<PAGE>

                                                                    EXHIBIT 10.2

                                    GUARANTY

          THIS GUARANTY (this "Guaranty"), dated as of May 22, 2007, is among
WRIGHT EXPRESS CORPORATION, a Delaware corporation (the "Borrower"), each of the
Subsidiary Guarantors party hereto (each, an "Initial Subsidiary Guarantor"),
any other Person (as defined in the Credit Agreement referred to below) which
may become a Subsidiary Guarantor hereunder pursuant to a duly executed joinder
agreement in the form attached as Exhibit A hereto (each an "Additional
Subsidiary Guarantor"; each Initial Subsidiary Guarantor or Additional
Subsidiary Guarantor is referred to herein as a "Subsidiary Guarantor", and they
are referred to collectively as the "Subsidiary Guarantors") and Bank of
America, N.A., as administrative agent (in such capacity, the "Administrative
Agent") for the Lenders (as defined in the Credit Agreement referred to below).

          Reference is made to that certain Credit Agreement, dated as of the
date hereof (as in effect from time to time, the "Credit Agreement"), among the
Borrower, each lender from time to time party thereto, Bank of America, N.A., as
Administrative Agent, Swing Line Lender and L/C Issuer, SunTrust Bank, Inc., as
Syndication Agent and BMO Capital Markets, KeyBank National Association and TD
Banknorth, N.A., as Co-Documentation Agents. Capitalized terms used and not
defined herein (including, without limitation, the term "Obligations") are used
with the meanings assigned to such terms in the Credit Agreement.

          The Lenders have agreed to make Loans to the Borrower, and the L/C
Issuer has agreed to issue Letters of Credit, in each case pursuant to, and upon
the terms and subject to the conditions specified in, the Credit Agreement. Each
Subsidiary Guarantor is a Subsidiary of the Borrower and acknowledges that it
has derived and will derive substantial benefit from the making of the Loans by
the Lenders to the Borrower and the issuance of the Letters of Credit by the L/C
Issuer. As consideration therefor, and in order to induce the Lenders to make
Loans and to induce the L/C Issuer to issue Letters of Credit for the account of
the Borrower, each Subsidiary Guarantor is willing to execute and deliver this
Guaranty.

          Accordingly, the parties hereto agree as follows:

          Section 1. Guarantee. Each Subsidiary Guarantor unconditionally
guarantees, jointly with the other Subsidiary Guarantors, and any other
guarantors of the Obligations under the Credit Agreement and other Loan
Documents, and severally, as a primary obligor and not merely as a surety, the
due and punctual payment and performance of the Obligations. To the fullest
extent permitted by applicable law, each Subsidiary Guarantor waives notice of,
or any requirement for further assent to, any agreements or arrangements
whatsoever by the Administrative Agent, the Lenders, and each other Indemnitee
or other Persons to whom any part of the Obligations may be owed (collectively,
the "Guaranteed Parties"), with any other person pertaining to the Obligations,
including agreements and arrangements for payment, extension, renewal,
subordination, composition, arrangement, discharge or release of the whole or
any part of the Obligations, or for the discharge or surrender of any or all
security, or for the compromise, whether by way of acceptance of part payment or
otherwise, and, to the fullest extent permitted by applicable law, the same
shall in no way impair each Subsidiary Guarantor's liability hereunder.

<PAGE>

          Section 2. Obligations Not Waived. To the fullest extent permitted by
applicable law, each Subsidiary Guarantor waives presentment to, demand of
payment from and protest to the Borrower or any other Person of any of the
Obligations, and also waives notice of acceptance of its guarantee, notice of
protest for nonpayment and all other formalities. To the fullest extent
permitted by applicable law, the guarantee of each Subsidiary Guarantor
hereunder shall not be affected by (a) the failure of any Person to assert any
claim or demand or to enforce or exercise any right or remedy against the
Borrower or any guarantor under the provisions of the Credit Agreement, any
other Loan Document or otherwise; (b) any extension, renewal or increase of or
in any of the Obligations; (c) any rescission, waiver, amendment or modification
of, or any release from, any of the terms or provisions of this Guaranty, the
Credit Agreement, any other Loan Document, any guarantee or any other agreement
or instrument, including with respect to any guarantor under the Loan Documents;
or (d) the failure or delay of any Guaranteed Party to exercise any right or
remedy against any Loan Party or any other guarantor of the Obligations.

