This announcement is neither an offer to purchase nor a solicitation of an offer
to sell these securities. The Offer is made only by the Offer to Purchase, dated
June 11, 2002 (the "Offer to Purchase") and the related Letter of Transmittal
and is being made to all holders of Shares. The Offer is not being made to (nor
will tenders be accepted from or on behalf of) holders of Shares in any
jurisdiction in which the making of the Offer or the acceptance thereof would
not be in compliance with the laws of such jurisdiction or any administrative or
judicial action pursuant thereto.

                           Notice of Offer to Purchase
                     All Outstanding Shares of Common Stock

                                       of

                          OFFICIAL PAYMENTS CORPORATION

                                       at

                           $3.00 Net Per Share in Cash

                                       by

                        Kingfish Acquisition Corporation
                          a Wholly-Owned Subsidiary of

                             TIER TECHNOLOGIES, INC.

     Tier Technologies, Inc., a California corporation ("Parent"), and its
wholly-owned subsidiary, Kingfish Acquisition Corporation, a Delaware
corporation ("Purchaser"), hereby offers to purchase all outstanding shares of
common stock, par value $0.01 per share (the "Shares"), of Official Payments
Corporation, a Delaware corporation (the "Company"), at a price of $3.00 per
Share, net to the seller in cash, without interest thereon, upon the terms and
subject to the conditions set forth in the Offer to Purchase and in the related
Letter of Transmittal (which, together with any amendments or supplements
thereto, constitute the "Offer").

- --------------------------------------------------------------------------------
     THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 5:00 p.m., NEW YORK CITY
          TIME, ON TUESDAY, JULY 9, 2002, UNLESS THE OFFER IS EXTENDED.
- --------------------------------------------------------------------------------

     The Offer is conditioned upon, among other things, there being validly
tendered and not properly withdrawn prior to the Expiration Date that number of
shares which would represent at least a majority of the Shares outstanding on a
fully diluted basis (provided that for the purposes of the foregoing
calculation, "fully-diluted" means giving effect to the conversion or exercise
of all options exercisable or convertible into Shares at an exercise price of
$3.00 or less per Share, whether or not exercised or converted at the time of
determination).

     The Offer is being made pursuant to an Agreement and Plan of Merger, dated
as of May 30, 2002 (the "Merger Agreement"), by and among Parent, Purchaser and
the Company. Pursuant to the Merger Agreement and in accordance with the
Delaware General Corporation Law (the "DGCL"), as soon as practicable after the
completion of the Offer and satisfaction or waiver, if permissible, of all
conditions, including the purchase of Shares pursuant to the Offer and the
approval and adoption of the Merger Agreement by the stockholders of the Company
(if required by applicable law), Purchaser will be merged with and into the
Company (the "Merger"), with the Company as the surviving corporation. At the
effective time of the Merger, each Share then outstanding, other than Shares
held by (i) the Company or any of its subsidiaries, (ii) Parent, Purchaser or
any of its subsidiaries and (iii) stockholders who have properly exercised their
dissenters' rights under the DGCL, will be cancelled and converted automatically
into the right to receive $3.00 in cash, or any higher price per Share paid in
the Offer, without interest.

     In connection with the Merger Agreement, certain stockholders of the
Company, representing approximately 55.8% of the Shares outstanding on a
fully-diluted basis, have executed a Stockholders Agreement, pursuant to which
each such person has agreed to tender all Shares owned pursuant to the Offer,
and in any event to vote in favor of the Merger Agreement and the Merger and
against certain competing proposals to purchase the Company with respect to any
Shares such stockholder may own as of the record date of a stockholder's meeting
at which such matters will be considered.

     The Board of Directors of the Company has unanimously determined that the
Merger Agreement and the transactions contemplated thereby, including the Offer
and the Merger, are advisable, fair to, and in the best interests of, the
Company's stockholders and has approved the Merger Agreement and the
transactions contemplated thereby, including the Offer and Merger and
unanimously recommends that the Company's stockholders accept the Offer and
tender their Shares pursuant thereto.

