STOCKHOLDERS AGREEMENT


     THIS STOCKHOLDERS AGREEMENT, dated as of May 30, 2002 (this "Agreement"),
by and among Tier Technologies, Inc., a California corporation ("Parent"),
Kingfish Acquisition Corporation, a Delaware corporation and wholly owned
subsidiary of Parent ("Purchaser"), and each of the stockholders of the Company
set forth on Schedule A hereto (each, a "Stockholder" and, collectively, the
"Stockholders").

                                    RECITALS:

     A. Parent, Purchaser and Official Payments Corporation, a Delaware
corporation (the "Company") propose to enter into an Agreement and Plan of
Merger, dated as of the date hereof (the "Merger Agreement"), pursuant to which
Purchaser will acquire the Company in a tender offer followed by a merger on the
terms and subject to the conditions set forth in the Merger Agreement. Except as
otherwise defined herein, terms used herein with initial capital letters have
the respective meanings ascribed thereto in the Merger Agreement.

     B. As of the date hereof, each Stockholder beneficially owns and is
entitled to dispose of (or to direct the disposition of) and to vote (or to
direct the voting of) the number of Shares of the Company set forth opposite
such Stockholder's name on Schedule A hereto (such Shares, together with any
other Shares the beneficial ownership of which is acquired by such Stockholder,
through the exercise of the Stock Options as set forth on Schedule A or
otherwise, during the period from and including the date hereof through and
including the date on which this Agreement is terminated pursuant to Section 5.2
hereof, are collectively referred to herein as such Stockholder's "Subject
Shares").

     C. As a condition and inducement to their willingness to enter into the
Merger Agreement, Parent and Purchaser have requested that each Stockholder
agree, and each Stockholder has agreed, to enter into this Agreement.

     NOW, THEREFORE, in consideration of the foregoing and the representations,
warranties and covenants contained in this Agreement, and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto hereby agree as follows:

                           I. TENDER OF SUBJECT SHARES

     1.1 Agreement to Tender Shares. Each Stockholder will tender or cause to be
validly tendered (and not withdrawn) pursuant to and in accordance with the
terms of the Offer and Rule 14d-2 promulgated under the Securities Exchange Act
of 1934, not later than the tenth business day after commencement of the Offer
and will cause to remain validly tendered and not withdrawn until termination of
this Agreement, all of such Stockholder's Subject Shares. Each Stockholder
hereby acknowledges that Purchaser's obligation to accept for payment and pay
the Offer Price for Shares (including such Stockholder's Subject Shares)
pursuant to the Offer is subject to the terms and conditions of the Offer set
forth in the Merger Agreement.


                          II. VOTING OF SUBJECT SHARES

     2.1 Agreement to Vote Subject Shares. From the date hereof until this
Agreement is terminated pursuant to Section 5.2, at any meeting of the
stockholders of the Company called to consider and vote upon the adoption of the
Merger Agreement (and at any and all postponements and adjournments thereof),
and in connection with any action to be taken in respect of the adoption of the
Merger Agreement by written consent of stockholders of the Company, each
Stockholder will vote or cause to be voted (including by written consent, if
applicable) all of such Stockholder's Subject Shares which it has the right to
vote in favor of the adoption of the Merger Agreement and in favor of any other
matter necessary or appropriate for the consummation of the transactions
contemplated by the Merger Agreement that is considered and voted upon at any
such meeting or made the subject of any such written consent, as applicable. At
any meeting of the stockholders of the Company called to consider and vote upon
any Adverse Proposal (and at any and all postponements and adjournments
thereof), and in connection with any action to be taken in respect of any
Adverse Proposal by written consent of stockholders of the Company, each
Stockholder will vote or cause to be voted (including by written consent, if
applicable) all of such Stockholder's Subject Shares which it has the right to
vote against the adoption of such Adverse Proposal. For purposes of this
Agreement, the term "Adverse Proposal" means (a) any Company Takeover Proposal,
(b) any proposal or action that would reasonably be expected to result in a
breach of any covenant, agreement, representation or warranty of the Company set
forth in this Agreement or the Merger Agreement, or (c) the following actions
(other than the Offer, the Merger and the other transactions contemplated by the
Merger Agreement): (i) any extraordinary corporate transaction, such as a
merger, consolidation or other business combination involving the Company or the
Company Subsidiary; (ii) a sale, lease, disposition or transfer of a material
amount of assets of the Company or the Company Subsidiary, or a reorganization,
recapitalization, dissolution or liquidation of the Company or the Company
Subsidiary; and (iii) (1) any change in a majority of the persons who constitute
the Company Board as of the date hereof; (2) any change in the present
capitalization of the Company or any amendment of the Company's certificate of
incorporation or bylaws, as amended to date; (3) any other material change in
the Company's corporate structure or business; or (4) any other action that is
intended, or could reasonably be expected, to impede, interfere with, delay,
postpone, or adversely affect the Offer or the Merger and the other transactions
contemplated by this Agreement and the Merger Agreement or increase the
likelihood that such transactions will not be consummated.