          Section 3. Guarantee of Payment. Each Subsidiary Guarantor further
agrees that its guarantee constitutes a guarantee of payment and performance
when due and not of collection, and, to the fullest extent permitted by
applicable law, waives any right to require that any resort be had by the
Administrative Agent or any other Guaranteed Party to any security held for
payment of the Obligations or to any balance of any deposit account or credit on
the books of the Administrative Agent or any other Guaranteed Party in favor of
the Borrower or any other Person.

          Section 4. No Discharge or Diminishment of Guarantee; Payments. (a) To
the fullest extent permitted by applicable law and except as otherwise expressly
provided in this Guaranty, the obligations of each Subsidiary Guarantor
hereunder shall not be subject to any reduction, limitation, impairment or
termination for any reason (other than the indefeasible payment in full in cash
of the Obligations (other than contingent indemnification obligations), the
termination of all Commitments and the Cash Collateralization of all L/C
Obligations in accordance with the terms of the Credit Agreement), including any
claim of waiver, release, surrender, alteration or compromise of any of the
Obligations, and shall not be subject to any defense (other than a defense of
payment) or setoff, counterclaim, recoupment or termination whatsoever by reason
of the invalidity, illegality or unenforceability of the Obligations or
otherwise. Without limiting the generality of the foregoing, the obligations of
each Subsidiary Guarantor hereunder shall, to the fullest extent permitted by
applicable law, not be discharged or impaired or otherwise affected by the
failure of the Administrative Agent or any other Guaranteed Party to assert any
claim or demand or to enforce any remedy under the Credit Agreement, any other
Loan Document, any guarantee or any other agreement or instrument, by any
amendment, waiver or modification of any provision of the Credit Agreement or
any other Loan Document or other agreement or instrument, by any default,
failure or delay, willful or otherwise, in the performance of the Obligations,
or by any other act, omission or delay to do any other act that may or might in
any manner or to any extent vary the risk of any guarantor or that would
otherwise operate as a discharge of any Subsidiary Guarantor as a matter of law
or equity (other than the indefeasible payment in full in cash of all the
Obligations (other than contingent indemnification obligations), the termination
of all Commitments and the Cash Collateralization of all L/C Obligations in
accordance with the terms of the Credit Agreement) or which would impair or
eliminate any right of any Subsidiary Guarantor to subrogation.

                                     - 2 -

<PAGE>

          (b) All payments hereunder shall be made without setoff or
counterclaim and free and clear of and without deduction for any taxes, levies,
imposts, duties, charges, fees, deductions, withholdings, compulsory loans,
restrictions or conditions of any nature now or hereafter imposed or levied by
any jurisdiction or any political subdivision thereof or taxing or other
authority therein, except to the extent expressly provided otherwise in Article
III of the Credit Agreement. If any Subsidiary Guarantor is compelled by law to
make any such deduction or withholding, it will make such deduction or
withholding and comply with Article III of the Credit Agreement as if it were a
Borrower. The obligations of the Subsidiary Guarantors under this Section 4(b)
shall survive the payment in full of the Obligations and the termination hereof.

          Section 5. Defenses Waived. To the fullest extent permitted by
applicable law, each Guarantor waives any defense based on or arising out of the
unenforceability of the Obligations or any part thereof from any cause or the
cessation from any cause of the liability (other than the final and indefeasible
payment in full in cash of the Obligations (other than contingent
indemnification obligations), the termination of all Commitments and the Cash
Collateralization of all L/C Obligations in accordance with the terms of the
Credit Agreement) of the Borrower or any other Person. Subject to the terms of
the other Loan Documents, the Administrative Agent and the other Guaranteed
Parties may, at their election, foreclose on any security held by one or more of
them by one or more judicial or nonjudicial sales, accept an assignment of any
such security in lieu of foreclosure, compromise or adjust any part of the
Obligations, make any other accommodation with the Borrower, any Subsidiary
Guarantor or any other guarantor or exercise any other right or remedy available
to them against any Borrower or any other guarantor, without affecting or
impairing in any way the liability of each Subsidiary Guarantor hereunder except
to the extent the Obligations (other than contingent indemnification
obligations) have been fully, finally and indefeasibly paid in cash. Pursuant to
and to the fullest extent permitted by applicable law, each Subsidiary Guarantor
waives any defense arising out of any such election even though such election
operates, pursuant to applicable law, to impair or to extinguish any right of
reimbursement or subrogation or other right or remedy of each Subsidiary
Guarantor against the Borrower or any other guarantor or any security.

