans, the greater the effect on your yield to maturity. As a result, the effect on your yield of principal prepayments occurring at a rate higher (or lower) than the rate you anticipate during the period immediately following the issuance of the certificates will not be offset by a subsequent like reduction (or increase) in the rate of principal prepayments. Delinquencies and Losses on the Mortgage Loans Will Adversely Affect Your Yield: Delinquencies on the mortgage loans which are not advanced by or on behalf of the Servicer (because the Servicer has determined that these amounts, if advanced, would be nonrecoverable), will adversely affect the yield on the Senior Certificates and the Subordinate Certificates. The Servicer will determine that a proposed advance is nonrecoverable when, in the good faith exercise of its servicing judgment, it believes the proposed advance would not be ultimately recoverable from the related mortgagor, related liquidation proceeds, or other recoveries in respect of the Mortgage Loan. Because of the priority of distributions, shortfalls resulting from delinquencies that are not covered by advances will be borne first by the Subordinate Certificates (in reverse numerical order), and then by the Senior Certificates. Net interest shortfalls will adversely affect the yields on the Offered Certificates. In addition, losses generally will be borne by the Subordinate Certificates. As a result, the yields on the Offered Certificates will depend on the rate and timing of realized losses on the Mortgage Loans. Credits Scores May Not Accurately Predict the Likelihood of Default: Bank of America, National Association generally uses Credit Scores as part of its underwriting process. The attached collateral annex shows credit scores for the mortgagors obtained at the time of origination of their mortgage loans. A credit score purports only to be a measurement of the relative degree of risk a borrower represents to a lender, i.e., that a borrower with a higher score is statistically expected to be less likely to default in payment than a borrower with a lower score. In addition, it should be noted that credit scores were developed to indicate a level of default probability over a two-year period, which does not correspond to the life of most mortgage loans. Furthermore, credit scores were not developed specifically for use in connection with mortgage loans, but for consumer loans in general. Therefore, credit scores do not address particular mortgage loan characteristics that influence the probability of repayment by the borrower. Neither the depositor nor Bank of America, National Association makes any representations any mortgage loan or that a particular credit score should be relied upon as a basis for an expectation that a borrower will repay its mortgage loan according to its terms. Geographic Concentration May Increase Risk of Loss Due to Adverse Economic Conditions or Natural Disasters: At various times, certain geographic regions will experience weaker economic conditions and housing markets and, consequently, will experience higher rates of delinquency and loss on mortgage loans generally. In addition, certain states have experienced natural disasters, including earthquakes, fires, floods and hurricanes, which may adversely affect property values. Although mortgaged properties located in certain identified flood zones will be required to be covered, to the maximum extent available, by flood insurance, no mortgaged properties will otherwise be required to be insured against earthquake damage or any other loss not covered by standard hazard insurance policies. Any concentration of mortgaged properties in a state or region may present unique risk considerations. See the tables entitled "Geographic Distribution of Mortgaged Properties" in the attached collateral annex for a listing of the locations and concentrations of the mortgaged properties. Any deterioration in housing prices in a state or region due to adverse economic conditions, natural disaster or other factors, and any deterioration of economic conditions in a state or region that adversely affects the ability of borrowers to make payments on the mortgage loans, may result in losses on the Mortgage Loans. Any losses may adversely affect the yield to maturity of the Offered Certificates. Residential Real Estate Values May Fluctuate and Adversely Affect Your Investment: There can be no assurance that values of the mortgaged properties