     For purposes of the Offer, Purchaser will be deemed to have accepted for
payment, and therefore purchased, Shares that are validly tendered and not
withdrawn only when and if it gives written notice to Mellon Investor Services
LLC (the "Depositary") of its acceptance of the Shares for payment pursuant to
the Offer. For Shares to be validly tendered pursuant to the Offer (a) the
certificates for such Shares (or confirmation of receipt of such Shares pursuant
to the procedure for book-entry transfer), together with a properly completed
and duly executed Letter of Transmittal (or a manually signed facsimile
thereof), including any required signature guarantees, and any other documents
required by the Letter of Transmittal, must be received prior to the Expiration
Date by the Depositary at its address set forth on the back cover of the Offer
to Purchase, or (b) the tendering stockholder must comply with the guaranteed
delivery procedure set forth in the Offer to Purchase.

     If, prior to the Expiration Date, Purchaser increases the consideration
offered to holders of Shares pursuant to the Offer, such increased consideration
will be paid to all holders of Shares that are purchased pursuant to the Offer,
whether or not such Shares were tendered prior to such increase in
consideration. Under no circumstances will interest on the purchase price for
Shares be paid by Purchaser by reason of any delay in making such payment.

     The term "Expiration Date" means 5:00 p.m., New York City time, on July 9,
2002, unless and until Purchaser, in accordance with the terms of the Offer and
subject to the limitations in the Merger Agreement, shall have extended the
period of time for which the Offer is open, in which event the term "Expiration
Date" will mean the time and date at which the Offer, as so extended by
Purchaser, will expire. Purchaser expressly reserves the right, subject to the
terms of the Merger Agreement, to extend the Offer as more fully described in
Section 1 of the Offer to Purchase. Any such extension will be followed by a
public announcement thereof by no later than 9:00 a.m., New York City time, on
the next business day after the previously scheduled Expiration Date. During any
such extension, all Shares previously tendered and not withdrawn will remain
subject to the Offer, subject to the right of a tendering stockholder to
withdraw such Shares. Without limiting the manner in which Purchaser may choose
to make any public announcement, Purchaser currently intends to make
announcements by issuing a press release to the Business Wire news service.

     Pursuant to Rule 14d-11 under the Securities Exchange Act of 1934, as
amended (the "Exchange Act"), Purchaser may, subject to certain conditions,
include a subsequent offering period following the expiration of the Offer. A
subsequent offering period, if one is included, is not an extension of the
Offer. A subsequent offering period would be an additional period of time,
following the expiration of the Offer, within which stockholders may tender
Shares not tendered in the Offer. Purchaser does not currently intend to include
a subsequent offering period in the Offer, although it reserves the right to do
so in its sole discretion.

     Except as otherwise provided below or as provided by applicable law,
tenders of Shares made pursuant to the Offer are irrevocable. Shares tendered
pursuant to the Offer may be withdrawn at any time on or prior to the Expiration
Date and, unless theretofore accepted for payment as provided herein, may also
be withdrawn at any time after August 10, 2002 (or such later date as may apply
in case the Offer is extended).

     To be effective, a written, telegraphic or facsimile transmission notice of
withdrawal must be timely received by the Depositary at one of its addresses set
forth on the back cover of the Offer to Purchase. Any such notice of withdrawal
must specify the name of the person who tendered the Shares to be withdrawn, the
number of Shares to be withdrawn and the name of the registered holder of the
Shares to be withdrawn, if different from the name of the person who tendered
the Shares. If certificates evidencing Shares to be withdrawn have been
delivered or otherwise identified to the Depositary, then, prior to the physical
release of such certificates, the serial numbers shown on such certificates must
be submitted to the Depositary and, unless such Shares have been tendered by an
Eligible Institution (as defined in the Offer to Purchase), the signatures on
the notice of withdrawal must be guaranteed by an Eligible Institution. If
Shares have been delivered pursuant to the procedures for book-entry transfer as
set forth in the Offer, any notice of withdrawal must also specify the name and
number of the


account at the Book-Entry Transfer Facility to be credited with the withdrawn
Shares and otherwise comply with such Book-Entry Transfer Facility's procedures.