          Section 6. Agreement to Pay; Subordination; Waiver of Subrogation;
Stay of Acceleration.

      (a) In furtherance of the foregoing and not in limitation of any other
right that the Administrative Agent or any other Guaranteed Party has at law or
in equity against each Subsidiary Guarantor by virtue hereof, upon the failure
of the Borrower or any other Loan Party to pay any Obligation when and as the
same shall become due, whether at maturity, by acceleration, after notice of
prepayment or otherwise, each Subsidiary Guarantor hereby promises to and will
forthwith pay, or cause to be paid, to the Administrative Agent or such other
Guaranteed Party as designated thereby in cash an amount equal to the unpaid
principal amount of such Obligations then due, together with accrued and unpaid
interest on such Obligations.

                                     - 3 -

<PAGE>

     (b) Upon payment by each Subsidiary Guarantor of any sums to the
Administrative Agent or any Guaranteed Party as provided above, all rights of
each Subsidiary Guarantor against the Borrower or any other guarantor arising as
a result thereof by way of right of subrogation, contribution, reimbursement,
indemnity or otherwise shall in all respects be subordinate and junior in right
of payment to the prior indefeasible payment in full in cash of all the
Obligations (other than contingent indemnification obligations) and the Cash
Collateralization of all L/C Obligations in accordance with the terms of the
Credit Agreement. In addition, any indebtedness of the Borrower or any
Subsidiary now or hereafter held by each Subsidiary Guarantor is hereby
subordinated in right of payment to the prior payment in full of the
Obligations. If any amount shall be paid to any Subsidiary Guarantor on account
of (i) any such subrogation, contribution, reimbursement, indemnity or similar
right or (ii) any such indebtedness, in each case at any time when any
Obligation then due and owing has not been paid, such amount shall be held in
trust for the benefit of the Guaranteed Parties and shall forthwith be paid to
the Administrative Agent to be credited against the payment of the Obligations,
whether matured or unmatured, in accordance with the terms of the Loan
Documents. This Section 6(b) shall not, in the absence of any continuing Event
of Default, limit the making of any loan by the Borrower or any of its
Subsidiaries, or any payment in respect thereof, to the extent such loan is
permitted under Sections 7.02 and 7.03 of the Credit Agreement.

     (c) No Subsidiary Guarantor shall exercise any right of subrogation,
contribution, indemnity, reimbursement or similar rights with respect to any
payments it makes hereunder until all of the Obligations (other than contingent
indemnification obligations) have been indefeasibly paid in full in cash, all
Commitments have been terminated and all L/C Obligations have been Cash
Collateralized in accordance with the terms of the Credit Agreement. If any
amounts are paid to any Subsidiary Guarantor in violation of the foregoing
limitation, then such amounts shall be held in trust for the benefit of the
Guaranteed Parties and shall forthwith be paid to the Administrative Agent to
reduce the amount of the Obligations, whether matured or unmatured.

     (d) In the event that acceleration of the time for payment of any of the
Obligations is stayed, in connection with any case commenced by or against any
Loan Party or any other Person under any Debtor Relief Laws or otherwise, all
such amounts shall nonetheless be payable by the Subsidiary Guarantors
immediately upon demand.

          Section 7. General Limitation on Guarantee Obligations. In any action
or proceeding involving any state corporate law, or any state, federal or
foreign bankruptcy, insolvency, reorganization or other law affecting the rights
of creditors generally, if the obligations of any Subsidiary Guarantor under
this Guaranty would otherwise be held or determined to be void, voidable,
invalid or unenforceable, or subordinated to the claims of any other creditors,
on account of the amount of its liability under this Guaranty, then,
notwithstanding any other provision to the contrary, the amount of such
liability shall, without any further action by any Subsidiary Guarantor, any
creditor or any other Person, be automatically limited and reduced to the
highest amount that is valid and enforceable and not subordinated to the claims
of other creditors as determined in such action or proceeding.