have remained or will remain at their levels on the dates of origination of the related Mortgage Loans. The value of any mortgaged property generally will change over time from its value on the appraisal or sales date. If residential real estate values generally or in a particular geographic area decline, the loan-to-value ratios shown in the table in the accompanying collateral annex might not be a reliable indicator of the rates of delinquencies, foreclosures and losses that could occur on the Mortgage Loans. If the residential real estate market should experience an overall decline in property values large enough to cause the outstanding balances of the Mortgage Loans and any secondary financing on the related mortgaged properties to equal or exceed the value of the mortgaged properties, delinquencies, foreclosures and losses could be higher than those now generally experienced in the mortgage lending industry or in Bank of America, National Association's prior securitizations involving the Depositor. In addition, adverse economic conditions and other factors (which may or may not affect real property values) may affect the mortgagors' timely payment of scheduled payments of principal and interest on the Mortgage Loans and, accordingly, the actual rates of delinquencies, foreclosures and losses with respect to any Mortgage Pool. These other factors could include excessive building resulting in an oversupply of housing in a particular area or a decrease in employment reducing the demand for housing in an area. To the extent that credit enhancements do not cover such losses, your yield may be adversely impacted. United States Military Operations May Increase Risk of Relief Act Shortfalls: As a result of military operations in Afghanistan and Iraq, the United States has placed a substantial number of armed forces reservists and members of the National Guard on active duty status. It is possible that the number of reservists and members of the National Guard placed on active duty status may remain at high levels for an extended time. To the extent that a member of the military, or a member of the armed forces reserves or National Guard who is called to active duty, is a mortgagor of a mortgage loan in the trust, the interest rate limitation of the Servicemembers Civil Relief Act, and any comparable state law, will apply. This may result in interest shortfalls on the Mortgage Loans in the trust, which will be borne by all classes of interest bearing Certificates. The Policy will not cover any such shortfalls allocated to the Class A-1 Certificates. Neither Bank of America, National Association nor the depositor has not taken any action to determine whether any of the Mortgage Loans would be affected by these interest rate limitations. Distributions of Principal to the Special Retail Certificates are Subject to Special Procedures: Although there can be no assurance as to the rate at which principal distributions will be made on any class of Offered Certificates, the Special Retail Certificates, in particular, may be inappropriate investments for you if you require a distribution of a particular amount of principal on a specific date or an otherwise predictable stream of distributions. If you own Special Retail Certificates, funds available for distributions of principal may not be sufficient to permit the distributions you request within any specific period of time after your request. During periods in which prevailing interest rates are generally higher than the pass-through rate for the class of Special Retail Certificates, greater numbers of beneficial owners may request distributions of principal in respect of the Special Retail Certificates to take advantage of higher interest rates. During such periods there may, however, be a concurrent reduction in the rate of prepayments of the Mortgage Loans, thus limiting the funds available for such distributions. In addition, because of the random lot procedure for distributing principal, you may receive a principal distribution on your Special Retail Certificates on a Distribution Date (even if you have not requested such a distribution) if the amount available for distribution in respect of principal on such Distribution Date on the class of Special Retail Certificates exceeds the aggregate amount requested for distribution of principal by all holders of the class of Special Retail Certificates. It is more likely that amounts will be distributed by random lot during