     Withdrawals of Shares may not be rescinded. Any Shares properly withdrawn
will be deemed not validly tendered for purposes of the Offer, but may be
retendered at any subsequent time prior to the Expiration Date by following any
of the procedures described in Offer. No withdrawal rights will apply to Shares
tendered during any subsequent offering period and no withdrawal rights apply
during any such subsequent offering period with respect to shares tendered in
the Offer and accepted for payment.

     All questions as to the form and validity (including time of receipt) of
notices of withdrawal will be determined by Purchaser, in its sole discretion,
whose determination will be final and binding.

     The receipt of cash in exchange for Shares pursuant to the Offer (or the
Merger) will be a taxable transaction for federal income tax purposes and may
also be a taxable transaction under applicable state, local or foreign tax laws.
Generally, a stockholder who receives cash in exchange for Shares pursuant to
the Offer (or the Merger) will recognize gain or loss for federal income tax
purposes equal to the difference (if any) between the amount of cash received
and such stockholder's adjusted tax basis in the Shares exchanged therefor.
Provided that such Shares constitute capital assets in the hands of the
stockholder, such gain or loss will be capital gain or loss and will be
long-term capital gain or loss if the holder has held the Shares for more than
one year at the time of the exchange. All stockholders should consult with their
tax advisors as to the particular tax consequences of the Offer and the Merger
to them, including the applicability and effect of the alternative minimum tax
and any state, local or foreign income and other tax laws and of changes in such
tax laws. For a more complete description of certain U.S. federal income tax
consequences of the Offer and the Merger, see Section 5 of the Offer to
Purchase.

     The Information required to be disclosed by paragraph (d)(1) of Rule 14d-6
under the Securities Exchange Act of 1934, as amended, is contained in the Offer
to Purchase and is incorporated herein by reference.

     The Company has provided Purchaser with the Company's stockholder lists and
security position listings for the purpose of disseminating the Offer to holders
of Shares. The Offer to Purchase, the related Letter of Transmittal and other
materials will be mailed to record holders of Shares and will be furnished to
brokers, dealers, banks and similar persons whose names, or the names of whose
nominees, appear on the stockholder lists or, if applicable, who are listed as
participants in a clearing agency's security position listing, for subsequent
transmittal to beneficial owners of Shares.

     The Offer to Purchase, the related Letter of Transmittal and Official
Payment's Solicitation/Recommendation Statement on Schedule 14D-9 contain
important information that should be read before any decision is made with
respect to the Offer. These documents and any amendments to these documents will
be filed with the United States Securities and Exchange Commission, and may be
obtained for free at the SEC's website (www.sec.gov).

     Any questions or requests for assistance or for copies of the Offer to
Purchase and the related Letter of Transmittal and other tender offer materials
may be directed to the Information Agent as set forth below, and copies will be
furnished promptly at the Company's expense. No fees or commissions will be
payable to brokers, dealers or other persons (other than the Information
Agent/Depositary and Dealer Manager) for soliciting tenders of Shares pursuant
to the Offer.

               The Information Agent/Depositary for the Offer is:

                          Mellon Investor Services LLC
                            44 Wall Street, 7th Floor
                            New York, New York 10005

                         Call Toll Free: (866) 323-8166

                      The Dealer Manager for the Offer is:
                          Adams, Harkness & Hill, Inc.
                                 60 State Street
                           Boston, Massachusetts 02109
                                 (617) 371-3777

June 11, 2002