     2.2 Irrevocable Proxy.

          (a) Grant of Proxy. Each Stockholder hereby appoints Parent and any
designee of Parent, each of them individually, such Stockholder's proxy and
attorney-in-fact, with full power of substitution and resubstitution, to vote or
act by written consent with respect to all of such Stockholder's Subject Shares
which it has the right to vote (i) in accordance with Section 2.1 hereof and
(ii) to sign its name (as a stockholder) to any consent, certificate or other
document relating to the Company that the law of the State of Delaware may
permit or require in connection with any matter referred to in Section 2.1. This
proxy is given to secure the performance of the duties of such Stockholder under
this Agreement and its existence will not be deemed to relieve the Stockholders
of their obligations under Section 2.1. Each Stockholder affirms that this proxy
is coupled with an interest and is irrevocable until termination of this


                                       2


Agreement pursuant to Section 5.2, whereupon such proxy and power of attorney
shall automatically terminate. Each Stockholder will take such further action or
execute such other instruments as may be necessary to effectuate the intent of
this proxy. For Subject Shares as to which the Stockholder is the beneficial but
not the record owner, the Stockholder will cause any record owner of such
Subject Shares to grant to Parent a proxy to the same effect as that contained
herein.

          (b) Other Proxies Revoked. Each Stockholder represents that any proxy
heretofore given in respect of such Stockholder's Subject Shares is not
irrevocable, and hereby revokes any and all such proxies.

                       III. REPRESENTATIONS AND WARRANTIES

     3.1 Certain Representations and Warranties of the Stockholders. Each
Stockholder, severally and not jointly, represents and warrants to Parent and
Purchaser, as of the date hereof, as follows:

          (a) Ownership. Such Stockholder is the sole record and beneficial
owner of the number of Shares and Stock Options set forth opposite such
Stockholder's name on Schedule A hereto, has full and unrestricted power to
dispose of and to vote such Shares. The Subject Shares are now, and at all times
during the term hereof will be, held by such Stockholder, or by a nominee or
custodian for the benefit of such Stockholder, free and clear of all Liens and
proxies, except for any Liens or proxies arising hereunder. Except as set forth
opposite the Stockholder's name on Schedule A hereto, such Stockholder (i) does
not beneficially own any securities of the Company on the date hereof; (ii) does
not, directly or indirectly, beneficially own or have any option, warrant or
other right to acquire any securities of the Company that are or may by their
terms become entitled to vote or any securities that are convertible or
exchangeable into or exercisable for any securities of the Company that are or
may by their terms become entitled to vote, nor is the Stockholder subject to
any contract, commitment, arrangement, understanding or relationship (whether or
not legally enforceable), other than this Agreement, that allows or obligates
him to vote, dispose of or acquire any securities of the Company; and (iii)
holds exclusive power to vote the Subject Shares and has not granted a proxy to
any other person to vote the Subject Shares, subject to the limitations set
forth in this Agreement.