the periods of the relatively low interest rates and, correspondingly, higher prepayment rates. Under such circumstances you may have difficulty reinvesting these principal distributions at rates as high as the pass-through rate of your Certificates or your expected yield. There is a Risk that Interest Payments on the Mortgage Loans May Be Insufficient to Pay Interest on Your Certificates: When a Mortgage Loan is prepaid in full, the mortgagor is charged interest only up to the date on which payment is made, rather than for an entire month. When a mortgagor makes a partial principal prepayment on a Mortgage Loan, the mortgagor is not charged interest on the prepayment for the month in which the principal prepayment was received. This may result in a shortfall in interest collections available for payment on the next Distribution Date. The Servicer is required to cover a portion of the shortfall in interest collections that are attributable to prepayments in full and partial prepayments on the Mortgage Loans, but in each case only up to the amount of Compensating Interest for such Distribution Date. To the extent these shortfalls are not covered by the amount of Compensating Interest, they will be allocated pro rata to the related classes of interest-bearing Certificates. The Policy will not cover any such shortfalls allocated to the Class A-1 Certificates. Certificates May Not Be Appropriate for Individual Investors: If you are an individual investor who does not have sufficient resources or expertise to evaluate the particular characteristics of the applicable class of Offered Certificates, the Offered Certificates may not be an appropriate investment for you. This may be the case because, among other things: o if you purchase your Certificates at a price other than par, your yield to maturity will be sensitive to the uncertain rate and timing of principal prepayments on the applicable Mortgage Loans; o the rate of principal distributions on, and the weighted average lives of, the Offered Certificates will be sensitive to the uncertain rate and timing of principal prepayments on the applicable Mortgage Loans and the priority of principal distributions among the classes of Certificates, and as such, the Offered Certificates and, in particular, the Special Retail Certificates, may be inappropriate investments for you if you require a distribution of a particular amount of principal on a specific date or an otherwise predictable stream of distributions; o you may not be able to reinvest amounts distributed in respect of principal on your Certificates (which distributions, in general, are expected to be greater during periods of relatively low interest rates) at a rate at least as high as the applicable pass-through rate or your expected yield; o a secondary market for the Offered Certificates may not develop or provide you with liquidity of investment; and o you must pay tax on any interest or original issue discount in the year it accrues, even if the cash is paid to you in a different year. Limited Source of Payments -- No Recourse to Depositor, Seller, Servicer or Trustee: Proceeds of the Mortgage Loans will be the sole source of payments on the Certificates, other than the Class A-1 Certificates, as to which certain payments may be made from the Reserve Fund or under the Policy. The Certificates do not represent an interest in or obligation of the Depositor, the Servicer, the Seller, the Trustee or any of their affiliates. There are, however, limited obligations of the Depositor with respect to certain breaches of representations and warranties, and limited obligations of the Servicer with respect to its servicing obligations. Neither the Certificates nor the Mortgage Loans will be guaranteed by or insured by any governmental agency or instrumentality, the Depositor, the Seller, the Servicer, the Trustee or any of their affiliates. Consequently, if payments on the Mortgage Loans are insufficient or otherwise unavailable to make all payments required on the Certificates, there will be no recourse to the Depositor, the Seller, the Servicer, the Trustee or any of their affiliates. Limited Liquidity: The Underwriter intends to make a market for purchase and sale of the Offered Certificates after their initial issuance, but the Underwriter has no obligation to do so. There is no assurance that such a secondary market will develop or, if it does develop, that it will provide you with liquidity of investment or that it