                                     - 4 -

<PAGE>

          Section 8. Information. Each Subsidiary Guarantor assumes all
responsibility for being and keeping itself informed of the Borrower's financial
condition and assets, all other circumstances bearing upon the risk of
nonpayment of the Obligations and the nature, scope and extent of the risks that
each Subsidiary Guarantor assumes and incurs hereunder and agrees that none of
the Administrative Agent or the other Guaranteed Parties will have any duty to
advise such Subsidiary Guarantor of information known to it or any of them
regarding such circumstances or risks.

          Section 9.  [Reserved].

          Section 10. Termination. When all the Obligations (other than
contingent indemnity obligations) have been indefeasibly paid in full, all
Commitments of the Lenders shall have terminated and all L/C Obligations have
been Cash Collateralized in accordance with the provisions of the Credit
Agreement, this Guaranty shall terminate; provided that this Guaranty shall
continue to be effective or be reinstated, as the case may be, if at any time
any payment, or any part thereof, on any Obligation is rescinded or must
otherwise be restored by any Guaranteed Party upon the bankruptcy or
reorganization of the Borrower, any other Loan Party or any other guarantor or
otherwise.

          Section 11. Binding Effect; Several Agreement; Assignments; Releases.
Whenever in this Guaranty any of the parties hereto is referred to, such
reference shall be deemed to include the successors and assigns of such party;
and all covenants, promises and agreements by or on behalf of each Subsidiary
Guarantor that are contained in this Guaranty shall bind and inure to the
benefit of each party hereto and their respective successors and assigns. This
Guaranty shall become effective as to each Subsidiary Guarantor when a
counterpart hereof executed on behalf of each Subsidiary Guarantor shall have
been delivered to the Administrative Agent and a counterpart hereof shall have
been executed on behalf of the Administrative Agent, and thereafter shall be
binding upon each Subsidiary Guarantor and the Administrative Agent and their
respective successors and assigns, and shall inure to the benefit of each
Subsidiary Guarantor, the Administrative Agent and the other Guaranteed Parties,
and their respective successors and assigns, except that neither the Borrower
nor any Subsidiary Guarantor shall have the right to assign its rights or
obligations hereunder or any interest herein without the prior written consent
of the Administrative Agent and the Required Lenders (and any such attempted
assignment shall be void). The Administrative Agent is hereby expressly
authorized to, and agrees upon request of the Borrower it will, release any
Subsidiary Guarantor from its obligations hereunder in the event that all the
Equity Interests of such Subsidiary Guarantor shall be sold, transferred or
otherwise disposed of, whether by merger, consolidation or otherwise, to a
person other than the Borrower or any of its Subsidiaries in a transaction
permitted by the Credit Agreement. The Administrative Agent will, at such
Subsidiary Guarantor's expense, execute and deliver to such Subsidiary Guarantor
such documents as such Subsidiary Guarantor shall reasonably request to evidence
the release of such Subsidiary Guarantor pursuant to this Section 11.

                                     - 5 -

<PAGE>

          Section 12. Waivers; Amendment. (a) No failure or delay of the
Administrative Agent in exercising any power or right hereunder shall operate as
a waiver thereof, nor shall any single or partial exercise of any such right or
power, or any abandonment or discontinuance of steps to enforce such a right or
power, preclude any other or further exercise thereof or the exercise of any
other right or power. The rights and remedies of the Administrative Agent
hereunder and of the other Guaranteed Parties under the other Loan Documents are
cumulative and are not exclusive of any rights or remedies that they would
otherwise have. No waiver of any provision of this Guaranty or consent to any
departure by any Subsidiary Guarantor therefrom shall in any event be effective
unless the same shall be permitted by subsection (b) below, and then such waiver
or consent shall be effective only in the specific instance and for the purpose
for which given. No notice or demand on any Subsidiary Guarantor in any case
shall entitle such Subsidiary Guarantor to any other or further notice or demand
in similar or other circumstances.