          (b) Power and Authority; Execution and Delivery. Each Stockholder that
is a limited partnership, limited liability company or corporation is duly
organized, validly existing and in good standing under the laws of the
jurisdiction of its organization. Each Stockholder has all requisite power and
authority, and if an individual, the legal capacity, to execute and deliver this
Agreement and to consummate the transactions contemplated hereby, and has taken
all necessary action to authorize the execution, delivery and performance of
this Agreement. This Agreement has been duly executed and delivered by the
Stockholder and constitutes a valid and binding obligation of the Stockholder,
enforceable against the Stockholder in accordance with its terms.

          (c) No Conflicts. The execution and delivery of this Agreement do not,
and, subject to compliance with the HSR Act and appropriate filings under
securities laws (which each Stockholder agrees to make promptly), to the extent
applicable, the consummation of the


                                       3


transactions contemplated hereby and compliance with the provisions hereof will
not, conflict with, result in a violation or breach of, or constitute a default
(or an event that, with notice or lapse of time or both, would result in a
default) or give rise to any right of termination, amendment, cancellation,
notice or acceleration under, (i) the Stockholder's certificate of
incorporation, certificate of limited partnership, articles of organization,
operating agreement, partnership agreement or similar constituent documents,
(ii) any material contract, commitment, agreement, understanding, arrangement or
restriction of any kind to which the Stockholder is a party or by which the
Stockholder is bound, (iii) any injunction judgment, writ, decree, order or
ruling applicable to the Stockholder or (iv) any law, statute, rule or
regulation applicable to the Stockholder; except in the case of clauses (ii) and
(iii) for violations, breaches or defaults that would not (1) impair the ability
of the Stockholder to perform its obligations under this Agreement or (2)
prevent or delay the consummation of any of the transactions contemplated
hereby.

          (d) Brokers. Except as set forth in Section 3.01(n) of the Merger
Agreement, no broker, finder or investment banker is entitled to any brokerage,
finder's or other fee or commission in connection with the transactions
contemplated by this Agreement or the Merger Agreement based upon arrangements
made by or on behalf of the Stockholder that is or will be payable by the
Company or the Company Subsidiary.

     3.2 Representations and Warranties of Parent. Parent hereby represents and
warrants as of the date hereof, that:

          (a) Due Incorporation. Each of the Parent and Purchaser is a
corporation duly organized, validly existing and in good standing under the laws
of its jurisdiction of incorporation and has the corporate power to carry on its
business as it is now being conducted and to own, operate or lease all of its
properties and assets.

          (b) Due Authorization of Transaction; Binding Obligation. Each of
Parent and Purchaser has full corporate power and authority to execute and
deliver this Agreement and to perform its obligations hereunder, and the
execution, delivery and performance of this Agreement by Parent and Purchaser
have been duly authorized by all necessary corporate action on the part of
Parent and Purchaser; this Agreement has been duly executed and delivered by
Parent and Purchaser and is the valid and binding obligation of Parent and
Purchaser enforceable in accordance with its terms, subject to the
qualification, however, that enforcement of the rights and remedies created
hereby is subject to bankruptcy, insolvency, fraudulent transfer,
reorganization, moratorium and similar laws of general application relating to
or affecting creditors' rights and to general equity principles.

          (c) Non-Contravention. The execution, delivery and performance of this
Agreement by Parent and Purchaser and the consummation of the transactions
contemplated hereby do not and will not (a) contravene the certificate of
incorporation or bylaws or other charter or organizational documents of Parent
or Purchaser, and (b) conflict with or result in a breach of or constitute a
default (or an event which with notice or lapse of time or both would become a
default) under, or give to others any rights of termination, amendment,
acceleration or cancellation of, or result in any loss of any material benefit,
or the creation of any Lien on any of the property or assets of the Parent and
each of its subsidiaries pursuant to any judgment, decree,


                                       4


order or ruling to which Parent and each of its subsidiaries is a party or by
which it or any of its assets or properties is bound or affected, except for
such contraventions, violations, conflicts, breaches, defaults, rights creation
or lien creation which individually or in the aggregate would not prevent or
materially delay the consummation of the transactions contemplated hereby or the
performance by Parent or Purchaser of any of their respective obligations
hereunder.