will continue for the life of the Offered Certificates. As a result, you may not be able to sell your Certificates or you may not be able to sell your Certificates at a high enough price to produce your desired return on investment. The secondary market for mortgage-backed securities has experienced periods of illiquidity and can be expected to do so in the future. Illiquidity means that there may not be any purchasers for your class of Certificates. Although any class of Certificates may experience illiquidity, it is more likely that classes of Certificates that are more sensitive to prepayment, credit or interest rate risk (such as the Interest Only, Super Senior Support, Principal Only, Inverse Floating Rate or Subordinated Certificates) will experience illiquidity. - -------------------------------------------------------------------------------- [BANC OF AMERICA SECURITIES LOGO] Banc of America Mortgage Securities, Inc. Mortgage Pass-Through Certificates, 2005-12 $298,847,554 (approximate) - -------------------------------------------------------------------------------- Appendix A Principal Balance Schedule PAC Group - ------------------ -------------------------- Initial Balance.... $136,879,000.00 January 25, 2006... $136,463,886.13 February 25, 2006.. $135,986,250.18 March 25, 2006..... $135,446,339.68 April 25, 2006..... $134,844,342.30 May 25, 2006....... $134,180,485.83 June 25, 2006...... $133,455,038.15 July 25, 2006...... $132,668,307.10 August 25, 2006.... $131,820,640.28 September 25, 2006. $130,912,424.96 October 25, 2006... $129,944,087.72 November 25, 2006.. $128,916,094.26 December 25, 2006.. $127,828,949.06 January 25, 2007... $126,683,194.95 February 25, 2007.. $125,479,412.80 March 25, 2007..... $124,218,220.99 April 25, 2007..... $122,900,274.94 May 25, 2007....... $121,526,266.60 June 25, 2007...... $120,096,923.86 July 25, 2007...... $118,613,009.93 August 25, 2007.... $117,075,322.69 September 25, 2007. $115,484,694.01 October 25, 2007... $113,841,989.00 November 25, 2007.. $112,148,105.27 December 25, 2007.. $110,403,972.11 January 25, 2008... $108,610,549.68 February 25, 2008.. $106,768,828.09 March 25, 2008..... $104,879,826.54 April 25, 2008..... $102,944,592.37 May 25, 2008....... $100,965,064.60 June 25, 2008...... $98,998,798.32 July 25, 2008...... $97,045,883.11 August 25, 2008.... $95,106,232.36 September 25, 2008. $93,179,760.04 October 25, 2008... $91,266,380.66 November 25, 2008.. $89,366,009.33 December 25, 2008.. $87,478,561.66 January 25, 2009... $85,624,718.87 February 25, 2009.. $83,783,632.67 March 25, 2009..... $81,955,220.35 April 25, 2009..... $80,139,399.73 May 25, 2009....... $78,336,089.15 June 25, 2009...... $76,545,207.52 July 25, 2009...... $74,766,674.25 August 25, 2009.... $73,000,409.28 September 25, 2009. $71,246,333.09 October 25, 2009... $69,504,366.66 November 25, 2009.. $67,774,431.49 December 25, 2009.. $66,056,449.61 January 25, 2010... $64,350,343.54 February 25, 2010.. $62,656,036.32 March 25, 2010..... $60,973,451.48 April 25, 2010..... $59,302,513.05 May 25, 2010....... $57,643,145.58 June 25, 2010...... $55,995,274.08 July 25, 2010...... $54,358,824.07 August 25, 2010.... $52,733,721.57 September 25, 2010. $51,119,893.04 October 25, 2010... $49,517,265.47 November 25, 2010.. $47,925,766.30 December 25, 201... $46,345,323.44 January 25, 2011... $44,864,602.28 February 25, 2011.. $43,394,625.19 March 25, 2011..... $41,935,321.83 April 25, 201...... $40,486,622.29 May 25, 2011....... $39,048,457.13 June 25, 2011...... $37,620,757.37 July 25, 2011...... $36,203,454.47 August 25, 2011.... $34,796,480.36 September 25, 2011. $33,399,767.40 October 25, 2011... $32,013,248.42 November 25, 2011.. $30,636,856.66 December 25, 2011.. $29,270,525.83 January 25, 2012... $27,943,204.79 February 25, 201... $26,625,668.32 March 25, 2012..... $25,317,851.80 April 25, 2012..... $24,019,691.02 May 25, 2012....... $22,731,122.22 June 25, 2012...... $21,452,082.03 July 25, 2012...... $20,182,507.52 August 25, 2012.... $18,937,853.05 September 25, 2012. $17,722,944.77 October 25, 2012... $16,537,150.93 November 25, 2012.. $15,379,852.65 December 25, 2012.. $14,250,443.67 January 25, 2013... $13,282,645.42 February 25, 2013.. $12,338,725.60 March 25, 2013..... $11,418,157.58 April 25, 2013..... $10,520,425.78 May 25, 2013....... $9,645,025.47 June 25, 2013...... $8,791,462.52 July 25, 2013...... $7,959,253.20 August 25, 2013.... $7,147,923.96 September 25, 2013. $6,357,011.24 