QuickLinks -- Click here to rapidly navigate through this document

Exhibit 10.10

WASHINGTON MUTUAL, INC.

DEFERRED COMPENSATION PLAN

        The Deferred Compensation Plan for Directors and Certain Highly
Compensated Employees was initially adopted by Washington Mutual Savings Bank on
February 17, 1987, was amended and restated effective January 1, 1988 and was
subsequently amended and restated effective January 1, 1993. Sponsorship of the
Plan was transferred to Washington Mutual, Inc. in 1994 in connection with the
corporate reorganization pursuant to which Washington Mutual Savings Bank was
merged into Washington Mutual Bank and became a subsidiary of Washington
Mutual, Inc. The Plan was amended and restated in its entirety by Washington
Mutual, Inc., generally effective February 1, 1997 and was subsequently amended
and restated effective January 1, 2000. The Plan was again amended and restated
effective April 17, 2001.

        The Washington Mutual Deferred Compensation Plan for Certain Highly
Compensated Employees, which was initially adopted effective February 17, 1987,
was amended and restated effective January 1, 1997. Management has decided to
merge the Deferred Compensation Plan for Certain Highly Compensated Employees
with the Deferred Compensation Plan for Directors and Certain Highly Compensated
Employees effective as of November 1, 2002 and was restated at that time. The
Plan is hereby renamed the "Deferred Compensation Plan" and is amended and
restated effective July 20, 2004 as follows:

1.DEFINITIONS.

        1.1   "Account" means a separate bookkeeping account established for
each Participant on the books of the Company that employs the applicable
Participant for the purpose of recording amounts of Compensation deferred,
Restricted Stock Awards surrendered or Discretionary Company Contributions made
by or on behalf of such Participant, and income earned thereon, pursuant to the
provisions of the Plan.

        1.2   "Annual Bonus" means an annual bonus paid under the Leadership
Bonus Plan or any other plan hereafter adopted by the Company that provides
annual bonuses for executives and management. It does not include commissions or
other similar variable compensation, and does not include bonuses for services
for less than the full calendar year.

        1.3   "Board" means the Board of Directors of The Company.

        1.4   "Code" means the Internal Revenue Code of 1986, as it may be
amended or replaced from time to time.

        1.5   "Company" means Washington Mutual, Inc. ("The Company").

        1.6   "Compensation" means salary, Annual Bonus, quarterly or semiannual
bonuses, commissions, variable compensation, payments from designated deferred
bonus incentive plans and other direct cash compensation payable by an Employer
to an Eligible Employee for services rendered, and Directors' fees payable by
the Company to its Directors. The term "Compensation" shall not include
reimbursement for expenses incurred by the Eligible Employee, or contributions
to or benefits accrued under any Retirement Plan. In addition, the term
"Compensation" does not include Restricted Stock Awards.

        1.7   "Discretionary Company Contributions" has the meaning set forth in
Section 3.6.

        1.8   "Effective Date" means July 20, 2004, for purposes of this
amendment and restatement.

        1.9   "Eligible Employee" has the meaning set forth in Section 2.

        1.10 "Employer" means Washington Mutual, Inc., or any direct or indirect
subsidiary of Washington Mutual, Inc. With respect to any Participant or former
Participant, the term "Employer" means the

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

company by whom the Participant is currently employed, or was last employed in
the case of a former Participant.

        1.11 "ERISA" means the Employee Retirement Income Security Act of 1974,
as amended from time to time.

        1.12 "Human Resources Committee" means the Directors' Human Resources
Committee.

        1.13 "Nonqualified Stock Options" means those nonqualified stock options
of the Company awarded to a Participant pursuant to any plan adopted by the
Company that provides for stock option grants.

        1.14 "Participant" means any Eligible Employee who has elected to defer
Compensation under the Plan.

        1.15 "Plan" means this plan for the deferral of Compensation, as it may
be amended from time to time.

        1.16 "Plan Administration Committee" or "Committee" means such person or
persons appointed under the provisions of Section 7 to administer and interpret
the terms of the Plan.

        1.17 "Plan Year" means the 12-consecutive-month period commencing each
January 1 and ending each December 31.

        1.18 "Pre-Existing Plan" means the Plan as in effect prior to the
Effective Date.

        1.19 "Qualifying Gain" means the net whole shares accrued on behalf of a
Participant upon his or her exercise of Nonqualified Stock Options using the
stock-for-stock cashless payment method set forth in Section 3.1(c).

        1.20 "Qualifying Gain Account" means a separate bookkeeping account
established for the Participant on the books of each Employer that employs such
Participant for purposes of accounting for any Qualifying Gain deferred by such
Participant, and phantom dividend equivalent units earned thereon, pursuant to
the provisions of the Plan. Any Qualifying Gain that is deferred and held in
this account shall be converted to phantom stock units equal to the Qualifying
Gain. Any phantom dividend equivalent units credited to this account shall be
converted to phantom stock units in accordance with Section 4.3(c).