          (b) Neither this Guaranty nor any provision hereof may be waived,
amended or modified except pursuant to a written agreement entered into between
the Borrower and the Administrative Agent (with the consent of the Lenders to
the extent required under the Credit Agreement).

          SECTION 13.  GOVERNING LAW.  THIS GUARANTY SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

          Section 14. Notices. All communications and notices hereunder shall be
in writing and given as provided in Section 10.02 of the Credit Agreement. All
communications and notices hereunder to each Subsidiary Guarantor shall be given
to it at its respective address set forth in Schedule I with a copy to the
Borrower.

          Section 15. Survival of Agreement; Severability. (a) All covenants,
agreements, representations and warranties made by the Borrower and the
Subsidiary Guarantors herein and in the certificates or other instruments
prepared or delivered in connection with or pursuant to this Guaranty or any
other Loan Document shall be considered to have been relied upon by the
Administrative Agent and the other Guaranteed Parties and shall survive the
making by the Lenders of the Loans and the issuance of the Letters of Credit by
the L/C Issuer regardless of any investigation made by the Guaranteed Parties or
on their behalf, and shall continue in full force and effect as long as the
principal of or any accrued interest on any Loan or any other fee or amount
payable under this Guaranty or any other Loan Document is outstanding and unpaid
or the Commitments have not been terminated or any L/C Obligations have not been
Cash Collateralized in accordance with the provisions of the Credit Agreement.

          (b) In the event any one or more of the provisions contained in this
Guaranty or in any other Loan Document should be held invalid, illegal or
unenforceable in any respect, the validity, legality and enforceability of the
remaining provisions contained herein and therein shall not in any way be
affected or impaired thereby (it being understood that the invalidity of a
particular provision in a particular jurisdiction shall not in and of itself
affect the validity of such provision in any other jurisdiction). The parties
shall endeavor in good-faith negotiations to replace the invalid, illegal or
unenforceable provisions with valid provisions the economic effect of which
comes as close as possible to that of the invalid, illegal or unenforceable
provisions.

                                     - 6 -

<PAGE>

          Section 16. Counterparts. This Guaranty may be executed in
counterparts, each of which shall constitute an original, but all of which when
taken together shall constitute a single contract, and shall become effective as
provided in Section 11. Delivery of an executed signature page to this Guaranty
by facsimile transmission shall be as effective as delivery of a manually
executed counterpart of this Guaranty.

          Section 17. Rules of Interpretation. The rules of interpretation
specified in Section 1.02 of the Credit Agreement shall be applicable to this
Guaranty.

          Section 18. Jurisdiction; Consent to Service of Process. (a) Each
party hereto hereby irrevocably and unconditionally submits, for itself and its
property, to the nonexclusive jurisdiction of any New York State court or
federal court of the United States of America sitting in New York City, and any
appellate court from any thereof, in any action or proceeding arising out of or
relating to this Guaranty or the other Loan Documents, or for recognition or
enforcement of any judgment, and each of the parties hereto hereby irrevocably
and unconditionally agrees that all claims in respect of any such action or
proceeding may be heard and determined in such state court or, to the extent
permitted by law, in such federal court. Each of the parties hereto agrees that
a final judgment in any such action or proceeding shall be conclusive and may be
enforced in other jurisdictions by suit on the judgment or in any other manner
provided by law. Nothing in this Guaranty shall affect any right that the
Administrative Agent or any other Guaranteed Party may otherwise have to bring
any action or proceeding relating to this Guaranty or the other Loan Documents
against each Subsidiary Guarantor or its properties in the courts of any
jurisdiction.

          (b) Each party hereto hereby irrevocably and unconditionally waives,
to the fullest extent it may legally and effectively do so, any objection that
it may now or hereafter have to the laying of venue of any suit, action or
proceeding arising out of or relating to this Guaranty or the other Loan
Documents in any New York State or federal court. Each of the parties hereto
hereby irrevocably waives, to the fullest extent permitted by law, the defense
of an inconvenient forum to the maintenance of such action or proceeding in any
such court.

          (c) Each party to this Guaranty irrevocably consents to service of
process in the manner provided for notices in Section 14. Nothing in this
Guaranty will affect the right of any party to this Guaranty to serve process in
any other manner permitted by law.