October 25, 2013... $5,586,061.24 November 25, 2013.. $4,834,629.75 December 25, 2013.. $4,102,281.92 January 25, 2014... $3,504,166.96 February 25, 2014.. $2,920,871.48 March 25, 2014..... $2,352,061.26 April 25, 2014..... $1,797,409.34 May 25, 2014....... $1,256,595.83 June 25, 2014...... $729,307.79 July 25, 2014...... $215,239.05 August 25, 2014.... $0.00 - -------------------------------------------------------------------------------- The issuer has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, the issuer, any underwriter or any dealer participating in the offering will arrange to send you the prospectus if you request it by calling toll-free 1-800-294-1322 or you e-mail a request to dg.prospectus_distribution@bofasecurities.com. The securities may not be suitable for all investors. Banc of America Securities LLC and its affiliates may acquire, hold or sell positions in these securities, or in related derivatives, and may have an investment or commercial banking relationship with the issuer. The information contained in these materials may be based on assumptions regarding market conditions and other matters as reflected herein. Banc of America Securities LLC (the "Underwriter") makes no representation regarding the reasonableness of such assumptions or the likelihood that any such assumptions will coincide with actual market conditions or events, and these materials should not be relied upon for such purposes. The Underwriter and its affiliates, officers, directors, partners and employees, including persons involved in the preparation or issuance of these materials, may, from time to time, have long or short positions in, and buy and sell, the securities mentioned herein or derivatives thereof (including options). Information in these materials is current as of the date appearing on the material only. Information in these materials regarding any securities discussed herein supersedes all prior information regarding such securities. These materials are not to be construed as an offer to sell or the solicitation of any offer to buy any security in any jurisdiction where such an offer or solicitation would be illegal. - -------------------------------------------------------------------------------- [BANC OF AMERICA SECURITIES LOGO] - -------------------------------------------------------------------------------- The asset-backed securities referred to in these materials, and the asset pools backing them, are subject to modification or revision (including the possibility that one or more classes of securities may be split, combined or eliminated at any time prior to issuance or availability of a final prospectus) and are offered on a "when, as and if issued" basis. You understand that, when you are considering the purchase of these securities, a contract of sale will come into being no sooner than the date on which the relevant class has been priced and we have confirmed the allocation of securities to be made to you; any "indications of interest" expressed by you, and any "soft circles" generated by us, will not create binding contractual obligations for you or us. Because the asset-backed securities are being offered on a "when, as and if issued" basis, any such contract will terminate, by its terms, without any further obligation or liability between us, if the securities themselves, or the particular class to which the contract relates, are not issued. Because the asset-backed securities are subject to modification or revision, any such contract also is conditioned upon the understanding that no material change will occur with respect to the relevant class of securities prior to the closing date. If a material change does occur with respect to such class, our contract will terminate, by its terms, without any further obligation or liability between us (the "Automatic Termination"). If an Automatic Termination occurs, we will provide you with revised offering materials reflecting the material change and give you an opportunity to purchase such class. To indicate your interest in purchasing the class, you must communicate to us your desire to do so within such timeframe as may be designated in connection with your receipt of the revised offering materials. MBS New Issue Term Sheet - Collateral Appendix Banc of America Mortgage 2005-12 Trust Mortgage Pass-Through Certificates, Series 2005-12 $298,847,554 (approximate) Banc of America Mortgage Securities, Inc. (Depositor) Bank of America, National