        1.21 "Retirement Plan" means any defined benefit or defined contribution
plan qualified under Section 401(a) of the Code, and which is sponsored by one
or more Employers.

        1.22 "Restricted Stock Award" means an award of stock of The Company
made to a Participant pursuant to any plan adopted by the Company that provides
for awards of restricted stock.

        1.23 "WM DC Plan for HCE's" means the Washington Mutual Deferred
Compensation Plan for Certain Highly Compensated Employees. Effective
November 1, 2002, this plan is terminated.    A "Former Participant" means a
participant in the Washington Mutual Deferred Compensation Plan for HCE's who
first became eligible to participate in this Plan on November 1, 2003.

2.ELIGIBILITY.

        2.1    Eligible Employees.    Eligible Employees include:

(a)Each Director of the Company;

(b)Each employee in salary levels 1-5; and

(c)Each "highly compensated" employee of any Employer who is determined (whether
individually or by class or category) by the Committee, in its discretion to be
eligible to

2

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

participate under the Plan. Effective April 1, 2005, only employees who are
expected to have Compensation in excess of $200,000 will be eligible to
participate for the Plan year.

        2.2    Inactive Participants.    When an Eligible Employee ceases to
meet the eligibility criteria, he will be ineligible to make any deferrals under
this Plan, and will become an "Inactive Participant." Inactive Participants will
be allowed to change their beneficiary designations and make changes to the
earning accrual method, but will otherwise not be treated as a Participant under
this Plan. Balances in the accounts of Inactive Participants will be distributed
based on previous elections with respect to those balances.

        2.3    Ineligible Employees.    The Committee reserves the right to
designate certain employees (whether individually or by class) ineligible to
participate under the Plan, in its absolute discretion.

        2.4    Errors.    If an employee is determined to be an Eligible
Employee based on a mistake of fact, he will immediately become an Ineligible
Employee and his account balance will be distributed to him as soon as
administrative feasible.

3.DEFERRAL ELECTION AND DISCRETIONARY COMPANY CONTRIBUTION.

        3.1    Election to Defer Compensation and Certain Gains.    

        (a)    Compensation.    Any Eligible Employee may elect to defer the
receipt of all or any portion of his or her Compensation for services to be
rendered in the immediately following period, as defined by the Committee. The
Committee may, in its discretion, establish separate elections for any component
of Compensation, including but not limited to, Annual Bonus, other bonus, and
distributions from deferred bonus or incentive plans.

        (b)    Restricted Stock.    Each Eligible Employee may elect to
surrender all or a portion of any Restricted Stock Award, in whole shares, in
exchange for a credit to such Eligible Employee's Account, determined as set
forth in Section 4.2(c), provided that such election must be made at least six
months before the date on which the restrictions with respect to the subject
Restricted Stock Award lapse.

        (c)    Gain From Exercise of Nonqualified Stock Options.    

        (i)    Each Eligible Employee may elect to defer all Qualifying Gain
derived from a specific grant of Nonqualified Stock Options in exchange for a
credit to such Eligible Employee's Qualifying Gain Account, in accordance with
Section 4.2(d), if (i) an irrevocable deferral election is completed and signed
by such Eligible Employee, (ii) such deferral election is delivered to and
accepted by the Committee at least six months before the date on which such
Eligible Employee elects to exercise Nonqualified Stock Options (the "Exercised
Options"), (iii) such Eligible Employee pays, through an attestation acceptable
to the Committee, the exercise price in shares of Company common stock that the
Participant owns and has owned continuously for the six-month period ending on
the date of exercise (the "Mature Shares"), and (iv) such Eligible Employee
complies with all other rules the Committee may establish from time to time. A
deferral of Qualifying Gain under this Section 3.1(c) shall be deemed to be
(A) a tender of Mature Shares in exchange for an equivalent number of shares
pursuant to the exercise of Nonqualified Stock Options and (B) a conversion of
the Participant's right to receive any additional shares related to the
Exercised Options into a right to receive deferred compensation pursuant to the
Plan. A deferral election under this Section 3.1(c) shall expire at any time
elected by a Participant therein and shall automatically be revoked upon a
Participant's termination of employment or in the event of a change in control
or at any other time determined by the Committee in its sole discretion.

3

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

        (ii)   The Plan governs the deferral of Qualifying Gain. The underlying
Nonqualified Stock Options are governed by the stock option plan under which
they were granted. No stock options or shares of The Company common stock are
authorized to be issued under the Plan.

