<PAGE>

                                                                    EXHIBIT 4.12

                               GUARANTEE AGREEMENT

                              BLUE VALLEY BAN CORP

                           Dated as of April 10, 2003

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                                TABLE OF CONTENTS

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                                    ARTICLE I
                         DEFINITIONS AND INTERPRETATION

Section 1.1.  Definitions and Interpretation ..............................    1

                                   ARTICLE II
               POWERS, DUTIES AND RIGHTS OF THE GUARANTEE TRUSTEE

Section 2.1.  Powers and Duties of the Guarantee Trustee...................    4
Section 2.2.  Certain Rights of the Guarantee Trustee......................    5
Section 2.3.  Not Responsible for Recitals or Issuance of Guarantee........    7
Section 2.4.  Events of Default; Waiver....................................    7
Section 2.5.  Events of Default; Notice....................................    8

                                   ARTICLE III
                              THE GUARANTEE TRUSTEE

Section 3.1.  The Guarantee Trustee; Eligibility                               8
Section 3.2.  Appointment, Removal and Resignation of the Guarantee Trustee    9

                                   ARTICLE IV
                                    GUARANTEE

Section 4.1.  Guarantee.....................................................   9
Section 4.2.  Waiver of Notice and Demand .............................. ...  10
Section 4.3.  Obligations Not Affected......................................  10
Section 4.4.  Rights of Holders.............................................  11
Section 4.5.  Guarantee of Payment..........................................  11
Section 4.6.  Subrogation...................................................  11
Section 4.7.  Independent Obligations.......................................  11
Section 4.8.  Enforcement...................................................  12

                                    ARTICLE V
                    LIMITATION OF TRANSACTIONS; SUBORDINATION

Section 5.1.  Limitation of Transactions....................................  12
Section 5.2.  Ranking.......................................................  13

                                   ARTICLE VI
                                   TERMINATION

Section 6.1.  Termination...................................................  13

                                   ARTICLE VII
                                 INDEMNIFICATION

Section 7.1.  Exculpation...................................................  13
Section 7.2.  Indemnification...............................................  14
Section 7.3.  Compensation: Reimbursement of Expenses.......................  15
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                                TABLE OF CONTENTS
                                   (continued)

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                                  ARTICLE VIII
                                  MISCELLANEOUS

Section 8.1.  Successors and Assigns........................................  15
Section 8.2.  Amendments....................................................  15
Section 8.3.  Notices.......................................................  16
Section 8.4.  Benefit.......................................................  16
Section 8.5.  Governing Law.................................................  17
Section 8.6.  Counterparts..................................................  17
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                                       ii

<PAGE>

                               GUARANTEE AGREEMENT

             This GUARANTEE AGREEMENT (the "Guarantee"), dated as of April 10,
2003, is executed and delivered by Blue Valley Ban Corp, a bank holding company
incorporated in Kansas (the "Guarantor"), and Wilmington Trust Company, a
Delaware banking corporation, as trustee (the "Guarantee Trustee"), for the
benefit of the Holders (as defined herein) from time to time of the Capital
Securities (as defined herein) of BVBC Capital Trust II, a Delaware statutory
trust (the "Issuer").

             WHEREAS, pursuant to an Amended and Restated Declaration of Trust
(the "Declaration"), dated as of April 10, 2003, among the trustees named
therein of the Issuer, Blue Valley Ban Corp, as sponsor, and the Holders from
time to time of undivided beneficial interests in the assets of the Issuer, the
Issuer is issuing on the date hereof securities, having an aggregate liquidation
amount of up to $7,500,000, designated the Floating Rate MMCapS(SM) (the
"Capital Securities"); and

             WHEREAS, as incentive for the Holders to purchase the Capital
Securities, the Guarantor desires irrevocably and unconditionally to agree, to
the extent set forth in this Guarantee, to pay to the Holders of Capital
Securities the Guarantee Payments (as defined herein) and to make certain other
payments on the terms and conditions set forth herein.

             NOW, THEREFORE, in consideration of the purchase by each Holder of
the Capital Securities, which purchase the Guarantor hereby agrees shall benefit
the Guarantor, the Guarantor executes and delivers this Guarantee for the
benefit of the Holders.

                                    ARTICLE I
                         DEFINITIONS AND INTERPRETATION

SECTION 1.1. Definitions and Interpretation.

In this Guarantee, unless the context otherwise requires:

             (a)      capitalized terms used in this Guarantee but not defined
in the preamble above have the respective meanings assigned to them in this
Section 1.1;

             (b)      a term defined anywhere in this Guarantee has the same
meaning throughout;

             (c)      all references to "the Guarantee" or "this Guarantee" are
to this Guarantee as modified, supplemented or amended from time to time;

             (d)      all references in this Guarantee to Articles and Sections
are to Articles and Sections of this Guarantee, unless otherwise specified;

             (e)      terms defined in the Declaration as of the date of
execution of this Guarantee have the same meanings when used in this Guarantee,
unless otherwise defined in this Guarantee or unless the context otherwise
requires; and

<PAGE>

                  (f)      a reference to the singular includes the plural and
vice versa.