Association Seller and Servicer [BANK OF AMERICA LOGO] December 20, 2005 - -------------------------------------------------------------------------------- The issuer has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, the issuer, any underwriter or any dealer participating in the offering will arrange to send you the prospectus if you request it by calling toll-free 1-800-294-1322 or you e-mail a request to dg.prospectus_distribution@bofasecurities.com. The securities may not be suitable for all investors. Banc of America Securities LLC and its affiliates may acquire, hold or sell positions in these securities, or in related derivatives, and may have an investment or commercial banking relationship with the issuer. The information contained in these materials may be based on assumptions regarding market conditions and other matters as reflected herein. Banc of America Securities LLC (the "Underwriter") makes no representation regarding the reasonableness of such assumptions or the likelihood that any such assumptions will coincide with actual market conditions or events, and these materials should not be relied upon for such purposes. The Underwriter and its affiliates, officers, directors, partners and employees, including persons involved in the preparation or issuance of these materials, may, from time to time, have long or short positions in, and buy and sell, the securities mentioned herein or derivatives thereof (including options). Information in these materials is current as of the date appearing on the material only. Information in these materials regarding any securities discussed herein supersedes all prior information regarding such securities. These materials are not to be construed as an offer to sell or the solicitation of any offer to buy any security in any jurisdiction where such an offer or solicitation would be illegal. - -------------------------------------------------------------------------------- - -------------------------------------------------------------------------------- [BANC OF AMERICA SECURITIES LOGO] Banc of America Mortgage Securities, Inc. Mortgage Pass-Through Certificates, 2005-12 $298,847,554 (approximate) - -------------------------------------------------------------------------------- IRS CIRCULAR 230 NOTICE THIS FREE WRITING PROSPECTUS IS NOT INTENDED OR WRITTEN TO BE USED, AND CANNOT BE USED, FOR THE PURPOSE OF AVOIDING U.S. FEDERAL, STATE OR LOCAL TAX PENALTIES. THIS FREE WRITING PROSPECTUS IS WRITTEN AND PROVIDED BY THE UNDERWRITERS IN CONNECTION WITH THE PROMOTION OR MARKETING OF THE TRANSACTIONS OR MATTERS ADDRESSED HEREIN. INVESTORS SHOULD SEEK ADVICE BASED ON THEIR PARTICULAR CIRCUMSTANCES FROM AN INDEPENDENT TAX ADVISOR. - -------------------------------------------------------------------------------- Collateral Summary - -------------------------------------------------------------------------------- Description of The Mortgage Loans The Mortgage Loans consist of fixed rate, conventional, fully amortizing mortgage loans secured by first liens on one- to three-family residential properties. The majority of the Mortgage Loans will have original terms to stated maturity of approximately 30 years and principal balances at origination in excess of the conforming loan balance limits established by FHLMC. Borrowers are permitted to prepay their Mortgage Loans, in whole or in part, at any time without penalty. Accordingly, the actual date on which any Mortgage Loan is paid in full may be earlier than the stated maturity date due to unscheduled payments of principal. - -------------------------------------------------------------------------------- The tables set forth below contain approximate statistical information as of the Cut-off Date regarding all Mortgage Loans. The balances and percentages may not be exact due to rounding. Collateral Summary Range (if applicable) - ------------------------------------------------------- ------------------ ---------------------- Total Outstanding Loan Balance $300,350,131 Total Number of Loans 529 Average Loan Principal Balance $567,770 $298,156 to $1,948,012 WA Gross Coupon 5.937% 5.125% to 7.125% WA FICO 746 621 to 819 WA Original Term 357 months 240 to 360 months WA Remaining Term 356 months 239 to 360 months WA OLTV 69.40% 23.81% to 90.00% Geographic Concentration of Mortgaged Properties (Top 5 CA 47.47% States) based on the Aggregate Stated Principal Balance FL 8.05% TX 4.90% MA 3.71% VA 3.63% Mortgage Loan Data