                      IV. CERTAIN COVENANTS OF STOCKHOLDERS

     4.1 Restriction on Transfer of Subject Shares, Proxies and Noninterference.
No Stockholder will, directly or indirectly: (a) except pursuant to the terms of
this Agreement and for the conversion of Subject Shares into the right to
receive the Offer Price at the Effective Time pursuant to the terms of the
Merger Agreement, offer for sale, sell, transfer, tender, pledge, encumber,
gift, assign or otherwise dispose of, or enter into any contract, option or
other arrangement or understanding with respect to or consent to the offer for
sale, sale, transfer, tender, pledge, encumbrance, gift-over, assignment or
other disposition of, any or all of such Stockholder's Subject Shares; (b)
acquire any Shares or other securities of the Company (other than in connection
with a transaction of the type described in Section 4.2) or enter into any
contract, option, arrangement or other undertaking with respect to the direct or
indirect acquisition of any interest in or the voting of any Subject Shares or
any other securities of the Company; (c) except pursuant to the terms of this
Agreement, grant any proxies or powers of attorney, deposit any Subject Shares
into a voting trust or enter into a voting agreement with respect to any Subject
Shares; or (d) take any action that would reasonably be expected to make any of
its representations or warranties contained herein untrue or incorrect or have
the effect of impairing the ability of such Stockholder to perform such
Stockholder's obligations under this Agreement or preventing or delaying the
consummation of any of the transactions contemplated hereby.

     4.2 Adjustments. In the event (a) of any stock dividend, stock split,
recapitalization, reclassification, combination or exchange of shares of capital
stock or other securities of the Company on, of or affecting the Shares or the
like or any other action that would have the effect of changing a Stockholder's
ownership of the Company's capital stock or other securities or (b) a
Stockholder becomes the beneficial owner of any additional Shares or other
securities of the Company, then the terms of this Agreement will apply to the
shares of capital stock held by the Stockholder immediately following the
effectiveness of the events described in clause (a) or the Stockholder becoming
the beneficial owner thereof, as described in clause (b), as though they were
Subject Shares hereunder. Each Stockholder hereby agrees, while this Agreement
is in effect, to promptly notify Parent of the number of any new Shares acquired
by the Stockholder, if any, after the date hereof.

     4.3 Takeover Proposals; Non-Solicitation.

          (a) Company Takeover Proposal. Each Stockholder will, and will cause
its officers, directors, employees, agents or representatives (including any
investment banker, financial advisor, attorney or accountant for such
Stockholder) ("Representatives") to notify Parent, the Purchaser and the Company
promptly, and in all events within 24 hours, (or will determine that Parent, the
Purchaser and the Company have been notified) if any proposals are received by,
any information is requested from, or any negotiations or discussions are sought
to


                                       5


be initiated or continued with such Stockholder or its Representatives in
connection with any Company Takeover Proposal indicating, in connection with
such notice, the name of the person indicating such Company Takeover Proposal
and the material terms and conditions of any proposals or offers. Each
Stockholder agrees, severally and not jointly, that he, she or it will
immediately cease and cause to be terminated any existing activities,
discussions or negotiations with any parties conducted heretofore with respect
to the possibility or consideration of any Company Takeover Proposal and will
not take, authorize or permit any of its Representatives to take, any action
that the Company would be prohibited from taking under Section 4.02 of the
Merger Agreement. Such Stockholder will keep Parent, the Purchaser and the
Company fully informed, on a current basis, of the status and terms of any
Company Takeover Proposal.