        (d)    Performance Shares.    Each Eligible Employee may elect to
surrender all or a portion of any Performance Share Award, in whole shares, in
exchange for a credit to such Eligible Employee's Account, determined as set
forth in Section 4.2(f) provided that such election must be made at least six
months before the date on which the award is paid out.

        3.2    Limitation on Elections.    Notwithstanding anything in this
Section 3.1 to the contrary, any amount to be deferred under the Plan shall not
reduce the current Compensation of the Participant below the total amount that
is to be withheld from the Participant's Compensation pursuant to a requirement
of law or pursuant to an elected optional payroll deduction. In addition, the
Plan shall not be construed to determine or affect any Participant's entitlement
to any bonus. Accordingly, in the event that a Participant elects to defer a
percentage of any potential bonus that is not ultimately awarded, such election
shall be null and void.

        3.3    Effect of Termination on Election.    Notwithstanding anything in
this Section 3 to the contrary, upon termination of employment, a Participant is
no longer eligible to participate in the Plan, and accordingly any previous
elections to defer any amounts that relate to payments to be made after
employment has terminated shall be null and void.

        3.4    Timing, Form and Manner of Election.    The Plan Administration
Committee may, in its discretion, establish rules that govern the timing, form
and manner of election, provided that the Plan Administration Committee may not
change the requirement that elections pursuant to Section 3.1(b) and
Section 3.1(c) be made at least six months in advance. The Plan Administration
Committee may delegate its authority under this Section 3.3 to an individual or
committee, at its discretion. Any rules established under this section shall be
in writing and shall be communicated to Participants.

        3.5    Modification of Election.    With respect to elections to defer
all Compensation other than Annual Bonuses and other bonuses, a Participant's
election under Section 3.1 shall continue from calendar year to calendar year
until the election is terminated or the election is modified. The Committee may
establish rules governing the modification of an election, including the timing,
form and manner of such modifications.

        3.6    Discretionary Company Contribution.    In its sole discretion,
and for the purpose of attracting or retaining highly qualified employees, the
Human Resources Committee may credit an Eligible Employee's account with a
contribution known as a Discretionary Company Contribution. Any Discretionary
Company Contribution made on behalf of an Eligible Employee pursuant to this
Section 3.6 shall be credited to the Eligible Employee's Account as of a date
determined by the Human Resources Committee and may be subject to such other
terms and conditions, including provisions regarding vesting, that are set forth
in an individual agreement between the Participant and the Committee setting
forth such terms and conditions.

        3.7    Director Retainer.    The Governance Committee of the Board of
Directors may, in its sole discretion, credit a Director's account with a
Discretionary Company Contribution, and may attach special rules conditions that
apply to such contributions. Except as otherwise specified by the Governance
Committee, any such contributions shall be subject to the provisions of this
Plan.

4.ACCOUNTS.

        4.1    Separate Accounts.    The Committee shall establish a separate
Account for each Participant, to which it will credit each amount required to be
credited hereunder. The Account thus established shall be a bookkeeping Account,
and shall not grant to any Participant any security interest or other prior
right in any assets of the Company by reason of such credits.

4

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

        4.2    Timing of Credit.    Subject to Section 5.2(c), the Committee
shall credit to each Participant's Account:

        (a)   as of the end of each pay cycle, that portion of such
Participant's regular Compensation earned during the immediately preceding pay
period for which a deferral election under Section 3.1 is in effect.

        (b)   with respect to each deferral election under Section 3.1 that
defers any bonus, commission, variable compensation or other element of
Compensation that is not regular monthly compensation, the amount of the
deferral election as of the date the bonus, commission, variable compensation or
other Compensation, if any, would be paid by the Company to the Participant
absent an election to defer.

        (c)   with respect to any deferral election made by a Participant under
Section 3.1(b) (relating to restricted stock), the amount of the value of the
surrendered Restricted Stock Award as of the date the restrictions lapse1. The
value of such Restricted Stock Award shall be the number of shares of Restricted
Stock surrendered to the Company multiplied by the closing price of such shares
of stock as of the date the restrictions on such stock otherwise would have
lapsed pursuant to the terms of the Restricted Stock Award. For these purposes,
the closing price shall be the closing price of the common stock of The Company
on the New York Stock Exchange, or on such other national securities exchange or
national securities association on which such stock is then traded.

        (d)   with respect to any deferral election made under Section 3.1(c)
(relating to Qualifying Gain deferral), to the Participant's Qualifying Gain
Account a number of phantom stock units equal to the value of deferred
Qualifying Gain divided by the closing price of The Company common stock on the
day preceding the effective date of the Qualifying Gain deferral. For these
purposes, the closing price shall be the closing price of the common stock of
the Company on the New York Stock Exchange, or on such other national securities
exchange or national securities association on which such stock is then traded.