All Discount Premium Mortgage Loans Mortgage Loans Mortgage Loans - ------------------------------------------------------ ---------------------- ---------------------- ---------------------- Number of Mortgage Loans 529 388 141 Aggregate Stated Principal Balance (1) $300,350,131 $221,795,965 $78,554,166 Range of Original Terms to Stated Maturity (1) 240 to 360 months 240 to 360 months 240 to 360 months Range of Stated Principal Balances (1) $298,156 to $1,948,012 $298,156 to $1,948,012 $403,514 to $1,067,785 Average Stated Principal Balance (1) $567,770 $571,639 $557,122 Latest Stated Maturity Date 12/01/2035 12/01/2035 12/01/2035 Range of Current Mortgage Interest Rates (1) 5.125% to 7.125% 5.125% to 6.000% 6.125% to 7.125% Weighted Average Current Mortgage Interest Rate (1) 5.94% 5.82% 6.27% Range of Remaining Terms to Stated Maturity (1) 239 to 360 months 239 to 360 months 239 to 360 months Weighted Average Remaining Term to Stated Maturity (1) 356 months 357 months 354 months Range of Original Loan-to-Value Ratios (1) 23.81% to 90.00% 23.81% to 90.00% 32.63% to 80.00% Weighted Average Original Loan-to-Value Ratio (1) 69.40% 69.40% 69.41% (1) Approximate. Occupancy of Mortgaged Properties of the Mortgage Loans (1) Aggregate % of Number Of Stated Principal Cut-off Date Mortgage Balance as of Pool Principal Occupancy Loans Cut-off Date Balance - ----------------------------- --------- ----------------- -------------- Primary Residence 483 $273,113,768.82 90.93% Second Home 46 27,236,361.70 9.07 - ----------------------------- --------- ----------------- -------------- Total: 529 $300,350,130.52 100.00% (1) Based solely on representations of the mortgagor at the time of origination of the related Mortgage Loan. Property Types of the Mortgage Loans Aggregate % of Number Of Stated Principal Cut-off Date Mortgage Balance as of Pool Principal Property Type Loans Cut-off Date Balance - ----------------------------- --------- ----------------- -------------- Single Family Residence 364 $203,903,094.12 67.89% PUD-Detached 97 56,249,697.41 18.73 Condominium 48 27,818,200.13 9.26 2-Family 6 4,375,922.26 1.46 PUD-Attached 7 3,679,193.67 1.22 3-Family 3 2,094,927.16 0.70 Townhouse 3 1,742,081.08 0.58 Cooperative 1 487,014.69 0.16 - ----------------------------- --------- ----------------- -------------- Total: 529 $300,350,130.52 100.00% Mortgage Loan Purpose of the Mortgage Loans Aggregate % of Number Of Stated Principal Cut-off Date Mortgage Balance as of Pool Principal Purpose Loans Cut-off Date Balance - ----------------------------- --------- ----------------- -------------- Purchase 286 $165,810,510.89 55.21% Refinance-Rate/Term 126 73,434,913.79 24.45 Refinance-Cashout 117 61,104,705.84 20.34 - ----------------------------- --------- ----------------- -------------- Total: 529 $300,350,130.52 100.00% Geographical Distribution of the Mortgage Properties of the Mortgage Loans (1) Aggregate % of Number Of Stated Principal Cut-off Date Mortgage Balance as of Pool Principal Geographic Area Loans Cut-off Date Balance - ----------------------------- --------- ----------------- -------------- Alabama 1 $671,246.99 0.22% Arizona 9 5,177,177.61 1.72 Arkansas 1 422,601.32 0.14 California 252 142,586,159.76 47.47 Colorado 8 5,063,191.59 1.69 Connecticut 4 2,059,191.66 0.69 District of Columbia 5 2,525,392.79 0.84 Florida 45 24,169,838.43 8.05 Georgia 6 3,107,379.72 1.03 Hawaii 1 824,138.65 0.27 Idaho 2 1,263,402.69 0.42 Illinois 15 8,889,072.41 2.96 Indiana 3 1,344,546.70 0.45 Kansas 2 1,496,674.23 0.50 Kentucky 1 494,483.19 0.16 Maine 3 1,631,997.96 0.54 Maryland 18 9,470,561.91 3.15 Massachusetts 19 11,145,637.95 3.71 Michigan 3 1,608,140.21 0.54 Minnesota 6 2,880,970.59 0.96 Missouri 2 1,021,054.62 0.34 Nevada 11 5,265,174.90 1.75 New Hampshire 2 2,723,257.66 0.91 New Jersey 9 5,589,026.93 1.86 New Mexico 2 975,720.91 0.32 New York 12 7,538,596.05 2.51 North Carolina 3 1,863,667.66 0.62 Ohio 2 1,030,994.49 0.34 Oklahoma 1 464,714.29 0.15 Oregon 1 782,342.74 0.26 Pennsylvania 8 4,844,617.32 1.61 Rhode Island 3 1,655,827.28 0.55 South Carolina 8 4,833,128.74 1.61 Tennessee 1 431,515.92 0.14 Texas 24 14,728,360.27 4.90 Utah 1 799,239.31 0.27 Vermont 3 1,797,074.61 0.60 Virginia 20 10,909,570.08 3.63 Washington 11 5,768,911.01 1.92 Wisconsin 1 495,529.37 0.16 - ----------------------------- --------- ----------------- -------------- Total: 529 $300,350,130.52 100.00% (1) As of the Cut-off Date, no more than approximately 0.88% of