                  "Beneficiaries" means any Person to whom the Issuer is or
hereafter becomes indebted or liable.

                  "Corporate Trust Office" means the office of the Guarantee
Trustee at which the corporate trust business of the Guarantee Trustee shall, at
any particular time, be principally administered, which office at the date of
execution of this Guarantee is located at Rodney Square North, 1100 North Market
Street, Wilmington, DE 19890-0001.

                  "Covered Person" means any Holder of Capital Securities.

                  "Debentures" means the junior subordinated debentures of Blue
Valley Ban Corp, designated the Floating Rate Junior Subordinated Debt
Securities due 2033, held by the Institutional Trustee (as defined in the
Declaration) of the Issuer.

                  "Event of Default" has the meaning set forth in Section 2.4.

                  "Guarantee Payments" means the following payments or
distributions, without duplication, with respect to the Capital Securities, to
the extent not paid or made by the Issuer: (i) any accrued and unpaid
Distributions (as defined in the Declaration) which are required to be paid on
such Capital Securities to the extent the Issuer has funds available in the
Property Account (as defined in the Declaration) therefor at such time, (ii) the
Redemption Price (as defined in the Indenture) to the extent the Issuer has
funds available in the Property Account therefor at such time, with respect to
the Capital Securities at maturity on any Capital Securities called for
redemption by the Issuer, (iii) the Special Redemption Price (as defined in the
Indenture) to the extent the Issuer has funds available in the Property Account
therefor at such time, with respect to Capital Securities called for redemption
upon the occurrence of a Special Event (as defined in the Indenture), and (iv)
upon a voluntary or involuntary liquidation, dissolution, winding-up or
termination of the Issuer (other than in connection with the distribution of
Debentures to the Holders of the Capital Securities in exchange therefor as
provided in the Declaration), the lesser of (a) the aggregate of the liquidation
amount and all accrued and unpaid Distributions on the Capital Securities to the
date of payment, to the extent the Issuer has funds available in the Property
Account therefor at such time, and (b) the amount of assets of the Issuer
remaining available for distribution to Holders in liquidation of the Issuer
after satisfaction of liabilities to creditors of the Issuer as required by
applicable law (in either case, the "Liquidation Distribution").

                  "Guarantee Trustee" means Wilmington Trust Company, until a
Successor Guarantee Trustee has been appointed and has accepted such appointment
pursuant to the terms of this Guarantee and thereafter means each such Successor
Guarantee Trustee.

                  "Holder" means any holder, as registered on the books and
records of the Issuer, of any Capital Securities; provided, however, that, in
determining whether the holders of the requisite percentage of Capital
Securities have given any request, notice, consent or waiver hereunder, "Holder"
shall not include the Guarantor or any Affiliate of the Guarantor.

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                  "Indemnified Person" means the Guarantee Trustee (including in
its individual capacity), any Affiliate of the Guarantee Trustee, or any
officers, directors, shareholders, members, partners, employees,
representatives, nominees, custodians or agents of the Guarantee Trustee.

                  "Indenture" means the Indenture, dated as of April 10, 2003,
between the Guarantor and Wilmington Trust Company, not in its individual
capacity but solely as trustee, and any indenture supplemental thereto pursuant
to which the Debentures are to be issued to the Institutional Trustee of the
Issuer.

                  "Liquidation Distribution" has the meaning set forth in the
definition of "Guarantee Payments" herein.

                  "Majority in liquidation amount of the Capital Securities"
means Holder(s) of outstanding Capital Securities, voting together as a class,
but separately from the holders of Common Securities, of more than 50% of the
aggregate liquidation amount (including the stated amount that would be paid on
redemption, liquidation or otherwise, plus accrued and unpaid Distributions to,
but excluding, the date upon which the voting percentages are determined) of all
Capital Securities then outstanding.

                  "Obligations" means any costs, expenses or liabilities (but
not including liabilities related to taxes) of the Issuer, other than
obligations of the Issuer to pay to holders of any Trust Securities the amounts
due such holders pursuant to the terms of the Trust Securities.

                  "Officer's Certificate" means, with respect to any Person, a
certificate signed by one Authorized Officer of such Person. Any Officer's
Certificate delivered with respect to compliance with a condition or covenant
provided for in this Guarantee shall include:

                  (a)      a statement that each officer signing the Officer's
Certificate has read the covenant or condition and the definitions relating
thereto;

                  (b)      a brief statement of the nature and scope of the
examination or investigation undertaken by each officer in rendering the
Officer's Certificate;

                  (c)      a statement that each such officer has made such
examination or investigation as, in such officer's opinion, is necessary to
enable such officer to express an informed opinion as to whether or not such
covenant or condition has been complied with; and

                  (d)      a statement as to whether, in the opinion of each
such officer, such condition or covenant has been complied with.