        (e)   with respect to any Discretionary Company Contribution made with
respect to a Participant under Section 3.6, the Committee shall credit to the
Participant the amount of each contribution as of the date specified by the
Human Resources Committee.

        (f)    with respect to any deferral election made under Section 3.1(d)
(relating to Performance Shares), the amount of the value of the surrendered
Performance Share Award as of the date the Award is approved by the Human
Resources Committee. The value of such Performance Shares Award shall be the
value of the approved payout.

        4.3    Additional Credits.    

        (a)   Each Participant's Account shall be credited with additional
amounts pursuant to the "Interest Method" set forth in Section 4.3(b)(1), the
"Stock Fund Method" set forth in Section 4.3(b)(2), or effective April 1, 2004,
the "Index Fund Method" set forth in Section 4.3(b)(3). The method of crediting
shall be elected by the Participant, the timing, manner and form of which shall
be subject to rules established by the Plan Administration Committee, provided
that amounts credited to a Participant's Qualifying Gain Account shall not be
subject to such election. The Plan Administration Committee may also establish
rules that limit or restrict such elections and may establish rules for
modifying such elections from time to time. Portions of an Account for which
there is no effective election shall be credited pursuant to Section 4.3(b)(1).

        (b)   (1) With respect to the portion of a Participant's Account
credited pursuant to the Interest Method, the Committee shall credit to the
Participant's Account interest on the balance of

5

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

such Account subject to the Interest Method at the interest rate in effect the
Plan Year, compounded on a daily basis. The applicable interest rate shall be
determined as follows:

        As of December 1 of each year, commencing with the Effective Date, the
Committee, in its sole discretion, will establish the applicable interest rate
for the following Plan Year by reference to the interest rate that the Committee
determines could be applicable as of such date to any unsecured junior debt
offering by Washington Mutual Bank or by a comparable financial institution or
public corporation. Such determination will be made by the Committee, which
shall request an estimate of such debt offering interest rate from at least one
nationally recognized investment banking firm. The interest rate so determined
will be set forth in writing and kept with the Plan records.

        (2)   With respect to the portion of a Participant's Account credited
pursuant to the Stock Fund Method, the Committee shall credit or debit such
Account to reflect the rate of return that would have been earned on such
portion of the Participant's Account as if such portion had been invested in
whole or partial shares of the Company's common stock and received any dividends
paid on such common stock.

        (3)   Effective April 1, 2004, with respect to the portion of a
Participant's Account credited pursuant to the Index Fund Method, the Committee
shall credit or debit such Account to reflect the rate of return that would have
been earned on such portion of the Participant's Account as if such portion had
been invested in the funds selected by the Participant from the funds listed in
Appendix A, as amended from time to time.

        (c)   Each Participant's Qualifying Gain Account shall be credited with
phantom dividend equivalent units equal to the product of the dividend paid on a
share of The Company common stock multiplied by the number of phantom stock
units held in the Participant's Qualifying Gain Account on the record date for
the cash dividend. Phantom dividend equivalent units credited to each
Participant's Qualifying Gain Account shall be used to "purchase" additional
phantom stock units for such Account at a price equal to the closing price of
the the Company common stock on the date such phantom dividend equivalent units
are so credited. No fractional phantom stock units shall be credited based on
this "purchase."

        (d)   Notwithstanding any provisions in this Section 4.3 to the
contrary, effective November 1, 2002, upon termination of employment, a
Participant shall receive additional credits exclusively under Section 4.3(b)(1)
(the "Interest Method") regardless of any election made by the Participant.

5.PAYMENT OF ACCOUNT BALANCE.

        5.1    Payment Method.    The Company shall pay the Participant's
Account balance under the Plan to such Participant in accordance with the
payment option designated by the Participant pursuant to Section 5.3. In the
event of the death of the Participant prior to payment of the entire Account
balance, payment shall be made to such Participant's beneficiary or
beneficiaries designated under Section 6 in accordance with the payment method
designated by the Participant pursuant to this Section 5, or in accordance with
any accelerated method (including lump sum) as the Plan Administration Committee
shall determine in its sole discretion.

        5.2    Withholding and Offset.    Any payment or other distribution of
benefits under the Plan may be reduced or offset by:

        (a)   Any amount required to be withheld by the Company under any
applicable law, rule, regulation, order or other requirement, now or hereafter
in effect, of any governmental authority.

        (b)   Any outstanding debt, obligation or other liability representing
an amount owing to the Company.

6

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

        (c)   Any tax withholding required with respect to Compensation deferred
hereunder, a deferral credit with respect to surrendered restricted stock or a
Discretionary Company Contribution, if and only if nondeferred Compensation is
insufficient for such required withholding.