the Mortgage Loans are expected to be secured by mortgaged properties in any one five-digit postal zip code. Current Mortgage Loan Principal Balances of the Mortgage Loans (1) Aggregate % of Number Of Stated Principal Cut-off Date Current Mortgage Loan Mortgage Balance as of Pool Principal Principal Balances ($) Loans Cut-off Date Balance - ----------------------------- --------- ----------------- -------------- 250,000.01 - 300,000.00 1 $298,156.13 0.10% 400,000.01 - 450,000.00 104 45,002,448.34 14.98 450,000.01 - 500,000.00 136 64,835,057.31 21.59 500,000.01 - 550,000.00 78 40,974,789.51 13.64 550,000.01 - 600,000.00 54 31,124,798.02 10.36 600,000.01 - 650,000.00 49 30,703,414.22 10.22 650,000.01 - 700,000.00 34 23,033,503.35 7.67 700,000.01 - 750,000.00 13 9,359,873.86 3.12 750,000.01 - 800,000.00 14 10,871,972.42 3.62 800,000.01 - 850,000.00 11 9,125,177.10 3.04 850,000.01 - 900,000.00 12 10,514,470.19 3.50 900,000.01 - 950,000.00 5 4,571,358.58 1.52 950,000.01 - 1,000,000.00 11 10,889,486.15 3.63 1,000,000.01 - 1,500,000.00 6 7,097,613.45 2.36 1,500,000.01 - 2,000,000.00 1 1,948,011.89 0.65 - ----------------------------- --------- ----------------- -------------- Total: 529 $300,350,130.52 100.00% (1) As of the Cut-off Date, the average outstanding principal balance of the Mortgage Loans is expected to be approximately $567,770. Original Loan-To-Value Ratios of the Mortgage Loans (1) Aggregate % of Number Of Stated Principal Cut-off Date Original Loan-To-Value Ratios Mortgage Balance as of Pool Principal (%) Loans Cut-off Date Balance - ----------------------------- --------- ----------------- -------------- 20.01 - 25.00 1 $630,870.00 0.21% 25.01 - 30.00 1 449,530.17 0.15 30.01 - 35.00 3 1,315,275.73 0.44 35.01 - 40.00 17 9,311,078.36 3.10 40.01 - 45.00 9 5,718,907.30 1.90 45.01 - 50.00 25 13,890,247.34 4.62 50.01 - 55.00 28 14,983,992.95 4.99 55.01 - 60.00 37 19,853,583.95 6.61 60.01 - 65.00 43 25,778,914.93 8.58 65.01 - 70.00 69 41,873,064.25 13.94 70.01 - 75.00 48 26,904,253.50 8.96 75.01 - 80.00 243 137,339,689.34 45.73 85.01 - 90.00 5 2,300,722.70 0.77 - ----------------------------- --------- ----------------- -------------- Total: 529 $300,350,130.52 100.00% (1) As of the Cut-off Date, the weighted average Loan-to-Value Ratio at origination of the Mortgage Loans is expected to be approximately 69.40%. Current Mortgage Interest Rates of the Mortgage Loans (1) Aggregate % of Number Of Stated Principal Cut-off Date Current Mortgage Mortgage Balance as of Pool Principal Interest Rates (%) Loans Cut-off Date Balance - ----------------------------- --------- ----------------- -------------- 5.001 - 5.250 6 $3,118,940.24 1.04% 5.251 - 5.500 25 13,187,505.39 4.39 5.501 - 5.750 125 71,717,336.13 23.88 5.751 - 6.000 232 133,772,182.86 44.54 6.001 - 6.250 104 57,954,088.82 19.30 6.251 - 6.500 29 16,012,828.48 5.33 6.501 - 6.750 6 3,492,146.90 1.16 6.751 - 7.000 1 539,546.33 0.18 7.001 - 7.250 1 555,555.37 0.18 - ----------------------------- --------- ----------------- -------------- Total: 529 $300,350,130.52 100.00% (1) As of the Cut-off Date, the weighted average Current Mortgage Interest Rate of the Mortgage Loans is expected to be approximately 5.937% per annum. Remaining Terms of the Mortgage Loans (1) Aggregate % of Number Of Stated Principal Cut-off Date Mortgage Balance as of Pool Principal Remaining Term (Months) Loans Cut-off Date Balance - ----------------------------- --------- ----------------- -------------- 221 - 240 11 $6,133,046.68 2.04% 281 - 300 1 576,095.96 0.19 341 - 360 517 293,640,987.88 97.77 - ----------------------------- --------- ----------------- -------------- Total: 529 $300,350,130.52 100.00% (1) As of the Cut-off Date, the weighted average remaining term to stated maturity of the Mortgage Loans is expected to be approximately 356 months. Credit Scoring of Mortgagors of the Mortgage Loans (1) Aggregate % of Number Of Stated Principal Cut-off Date Mortgage Balance as of Pool Principal Credit Scores Loans Cut-off Date Balance - ----------------------------- --------- ----------------- -------------- 801 - 850 29 $17,939,571.66 5.97% 751 - 800 256 147,873,786.94 49.23 701 - 750 153 86,818,402.71 28.91 651 - 700 72 37,717,111.20 12.56 601 - 650 19 10,001,258.01 3.33 - ----------------------------- --------- ----------------- -------------- Total: 529 $300,350,130.52 100.00% (1) The scores shown are Bureau Credit Scores from Experian (FICO), Equifax (Beacon) and TransUnion (Empirica).