                  "Person" means a legal person, including any individual,
corporation, estate, partnership, joint venture, association, joint stock
company, limited liability company, trust, unincorporated association, or
government or any agency or political subdivision thereof, or any other entity
of whatever nature.

                  "Responsible Officer" means, with respect to the Guarantee
Trustee, any officer within the Corporate Trust Office of the Guarantee Trustee
with direct responsibility for the

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administration of any matters relating to this Guarantee, including any vice
president, any assistant vice president, any secretary, any assistant
secretary, the treasurer, any assistant treasurer, any trust officer or other
officer of the Corporate Trust Office of the Guarantee Trustee customarily
performing functions similar to those performed by any of the above designated
officers and also means, with respect to a particular corporate trust matter,
any other officer to whom such matter is referred because of that officer's
knowledge of and familiarity with the particular subject.

             "Successor Guarantee Trustee" means a successor Guarantee Trustee
possessing the qualifications to act as Guarantee Trustee under Section 3.1.

             "Trust Securities" means the Common Securities and the Capital
Securities.

                                   ARTICLE II
               POWERS, DUTIES AND RIGHTS OF THE GUARANTEE TRUSTEE

SECTION 2.1. Powers and Duties of the Guarantee Trustee.

             (a)      This Guarantee shall be held by the Guarantee Trustee for
the benefit of the Holders of the Capital Securities, and the Guarantee Trustee
shall not transfer this Guarantee to any Person except a Holder of Capital
Securities exercising his or her rights pursuant to Section 4.4(b) or to a
Successor Guarantee Trustee on acceptance by such Successor Guarantee Trustee of
its appointment to act as Successor Guarantee Trustee. The right, title and
interest of the Guarantee Trustee shall automatically vest in any Successor
Guarantee Trustee, and such vesting and cessation of title shall be effective
whether or not conveyancing documents have been executed and delivered pursuant
to the appointment of such Successor Guarantee Trustee.

             (b)      If an Event of Default actually known to a Responsible
Officer of the Guarantee Trustee has occurred and is continuing, the Guarantee
Trustee shall enforce this Guarantee for the benefit of the Holders of the
Capital Securities.

             (c)      The Guarantee Trustee, before the occurrence of any Event
of Default and after the curing or waiving of all Events of Default that may
have occurred, shall undertake to perform only such duties as are specifically
set forth in this Guarantee, and no implied covenants shall be read into this
Guarantee against the Guarantee Trustee. In case an Event of Default has
occurred (that has not been cured or waived pursuant to Section 2.4(b)) and is
actually known to a Responsible Officer of the Guarantee Trustee, the Guarantee
Trustee shall exercise such of the rights and powers vested in it by this
Guarantee, and use the same degree of care and skill in its exercise thereof, as
a prudent person would exercise or use under the circumstances in the conduct of
his or her own affairs.

             (d)      No provision of this Guarantee shall be construed to
relieve the Guarantee Trustee from liability for its own negligent action, its
own negligent failure to act, or its own willful misconduct, except that:

                      (i)      prior to the occurrence of any Event of Default
             and after the curing or waiving of all Events of Default that may
             have occurred:

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                                    (A)      the duties and obligations of the
                           Guarantee Trustee shall be determined solely by the
                           express provisions of this Guarantee, and the
                           Guarantee Trustee shall not be liable except for the
                           performance of such duties and obligations as are
                           specifically set forth in this Guarantee, and no
                           implied covenants or obligations shall be read into
                           this Guarantee against the Guarantee Trustee; and

                                    (B)      in the absence of bad faith on the
                           part of the Guarantee Trustee, the Guarantee Trustee
                           may conclusively rely, as to the truth of the
                           statements and the correctness of the opinions
                           expressed therein, upon any certificates or opinions
                           furnished to the Guarantee Trustee and conforming to
                           the requirements of this Guarantee; but in the case
                           of any such certificates or opinions furnished to the
                           Guarantee Trustee, the Guarantee Trustee shall be
                           under a duty to examine the same to determine whether
                           or not on their face they conform to the requirements
                           of this Guarantee;

                           (ii)     the Guarantee Trustee shall not be liable
                  for any error of judgment made in good faith by a Responsible
                  Officer of the Guarantee Trustee, unless it shall be proved
                  that such Responsible Officer of the Guarantee Trustee or the
                  Guarantee Trustee was negligent in ascertaining the pertinent
                  facts upon which such judgment was made;