          (b) Non-Solicitation. Each Stockholder shall not and shall not
authorize or permit its Representatives to directly or indirectly to (i)
initiate, solicit or encourage (including by way of furnishing information or
assistance), or take any other action to facilitate the making of, any offer or
proposal which constitutes or is reasonably likely to lead to any Company
Takeover Proposal, (ii) enter into any agreement with respect to any Company
Takeover Proposal, or (iii) in the event of an unsolicited Company Takeover
Proposal for the Company, engage in negotiations or discussions with, or provide
any information or data to, any person (other than Parent or any of its
affiliates or representatives) relating to any Company Takeover Proposal.

          (c) Fiduciary Responsibilities. Notwithstanding any provision of this
Section 4.3 or Section 4.6 of this Agreement to the contrary, (a) if any
Stockholder is a member of the Company Board, such member of the Company Board
may take actions in such capacity to the extent permitted by Section 4.02 of the
Merger Agreement, and (b) if any Stockholder is an officer of the Company, such
officer may take actions in such capacity to the extent directed to do so by the
Company Board in compliance with Section 4.02 of the Merger Agreement.

     4.4 Waiver of Appraisal Rights. Each Stockholder hereby waives any rights
of appraisal or rights to dissent from the Merger that such Stockholder may
have.

     4.5 Nonexercise of Rights of First Refusal. No Stockholder will exercise
any purchase right or right of first refusal that it may have with respect to
any Shares of any other person in connection with any tender by such other
person of such Shares pursuant to the Offer.

     4.6 Cooperation. Each Stockholder will cooperate fully with Parent,
Purchaser and the Company in connection with their respective reasonable best
efforts to fulfill the conditions to (a) the Offer set forth in Annex A to the
Merger Agreement and (b) the Merger set forth in Article V of the Merger
Agreement.

     4.7 Disclosure. Each Stockholder hereby authorizes Parent and Purchaser to
publish and disclose in the Offer Documents, any announcement or disclosure
required by the SEC and the NASDAQ Stock Market and, if approval of the
Company's stockholders is required under applicable law, the Proxy Statement
(including all documents and schedules filed with the SEC in connection with
either of the foregoing), its identity and ownership of the Subject Shares and
the nature of its commitments, arrangements and understandings under this
Agreement.


                                       6


                                V. MISCELLANEOUS

     5.1 Fees and Expenses. Each party hereto will pay its own expenses incident
to preparing for, entering into and carrying out this Agreement and the
consummation of the transactions contemplated hereby.

     5.2 Termination. This Agreement will terminate on the earliest to occur of
(a) the Effective Time, (b) the date the Merger Agreement is terminated in
accordance with its terms, or (c) September 30, 2002. This Agreement may be
earlier terminated by the mutual consent of the Board of Directors of Parent and
the Stockholders representing a majority of the Subject Shares subject to this
Agreement. Except as set forth below, in the event of termination of this
Agreement pursuant to this Section 5.2, this Agreement will become null and void
and of no effect with no liability on the part of any party hereto and all
proxies granted hereby will be automatically revoked; provided, however, that no
such termination will relieve any party hereto from any liability for any breach
of this Agreement occurring prior to such termination. Notwithstanding anything
to the contrary contained in this Agreement, (a) if this Agreement is terminated
for any reason, Sections 5.1, 5.5, 5.15 and 5.16 and this Section 5.2 will
survive any termination of this Agreement indefinitely.

     5.3 Extension; Waiver. Any agreement on the part of a party to waive any
provision of this Agreement, or to extend the time for any performance
hereunder, will be valid only if set forth in an instrument in writing signed on
behalf of such party. The failure of any party to this Agreement to assert any
of its rights under this Agreement or otherwise will not constitute a waiver of
such rights. Any waiver by any party of a breach of any provision of this
Agreement will not operate as or be construed as a waiver of any other breach of
such provision or of any breach of any other provision of this Agreement. The
failure of a party to insist upon strict adherence to any term of this Agreement
or one or more sections hereof will not be considered a waiver or deprive that
party of a right thereafter to insist upon strict adherence to that term or any
other term of this Agreement.