        5.3    Election of Payment Options.    At the time of making an election
under Section 3.1 or within the prescribed election period after receiving a
credit for a Discretionary Company Contribution under Section 3.6 or a Director
Retainer under Section 3.7, the Participant shall specify the payment method and
timing in accordance with the following provisions:

        (a)    Payment Methods.    Participant may elect either:

        (i)    Payment of the entire Account balance attributable to such
deferral or credit in a single lump sum payment. If a Participant fails to make
a payment method election, any balances attributable to those amount shall be
paid out as a single lump sum. In addition, if at the date selected by the
Participant for commencement of payment, a Participant's account balance is less
than $100,000, the entire balance will be distributed to the Participant in a
lump sum regardless of any election made by the Participant.

        (ii)   Payment of the Account balance attributable to such deferral or
credit in quarterly installments over a period of up to 10 years, with each
installment to be an amount equal to the Account balance as of the date of
payment divided by the number of installments remaining to be paid, including
the current installment. This section shall not apply to Participants whose
Account balance does not exceed $100,000 as of the date on which installments
would otherwise begin, and such balances shall be paid in accordance with
Section 5.3(a)(i) notwithstanding any election to the contrary. Only the
Participant's Account balance when payments commence shall be used to determine
installment payments.

        (b)    Payment Commencement.    Payments will commence at the time
elected by the Participant at the time of making a deferral election under
Section 3.1 or within a prescribed time after being credited with a
Discretionary Company Contribution under Section 3.6 or a Director Retainer
under Section 3.7. Such election shall be irrevocable. The Committee, in its
discretion, may establish rules governing commencement of payment elections,
including but not limited to rules that restrict the number of dates a
Participant may choose, whether different dates may be selected for different
deferrals or contributions, the extent to which different dates will be
accepted, and whether events may be elected or specific dates are required. The
payment commencement date may not be modified. If no election is made, the
default commencement date is the date of the Participant terminates his
employment.

        (c)   Payment options elected under Section 5.3(a) may be modified,
subject to rules the Plan Administration Committee may, in its discretion,
establish, provided that in no case will a Participant be permitted to modify a
payment option election less than six months prior to the payment commencement
date.

        (d)   All payments from a Participant's Account shall be in cash. All
payments from a Participant's Qualifying Gain Account shall be in the form of
whole shares of the Company common stock equal to the number of phantom stock
units held in such Account, rounded down to the nearest whole unit, such shares
to be paid from a plan that provides for awards of shares of Company common
stock.

        5.4    Payment for Unforeseeable Emergency.    A Participant shall not
be entitled to withdraw any portion of the balance of his or her Account except
that, in cases of an unforeseeable emergency, the Plan Administration Committee
may authorize, on a uniform and nondiscriminatory basis and taking into account
other resources reasonably available to the Participant, payment of so much of
the Participant's Account as is required to meet the need created by the
emergency.

7

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

        (a)   For the purposes hereof, an "unforeseeable emergency" exists if
the distribution is for one of the following:

        (i)    Expenses for medical care described in Section 213(d) of the Code
previously incurred by the Participant, his spouse, or his dependents (as
defined in Code Section 152) or necessary for these persons to obtain medical
care described in Section 213(d); or

        (ii)   Payments necessary to prevent the eviction of the Participant
from his principal residence or foreclosure on the mortgage on that residence.

        (iii)  Any immediate and heavy financial needs as deemed by IRS.

        (b)   In addition to the foregoing, to be eligible for distribution
under this Section 5.4, a Participant:

        (i)    may only receive an amount necessary to provide for the immediate
and heavy financial need under Section 5.4(a); and

        (ii)   must have exhausted all other financial resources available to
the Participant under any of the Company's benefit plans, including but not
limited to loans and hardship distributions from the WaMu Savings Plan and sale
of shares of Company stock received through one of the Company's equity plans
(or exercise of options received under those plans).

        (c)   A Participant will be deemed to have met the requirements of
Section 5.4(a) if the plan administrator for the WaMu Savings Plan has
determined that the Participant is eligible for a hardship withdrawal under the
WaMu Savings Plan, provided that the reason for the distribution is one of the
three reasons set forth in Section 5.4(a). If the Participant is not a
participant in the WaMu Savings Plan, the Committee will determine whether or
not the Participant is eligible for a distribution under this Section.

        (d)   Any Participant who receives a payment under this Section 5.4
shall be ineligible to defer any amounts under Section 3 for a period of six
months, and any election, whenever made to defer any such amounts shall be null
and void.

        5.5    Limitation on Liability.    The Company's maximum liability to
make payments hereunder is limited to the amount of the Participant's Account
(including the interest thereon pursuant to Section 4.3).

