<PAGE>   1

                     WASHINGTON MUTUAL FINANCE CORPORATION

                                       AND

                        THE BANK OF NEW YORK, AS TRUSTEE

                           --------------------------

                          Subordinated Debt Securities

                                    Indenture

                           ---------------------------

                          Dated as of _________, 200_



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        INDENTURE, dated as of _, 200_ (the "Indenture"), between
WASHINGTON MUTUAL FINANCE CORPORATION, a corporation duly organized and existing
under the laws of the State of Delaware (herein called the "Company"), having
its principal offices at 8900 Grand Oak Circle, Tampa, Florida 33637-1050, and
THE BANK OF NEW YORK, a New York banking corporation, as Trustee (herein called
the "Trustee").

                             RECITALS OF THE COMPANY

        The Company has duly authorized the execution and delivery of this
Indenture to provide for the issuance from time to time of its subordinated and
unsecured debentures, notes or other obligations for money so borrowed (herein
called the "Securities"), to be issued in one or more series as in this
Indenture provided.

        All things necessary to make this Indenture a valid agreement of the
Company, in accordance with its terms, have been done.

                   NOW, THEREFORE, THIS INDENTURE WITNESSETH:

        For and in consideration of the premises and the purchase of the
Securities by the Holders thereof, it is mutually covenanted and agreed, for the
equal and proportionate benefit of all Holders of the Securities or of any
series thereof, as follows:

PARAGRAPH A. INCORPORATION BY REFERENCE

        Articles I through XIV of the Washington Mutual Finance Corporation.
Standard Multiple-Series Indenture Provisions dated as of June __, 1999 (herein
called the "Standard Provisions") , a copy of which is attached hereto as Annex
"A", are hereby incorporated herein by reference with the same force and effect
as though fully set out herein.

PARAGRAPH B. ADDITIONAL PROVISIONS

        1.     Section 1.11 of the Standard Provisions is hereby amended by
inserting ", holders of Senior Debt" after the word "hereunder" on the third
line thereof.

        2.     Section 2.2 of the Standard Provisions is hereby amended by
deleting the words "[full name of Trustee] " and inserting the words "The Bank
of New York."

        3.     Section 1.5, subsection (b), of the Standard Provisions is hereby
amended by deleting the words "the address of its principal office specified in
the first paragraph of this instrument" and inserting the words 1201 Third
Avenue, Suite 1500, Seattle, Washington 98101, Attention: Executive Vice
President and General Counsel."

        4.     Section 6.14 of the Standard Provisions is hereby amended by
deleting the words "[full name of Trustee]" and inserting the words "The Bank
of New York."

        5.     The following provision, which constitutes part of this
Indenture, is numbered to conform with the format of the Standard Provisions.



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               Section 6.15. Corporate Trust Office. At the date of this
        Indenture, the Corporate Trust Office of the Trustee is located at 101
        Barclay Street, New York, New York 10286

        IN WITNESS WHEREOF, the parties hereto have caused this Indenture to be
duly executed, and their respective corporate seals to be hereunto affixed and
attested, all as of the day and year first above written.

                                       WASHINGTON MUTUAL FINANCE CORPORATION



                                       By
                                          --------------------------------------
                                          Authorized Signatory



[SEAL]

Attest




------------------------------
Authorized Signatory


                                       THE BANK OF NEW YORK,
                                       as Trustee


                                       By
                                          --------------------------------------
                                          Title: Authorized Signatory

[SEAL]

Attest



-------------------------------
Title: Authorized Signatory




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STATE OF WASHINGTON  )
                     ) ss
COUNTY OF KING       )

        On the _th day of _______ 200_, before me personally came ___________
________ to me known, who, being by me duly sworn, did depose and say that
he/she is ________________ of WASHINGTON MUTUAL FINANCE CORPORATION, one of the
corporations described in and which executed the foregoing instrument; that he
knows the seal of said corporation; that the seal affixed to said instrument is
such corporate seal; that it was so affixed by authority of the Board of
Directors of said corporation, and that he/she signed his/her name thereto by
like authority.




                                          --------------------------------------
                                          Notary Public











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        IN WITNESS WHEREOF, the parties hereto have caused this Indenture to be
duly executed, and their respective corporate seals to be hereunto affixed and
attested, all as of the day and year first above written.

                                       WASHINGTON MUTUAL FINANCE CORPORATION



                                       By:
                                           -------------------------------------
                                           Authorized Signatory



[SEAL]

Attest




------------------------------
Authorized Signatory


                                       THE BANK OF NEW YORK,
                                       as Trustee


                                       By
                                          --------------------------------------
                                          Title: Authorized Signatory

[SEAL]

Attest



------------------------------
Title: Authorized Signatory




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STATE OF NEW YORK          )
                           ) ss
COUNTY OF NEW YORK         )

        On the _th day of _______ 200_, before me personally came a __________
________ to me known, who, being by me duly sworn, did depose and say that
he/she is ______________ of THE BANK OF NEW YORK, one of the corporations
described in and which executed the foregoing instrument; that he/she knows the
seal of said corporation; that the seal affixed to said instrument is such
corporate seal; that it was so affixed by authority of the Board of Directors of
said corporation, and that he/she signed his/her name thereto by like authority.




                                          --------------------------------------
                                          Notary Public













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