     5.4 Entire Agreement; No Third-Party Beneficiaries; Several Obligations.
This Agreement and the Merger Agreement constitute the entire agreement among
the parties hereto with respect to the subject matter hereof, and supersede all
prior agreements and understandings, both written and oral, among the parties
with respect to such matters. Neither the Merger Agreement nor this Agreement is
intended to confer upon any person other than the parties hereto any rights or
remedies. The obligations of, and the representations and warranties made by,
each Stockholder shall be several and not joint and shall relate only to such
Stockholder.

     5.5 Governing Law. This Agreement will be governed by, and construed in
accordance with, the laws of the State of Delaware regardless of the laws that
might otherwise govern under applicable principles of conflict of laws thereof.

     5.6 Notices. Any notice required to be given hereunder will be sufficient
if in writing, and sent by facsimile transmission and by courier service (with
proof of service), hand delivery or certified or registered mail (return receipt
requested and first-class postage prepaid), addressed as follows:


                                       7


          If to Parent or Purchaser:

          Tier Technologies, Inc.
          1350 Treat Boulevard, Suite 250
          Walnut Creek, CA 94596
          Telecopy No.: (925) 937-3902
          Attention: James L. Bildner

          With copies to:

          Farella Braun + Martel LLP
          235 Montgomery St.
          San Francisco, CA 94104
          Telecopy No.: (415) 954-4480
          Attention: Bruce R. Deming, Esq.

          If to any Stockholder:

          To the address listed in Schedule A hereto.

          With copies to:

          The recipient listed in Schedule A hereto,

or to such other address as any party specifies by written notice, such notice
being deemed to have been delivered as of the date so telecommunicated,
personally delivered or mailed.

     5.7 Assignment. Neither this Agreement nor any of the rights, interests, or
obligations under this Agreement may be assigned or delegated, in whole or in
part (except by operation of law or otherwise), by any Stockholder without the
prior written consent of Parent or by Parent without the consent of the
applicable Stockholder (and then only with respect to such Stockholder), and any
such assignment or delegation that is not consented to will be null and void;
provided that this Agreement, together with any rights, interests, or
obligations of Parent hereunder, may be assigned or delegated, in whole or in
part, by Parent to any direct or indirect wholly owned subsidiary of Parent
without the consent of or any action by any Stockholder upon notice by Parent to
each Stockholder affected thereby as herein provided. Subject to the preceding
sentence, this Agreement will be binding upon, inure to the benefit of, and be
enforceable by, the parties and their respective successors and assigns
(including, without limitation, any person to whom any Subject Shares are sold,
transferred or assigned).

     5.8 Further Assurances. Each Stockholder will execute and deliver such
other documents and instruments and take such further actions as may be
necessary or appropriate or as may be reasonably requested by Parent in order to
ensure that Parent and Purchaser receive the full benefit of this Agreement.

     5.9 Publicity. Parent, Purchaser, the Company and each Stockholder will
consult with each other party before issuing any press release or otherwise
making any public statements with respect to this Agreement or the Merger
Agreement or the other transactions contemplated


                                       8


hereby or thereby and will not issue any such press release or make any such
public statement before such consultation, except as may be required by law or
applicable stock exchange rules.

     5.10 Enforcement. Irreparable damage would occur in the event that any of
the provisions of this Agreement were not performed in accordance with their
specific terms or were otherwise breached. Accordingly, the parties will be
entitled to an injunction or injunctions to prevent breaches of this Agreement
and to enforce specifically the terms and provisions of this Agreement, this
being in addition to any other remedy to which they are entitled at law or in
equity.

     5.11 Severability. Whenever possible, each provision or portion of any
provision of this Agreement will be interpreted in such a manner as to be
effective and valid under applicable law but if any provision or portion of any
provision of this Agreement is held to be invalid, illegal or unenforceable in
any respect under any applicable law or rule in any jurisdiction, such
invalidity, illegality or unenforceability will not affect any other provision
or portion of any provision in such jurisdiction, and this Agreement will be
reformed, construed and enforced in such jurisdiction as if such invalid,
illegal or unenforceable provision or portion of any provision had never been
contained herein.