        5.6    Upon Death of Participant.    Upon the death of a Participant,
his entire balance will be paid to his Beneficiary, as determined under
Section 6, in a lump sum as soon as administratively feasible, provided that the
balance in his Accounts immediately after his death is less than $100,000. If
his balance immediately after his death is $100,000 or more, the balance will be
paid in three annual installments.

6.BENEFICIARY DESIGNATION.

        6.1    Designation of Beneficiary.    A Participant may designate a
person or persons as the Participant's beneficiary or beneficiaries (both
primary as well as secondary) to whom payment under the Plan shall be made in
the event of the Participant's death prior to complete distribution of such
Participant's Account balance under the Plan. The Plan Administration Committee,
in its discretion, may establish rules governing the timing, manner and form of
beneficiary designations. If one or more designated beneficiaries survives the
Participant, payment will be made in accordance with the beneficiary designation
on file. If all of the designated beneficiaries fail to survive the Participant,
payment will be made in accordance with Section 6.3.

        6.2    Filing New Designation.    The filing of a new beneficiary
designation form will cancel all beneficiary designations previously filed.

8

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

        6.3    Failure to Designate.    If a Participant fails to designate a
beneficiary as provided above, or if all designated beneficiaries predecease the
Participant then, the Committee shall direct the distribution of such benefits
to the Participant's estate. The Plan Administration Committee may, in its
discretion direct payment to another individual or entity if there is no estate
or under other circumstances that would make payment to the estate impossible,
impractical or costly.

        6.4    Death of Beneficiary.    At the death of the beneficiary who is
entitled to receive payments hereunder, the balance (if any) then remaining in
the Participant's Account shall be paid in a lump sum to the beneficiary's
estate. Such payment shall completely discharge the Company's obligations under
the Plan.

        6.5    Change of Beneficiary.    Notwithstanding any other provision of
the Plan, any beneficiary designation may be changed by a Participant at any
time by the written filing of such change on a form prescribed by the Committee.

        6.6    Beneficiary Designations Under Other Plan Recognized.    Any
beneficiary designation properly executed under the terms of the WM DC Plan for
HCEs shall be given full force and effect under this Plan.

7.ADMINISTRATION OF THE PLAN.

        7.1    Appointment.    The Plan Administration Committee has been
appointed by the Company to administer the Plan and serves in such capacity at
the pleasure of the Board.. The Board may remove the Committee or appoint a
successor committee at any time. If the Plan Administration Committee ceases to
exist or is removed without the appointment of a replacement committee, the
Company shall function as the Committee.

        7.2    Term.    Each member of the Committee shall serve until his or
her successor is appointed. Any member of the Committee may be removed by the
Company, with or without cause, which shall have the power to fill any vacancy
which may occur. A member may resign upon written notice to the Company.

        7.3    Compensation.    The members of the Committee shall serve without
compensation for services as such, but the Company shall pay all expenses of the
members of the Committee.

        7.4    Powers of Plan Administration Committee.    The Committee shall
have full and absolute discretion in the exercise of its powers hereunder. All
exercises of power by the Committee hereunder shall be final, conclusive and
binding on all interested parties, unless found by a court of competent
jurisdiction, in a final judgment that is no longer subject to review or appeal,
to be arbitrary and capricious. In addition to the power otherwise enumerated
herein, the Committee shall have the following specific authority:

        (a)   To direct the administration of the Plan in accordance with the
provisions herein set forth;

        (b)   To adopt rules of procedure and regulations necessary for the
administration of the Plan that are not inconsistent with the terms of the Plan;

        (c)   To interpret and construe the provisions of the Plan and determine
all questions with respect to rights of Employees, Participants, and
Beneficiaries under the Plan, including but not limited to rights of eligibility
of an Employee to participate in the Plan, the value of a Participant's
Accounts, and the nonforfeitable percentage of each Participant's Accounts;

        (d)   To interpret and enforce the terms of the Plan and the rules and
regulations it adopts;

        (e)   To review and render decisions with respect to a claim for, (or
denial of a claim for) a benefit under the Plan;

9

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

        (f)    To furnish the Employer with information that the Employer may
require for tax or other purposes;

        (g)   To engage the service of counsel (who may, if appropriate, be
counsel for the Employer) and agents whom it may deem advisable to assist it
with the performance of its duties;

        (h)   To prescribe procedures to be followed by Participants in
obtaining benefits

        (i)    To receive from the Employer and from Employees such information
as shall be necessary for the proper administration of the Plan;

        (j)    To maintain, or cause to be maintained, separate Accounts in the
name of each Participant;

        (k)   To select a secretary, who need not be a member of the Committee:
and

        (l)    To interpret and construe the Plan; and

        (m)  To amend the Plan, but only for the following purposes:

        (i)    changes in the laws or regulations related to this Plan;

        (ii)   to clarify any provisions in the Plan or correct any errors in
the document;

        (iii)  to simplify administration or for administrative convenience; and

        (iv)  for any other reason, provided that no such amendment shall
materially increase the Company's liability or potential liability under this
Plan.