          SECTION 19. WAIVER OF JURY TRIAL. EACH PARTY HERETO HEREBY WAIVES, TO
THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY RIGHT IT MAY HAVE TO A TRIAL
BY JURY IN RESPECT OF ANY LITIGATION DIRECTLY OR INDIRECTLY ARISING OUT OF,
UNDER OR IN CONNECTION WITH THIS GUARANTY OR THE OTHER LOAN DOCUMENTS. EACH
PARTY HERETO (A) CERTIFIES THAT NO REPRESENTATIVE, AGENT OR ATTORNEY OF ANY
OTHER PARTY HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PARTY WOULD
NOT, IN THE EVENT OF LITIGATION, SEEK TO ENFORCE THE FOREGOING WAIVER AND (B)
ACKNOWLEDGES THAT IT

                                     - 7 -

<PAGE>

AND THE OTHER PARTIES HERETO HAVE BEEN INDUCED TO ENTER INTO THIS GUARANTY AND
THE OTHER LOAN DOCUMENTS, AS APPLICABLE, BY, AMONG OTHER THINGS, THE MUTUAL
WAIVERS AND CERTIFICATIONS IN THIS SECTION 19.

          Section 20. Right of Setoff. If an Event of Default shall have
occurred and be continuing, each Guaranteed Party is hereby authorized at any
time and from time to time, to the fullest extent permitted by law, to set off
and apply any and all deposits (general or special, time or demand, provisional
or final and in whatever currency) at any time held and other Indebtedness at
any time owing by such Guaranteed Party to or for the credit or the account of
each Subsidiary Guarantor against any or all the obligations of such Subsidiary
Guarantor now or hereafter existing under this Guaranty and the other Loan
Documents held by such Guaranteed Party, irrespective of whether or not the
Administrative Agent or any Guaranteed Party shall have made any demand under
this Guaranty or any other Loan Document and although such obligations may be
contingent, unmatured, secured or unsecured or are owed to a branch or office of
such Guaranteed Party different from the branch or office holding such deposit
or obligated on such Indebtedness. Each Guaranteed Party agrees promptly to
notify such Subsidiary Guarantor and the Administrative Agent after any such
setoff and application; provided that failure to give such notice shall not
affect the validity of such setoff and application. The rights of each
Guaranteed Party under this Section 20 are in addition to other rights and
remedies (including other rights of setoff) which such Guaranteed Party may
have.

                            [signature pages follow]

                                     - 8 -
<PAGE>

          IN WITNESS WHEREOF, the parties hereto have duly executed this
Guaranty as of the day and year first above written.

                               COMPANY:

                               WRIGHT EXPRESS CORPORATION

                               By: /s/ Melissa D. Smith
                                   --------------------------------------------
                                   Name: Melissa D. Smith
                                   Title: Senior Vice President, Finance and
                                   Chief Financial Officer

                               SUBSIDIARY GUARANTOR:

                               WRIGHT EXPRESS FUELING SOLUTIONS, INC.

                               By: /s/ Michael E. Dubyak
                                   --------------------------------------------
                                   Name: Michael E. Dubyak
                                   Title: President

                                      S-1

<PAGE>

                               ADMINISTRATIVE AGENT:

                               BANK OF AMERICA, N.A., as Administrative
                               Agent

                               By: /s/ Kalens Herold
                                   --------------------------------------------
                                   Name: Kalens Herold
                                   Title: Assistant Vice President

                                      S-2

<PAGE>

                                                                       EXHIBIT A
                                                                 to the Guaranty

                                    [Form of]
                                JOINDER AGREEMENT

          Reference is made to that certain Credit Agreement dated as of May 22,
2007 (as in effect from time to time, the "Credit Agreement") among WRIGHT
EXPRESS CORPORATION, a Delaware corporation (the "Borrower"), each lender from
time to time party thereto, Bank of America, N.A., as Administrative Agent,
Swing Line Lender and L/C Issuer, SunTrust Bank, Inc., as Syndication Agent and
BMO Capital Markets, KeyBank National Association and TD Banknorth, N.A., as
Co-Documentation Agents. Capitalized terms used and not defined herein are used
with the meanings assigned to such terms in the Credit Agreement.