     5.12 Counterparts. This Agreement may be executed in one or more
counterparts, all of which will be considered one and the same instrument and
will become effective when one or more counterparts have been signed by each
party and delivered to the other parties.

     5.13 Headings. The descriptive headings contained herein are for
convenience and reference only and will not affect in any way the meaning or
interpretation of this Agreement.

     5.14 Remedies Not Exclusive. All rights, powers and remedies provided under
this Agreement or otherwise available in respect hereof at law or in equity will
be cumulative and not alternative, and the exercise of any thereof by either
party will not preclude the simultaneous or later exercise of any other such
right, power or remedy by such party.

     5.15 Jurisdiction; Consent to Service of Process. Each of the parties
hereto (a) consents to submit itself to the personal jurisdiction of any federal
court located in the State of Delaware or any Delaware state court in the event
any dispute arises out of this Agreement or any of the transactions contemplated
by this Agreement, (b) agrees that it will not attempt to deny or defeat such
personal jurisdiction by motion or other request for leave from any such court,
and (c) agrees that it will not bring any action relating to this Agreement or
any of the transactions contemplated by this Agreement in any court other than a
federal court sitting in the State of Delaware or a Delaware state court.

     5.16 Several Parties. All representations, warranties, covenants and
agreements of each of the Stockholders shall be the several and not joint,
representations, warranties, covenants and agreements of such Stockholders.

     5.17 Waiver of Jury Trial. EACH OF THE PARTIES HERETO IRREVOCABLY WAIVES
ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY LEGAL PROCEEDING ARISING OUR OF OR
RELATED TO THIS AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY.


                                       9


     IN WITNESS WHEREOF, each of the parties hereto has caused this Agreement to
be signed as of the day and year first written above.


PARENT:

Tier Technologies, Inc., a California
corporation


By: /s/ Jim Bildner
    --------------------------
Name: Jim Bildner
Title: its CEO


PURCHASER:

Kingfish Acquisition Corporation, a
Delaware corporation


By: /s/ Jim Bildner
    --------------------------
Name: Jim Bildner
Title: its CEO

STOCKHOLDERS:


Comerica Incorporated:                 Michaella  Stern:


By: /s/ Michael H. Michalak
    --------------------------
Name: Michael H. Michalak              By: /s/ Michaella Stern
Title: Senior Vice President               -------------------
                                       Name: Michaella Stern
                                       Title: n/a


Beranson Holdings, Inc.

By: /s/ Michaella Stern
    --------------------------
Name:  Michaella Stern
Title: President


                                       10


Acknowledged and Approved Only For
Purposes of Section 203 of the Delaware
General Corporation Law:

COMPANY:

Official Payments Corporation, a Delaware
corporation



By: /s/ Thomas R. Evans
    --------------------------
Name: Thomas R. Evans
Title: Chairman & CEO


                   [Signature Page to Stockholders Agreement]


                                       11


                                   SCHEDULE A

NAME AND ADDRESS OF STOCKHOLDER           COMMON SHARES   STOCK OPTIONS
- -------------------------------           -------------   -------------

Comerica Incorporated                       12,000,000          0
500 Woodward Avenue
Detroit, Michigan 48275-4013
Attn:  Corporate Planning & Development

With copies to:

Comerica Incorporated
500 Woodward Avenue
Detroit, Michigan 48275-3391
Attn:  General Counsel


Beranson Holdings, Inc.                      2,642,000
2328 Saddleback Dr.
Danville, CA 94506
Attn:  Michaella Stern

With copies to:

Gary Brett Beeler
18 Crow Canyon Court
Suite 320
San Ramon, CA 94583


Michaella Stern
2328 Saddleback Dr.                                          199,252
Danville, CA 94506
Attn:  Michaella Stern

With copies to:

Gary Brett Beeler
18 Crow Canyon Court
Suite 320
San Ramon, CA 94583

TOTAL                                       14,642,000       199,252