        7.5    Manner of Action.    The decision of a majority of the members of
the Plan Administration Committee appointed and qualified shall control. In case
of a vacancy in the membership of the Committee, the remaining members may
exercise any and all of the powers, authorities, duties, and discretion
conferred upon the Committee. The Committee may, but need not, call or hold
formal meetings. Any decision made or action taken pursuant to written approval
of a majority of the then members shall be sufficient. The Committee shall
maintain adequate records of its decisions.

        7.6    Authorized Representative.    The Committee may authorize any one
of its members, or its secretary, to sign on its behalf any notices, directions,
applications, certificates, consents, approvals, waivers, letters, or other
documents.

        7.7    Interested Member.    No member of the Committee may decide or
determine any matter concerning the distribution, nature, or method of
settlement of his own benefits under the Plan unless there is only one person
acting alone in the capacity as the Committee.

        7.8    Indemnity.    The Company shall indemnify and save harmless the
Committee, and its members, and each of them, from and against any and all loss
resulting from liability to which the Committee, or its members, may be
subjected by reason of any act, conduct, or inaction (except willful or reckless
misconduct), in their official capacities in the administration of the Plan,
including all expenses reasonably incurred in their defense, in case the Company
fails to provide such defense.

8.CLAIMS PROCEDURE.

        8.1    Claims Procedure.    The Plan Administrator is responsible for
evaluating all claims for reimbursement under the Plan. The Plan Administrator
will decide the claim within a reasonable time not longer than ninety (90) days
after it is received. This time period may be extended for an additional ninety
(90) days for matters beyond the control of the Plan Administrator, including
cases where a claim is incomplete. The Participant will receive written notice
of any extension, including the reasons for the extension and information on the
date by which a decision by the Administrator is expected to be made.

10

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

        8.2    Benefit Denial.    If the Plan Administrator denies a
Participant's claim, in whole or in part, the Participant will be furnished with
a written notice of adverse benefit determination setting forth:

        a)    The specific reasons or reasons for the denial;

        b)    Reference to the specific Plan provision or provisions on which
the denial is based;

        c)     A description of any additional material or information necessary
for the Participant to complete the claim and an explanation of why such
material or information is necessary; and

        d)    Appropriate information as to the steps to be taken if the
Participant wishes to appeal the Plan Administrator's determination, including
the right to submit written comments and have them considered, the right to
review (on request and at no charge) relevant documents and other information,
and the right to file suit under ERISA with respect to any adverse determination
after appeal of the claim.

        For purposes of this Section 8, a "claim" means a written request for
Plan benefits filed with the Plan Administrator. A mere inquiry or request for
information shall not constitute a claim.

        8.3    Appealing Denied Claims.    If a Participant's claim is denied in
whole or in part, the Participant may appeal to the Plan Administrator for a
review of the denied claim. The appeal must be made in writing within sixty
(60) days of the Plan administrator's initial notice of adverse benefit
determination, or a Participant will lose the right to appeal the denial.
Failure to make a timely appeal will result in forfeiture of the right to file
suit in court, as a Participant will have failed to exhaust internal
administrative appeal rights, which is generally a prerequisite to bringing
suit.

        The written appeal should state the reasons that the Participant
believes the claim should not have been denied and should cite specific
provisions of the Plan that support that claim. It should include any additional
facts and/or documents that support the claim. The Participant may also ask
additional questions and make written comments, and may review (on request and
at no charge) documents and other information relevant to the appeal. The Plan
Administrator will review all written comment submitted with the appeal.

        8.4    Review Procedure.    The Plan Administrator will review and
decide the appeal within a reasonable time not longer than sixty (60) days after
it is submitted and will notify a Participant of its decision in writing. The
individual who decides the appeal will not be the same individual who decided
the initial claim denial and will not be that individual's subordinate. If the
decision on appeal affirms the initial denial of the claim, the Participant will
be furnished with a notice of adverse benefit determination on review setting
forth:

        a)    The specific reason(s) for the denial;

        b)    The specific Plan provision(s) on which the decision is based;

        c)     A statement of the right to review (on request and at no charge)
relevant documents and other information;

        d)    If the Plan Administrator relied on an "internal rule, guideline,
protocol, or other similar criterion" in making the decision, a description of
the specific rule, guideline, protocol, or other similar criterion or a
statement that such a rule, guideline, protocol, or other similar criterion was
relied on and that a copy of such rule, guideline, protocol, or other criterion
will be provided free of charge to you upon request"; and

        e)    A settlement of your right to bring suit under ERISA § 502(a).