                                   WITNESSETH:

          WHEREAS, the Borrower and the Subsidiary Guarantors party thereto
entered into the Guaranty (the "Guaranty") dated as of May 22, 2007 with Bank of
America, N.A., as administrative agent (in such capacity, the "Administrative
Agent") in order to induce the Lenders to make the Loans to and the L/C Issuer
to issue Letters of Credit for the benefit of the Borrower and its Subsidiaries.

          WHEREAS, pursuant to Section 6.12 of the Credit Agreement, certain
Subsidiaries that were not in existence on the date of the Credit Agreement are
required to become a Subsidiary Guarantor under the Guaranty by executing a
joinder agreement.

          WHEREAS, the undersigned Subsidiary (the "New Subsidiary Guarantor")
is executing this joinder agreement (this "Joinder Agreement") to the Guaranty
in order to induce the Lenders to make additional Loans and to the L/C Issuer to
issue Letters of Credit, and as consideration for the Loans previously made.

          NOW, THEREFORE, the Administrative Agent, and the New Subsidiary
Guarantor hereby agree as follows:

          (a) Guarantee. In accordance with Section 6.12 of the Credit
     Agreement, the New Subsidiary Guarantor by its signature below becomes a
     Subsidiary Guarantor under the Guaranty with the same force and effect as
     if originally named therein as a Subsidiary Guarantor.

          (b) Representations and Warranties. The New Subsidiary Guarantor
     hereby (a) agrees to all the terms and provisions of the Guaranty
     applicable to it and its subsidiaries as a Guarantor thereunder and (b)
     represents and warrants that the representations and warranties made by it
     as a Subsidiary Guarantor thereunder are true and correct in all respects
     on and as of the date hereof. Each reference to a Subsidiary Guarantor in
     the Guaranty shall be deemed to include the New Subsidiary Guarantor.

                                      A-1

<PAGE>

          (c) Severability. In the event any one or more of the provisions
     contained in this Joinder Agreement should be held invalid, illegal or
     unenforceable in any respect, the validity, legality and enforceability of
     the remaining provisions contained herein shall not in any way be affected
     or impaired thereby (it being understood that the invalidity of a
     particular provision in a particular jurisdiction shall not in and of
     itself affect the validity of such provision in any other jurisdiction).
     The parties shall endeavor in good faith negotiations to replace the
     invalid, illegal or unenforceable provisions with valid provisions the
     economic effect of which comes as close as possible to that of the invalid,
     illegal or unenforceable provisions.

          (d) Counterparts. This Joinder Agreement may be executed in
     counterparts, each of which shall constitute an original. Delivery of an
     executed signature page to this Joinder Agreement by facsimile transmission
     shall be as effective as delivery of a manually executed counterpart of
     this Joinder Agreement.

          (e) No Waiver. Except as expressly supplemented hereby, the Guaranty
     shall remain in full force and effect.

          (f) Notices. All notices, requests and demands to or upon the New
     Subsidiary Guarantor, the Administrative Agent or any Lender shall be
     governed by the terms of Section 10.02 of the Credit Agreement.

          (g) Governing Law. THIS GUARANTY AND THE RIGHTS AND OBLIGATIONS OF THE
     PARTIES HEREUNDER SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH,
     THE LAW OF THE STATE OF NEW YORK.

                            [signature pages follow]

                                      A-2

<PAGE>

           IN WITNESS WHEREOF, the undersigned have caused this Joinder
Agreement to be duly executed and delivered by their duly authorized officers as
of the day and year first above written.

                             [NEW SUBSIDIARY GUARANTOR]

                             By: ____________________________
                                 Name:
                                 Title:

                             Address for Notices:

                                      A-3
<PAGE>

                             BANK OF AMERICA, N.A., as Administrative Agent

                             By:  ______________________________
                                  Name:
                                  Title:

                                      A-4

<PAGE>

                                   Schedule I

                               Address for Notices

SUBSIDIARY GUARANTORS

c/o Wright Express Corporation
97 Darling Avenue
South Portland, ME 04106
Attention: Melissa Smith, Senior Vice President, Finance
            and Chief Financial Officer
Telephone:  (207) 523-7643
Telecopier:  (207) 523-7797