11

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

9.AMENDMENT AND TERMINATION OF PLAN.

        9.1    Amendment.    The Human Resources Committee may at any time amend
the Plan, provided that no amendment shall deny or reduce any amounts previously
credited to any Participant's Account. The Plan Administration Committee may
amend the Plan for the limited purposes set forth in Section 7.4(m).

        9.2    Termination.    

        (a)   The Human Resources Committee may at any time terminate the Plan,
if in its judgment the continuance of the Plan, or the tax, accounting or other
effects thereof, would not be in the best interest of the Company.

        (b)   Upon any termination of the Plan under this Section 9.2, the
Participant will be deemed to have withdrawn from the Plan as of the date of
such termination, the remaining deferred Compensation for the balance of the
calendar year shall prospectively cease to be deferred for such calendar year,
and the Company will pay to the Participant the balance in the Participant's
Account at such times and pursuant to such terms and conditions as the Human
Resources Committee in its sole discretion shall determine.

10.MISCELLANEOUS.

        10.1    Unsecured General Creditor; Unfunded Plan.    A Participant and
such Participant's beneficiaries, heirs, successors and assigns shall have no
legal or equitable rights, interest or claims in any property or assets of the
Company. Such assets of the Company shall not be held under any trust for the
benefit of a Participant, or such Participant's beneficiaries, heirs, successors
or assigns, or held in any way as collateral security for the fulfillment of the
obligations of the Company under the Plan. Any and all assets of the Company
shall be, and remain, the general, unpledged, unrestricted assets of the
Company. The Company's obligation hereunder shall be merely that of an unfunded
and unsecured promise of the Company to pay money in the future. It is the
intention of the parties hereto that the Plan be unfunded for tax purposes and
for purposes of Title I of ERISA.

        10.2    Plan Administrator.    With respect to ERISA, the Human
Resources Committee shall be the plan administrator and named fiduciary as to
the Plan and the corporate secretary of the Company shall be the agent for
purposes of receiving legal process.

        10.3    No Right to Employment.    The Plan shall not confer upon any
person the right to be retained in the employ of the Company, interfere with the
right of the Company to discharge or otherwise deal with any person without
regard to the existence of the Plan or otherwise be interpreted or construed as
creating or modifying any employment or other contract between the Company and
any person.

        10.4    Alienation.    No right, interest or benefit under the Plan
shall be subject in any manner to anticipation, alienation, sale, transfer,
assignment, pledge, security interest, encumbrance, charge, execution,
attachment, garnishment or legal process by the creditors of the Participant or
the Participant's beneficiary, and any attempt to do so shall be void, provided
that the Plan Administration Committee may, in its discretion, adopt rules
governing distributions to former spouses pursuant to court order in the case of
dissolution.

        10.5    Information.    Participants and their beneficiaries under the
Plan shall provide such authorizations, elections, designations and other
information as the Committee shall deem necessary for the proper administration
of the Plan. All such authorizations, elections, designations and other
information shall be in form approved by the Committee. The Committee shall not
be obligated to determine the accuracy or authenticity of any information
provided by any Participant or beneficiary under the Plan and any payment or
other distribution of benefits based thereon shall be binding on

12

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

such person, or on anyone claiming by, through or under such person, and shall
completely discharge any liability under the Plan to the extent of any payment
made.

        10.6    Headings.    Headings of sections and paragraphs of the Plan are
inserted for convenience of reference only and shall not constitute a part of
the Plan.

        10.7    Applicable Law.    The Plan shall be interpreted, construed and
enforced in accordance with the laws of the State of Washington, except insofar
as state law has been preempted by ERISA.

        10.8    Validity.    In the event any provision of the Plan is held
invalid, void or unenforceable, the same shall not affect, in any respect
whatsoever, the remainder of the Plan.

        10.9    Terminology.    Except when otherwise required by the context,
any masculine terminology in this document shall include the feminine, and any
singular terminology shall include the plural.

13

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

        IN WITNESS WHEREOF, the Company has caused the Plan to be executed on
this      day of           , 2004, but to be effective as of the Effective Date.

    WASHINGTON MUTUAL, INC.   
          
 
 
By:
    

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

 
 
Its:
    

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

14

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

Appendix A
Index Fund Method Choices

Effective April 1, 2004, the following funds shall be available for selection by
Participants under the Index Fund Method in Section 4.3(b)(3).

•Vanguard Institutional Index Fund (ticker symbol VIIIX)

•Vanguard Small-Cap Index Fund (ticker symbol VSCIX)

•Vanguard Developed Markets Index Fund (ticker symbol VDMIX)

15

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

QuickLinks

Exhibit 10.10

WASHINGTON MUTUAL, INC. DEFERRED COMPENSATION PLAN