                           (iii)    the Guarantee Trustee shall not be liable
                  with respect to any action taken or omitted to be taken by it
                  in good faith in accordance with the written direction of the
                  Holders of not less than a Majority in liquidation amount of
                  the Capital Securities relating to the time, method and place
                  of conducting any proceeding for any remedy available to the
                  Guarantee Trustee, or exercising any trust or power conferred
                  upon the Guarantee Trustee under this Guarantee; and

                           (iv)     no provision of this Guarantee shall require
                  the Guarantee Trustee to expend or risk its own funds or
                  otherwise incur personal financial liability in the
                  performance of any of its duties or in the exercise of any of
                  its rights or powers, if the Guarantee Trustee shall have
                  reasonable grounds for believing that the repayment of such
                  funds is not reasonably assured to it under the terms of this
                  Guarantee, or security and indemnity, reasonably satisfactory
                  to the Guarantee Trustee, against such risk or liability is
                  not reasonably assured to it.

SECTION 2.2.      Certain Rights of the Guarantee Trustee.

                  (a)      Subject to the provisions of Section 2.1:

                           (i)      The Guarantee Trustee may conclusively rely,
                  and shall be fully protected in acting or refraining from
                  acting upon, any resolution, certificate, statement,
                  instrument, opinion, report, notice, request, direction,
                  consent, order, bond, debenture, note, other evidence of
                  indebtedness or other paper or document believed by it to be
                  genuine and to have been signed, sent or presented by the
                  proper party or parties.

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<PAGE>

                           (ii)     Any direction or act of the Guarantor
                  contemplated by this Guarantee shall be sufficiently evidenced
                  by an Officer's Certificate.

                           (iii)    Whenever, in the administration of this
                  Guarantee, the Guarantee Trustee shall deem it desirable that
                  a matter be proved or established before taking, suffering or
                  omitting any action hereunder, the Guarantee Trustee (unless
                  other evidence is herein specifically prescribed) may, in the
                  absence of bad faith on its part, request and conclusively
                  rely upon an Officer's Certificate of the Guarantor which,
                  upon receipt of such request, shall be promptly delivered by
                  the Guarantor.

                           (iv)     The Guarantee Trustee shall have no duty to
                  see to any recording, filing or registration of any instrument
                  or other writing (or any rerecording, refiling or registration
                  thereof).

                           (v)      The Guarantee Trustee may consult with
                  counsel of its selection, and the advice or opinion of such
                  counsel with respect to legal matters shall be full and
                  complete authorization and protection in respect of any action
                  taken, suffered or omitted by it hereunder in good faith and
                  in accordance with such advice or opinion. Such counsel may be
                  counsel to the Guarantor or any of its Affiliates and may
                  include any of its employees. The Guarantee Trustee shall have
                  the right at any time to seek instructions concerning the
                  administration of this Guarantee from any court of competent
                  jurisdiction.

                           (vi)     The Guarantee Trustee shall be under no
                  obligation to exercise any of the rights or powers vested in
                  it by this Guarantee at the request or direction of any
                  Holder, unless such Holder shall have provided to the
                  Guarantee Trustee such security and indemnity, reasonably
                  satisfactory to the Guarantee Trustee, against the costs,
                  expenses (including attorneys' fees and expenses and the
                  expenses of the Guarantee Trustee's agents, nominees or
                  custodians) and liabilities that might be incurred by it in
                  complying with such request or direction, including such
                  reasonable advances as may be requested by the Guarantee
                  Trustee; provided, however, that nothing contained in this
                  Section 2.2(a)(vi) shall be taken to relieve the Guarantee
                  Trustee, upon the occurrence of an Event of Default, of its
                  obligation to exercise the rights and powers vested in it by
                  this Guarantee.

                           (vii)    The Guarantee Trustee shall not be bound to
                  make any investigation into the facts or matters stated in any
                  resolution, certificate, statement, instrument, opinion,
                  report, notice, request, direction, consent, order, bond,
                  debenture note, other evidence of indebtedness or other paper
                  or document, but the Guarantee Trustee, in its discretion, may
                  make such further inquiry or investigation into such facts or
                  matters as it may see fit.

                           (viii)   The Guarantee Trustee may execute any of the
                  trusts of powers hereunder or perform any duties hereunder
                  either directly or by or through agents, nominees, custodians
                  or attorneys, and the Guarantee Trustee shall not be

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                  responsible for any misconduct or negligence on the part of
                  any agent or attorney appointed with due care by it hereunder.

                           (ix)     Any action taken by the Guarantee Trustee or
                  its agents hereunder shall bind the Holders of the Capital
                  Securities, and the signature of the Guarantee Trustee or its
                  agents alone shall be sufficient and effective to perform any
                  such action. No third party shall be required to inquire as to
                  the authority of the Guarantee Trustee to so act or as to its
                  compliance with any of the terms and provisions of this
                  Guarantee, both of which shall be conclusively evidenced by
                  the Guarantee Trustee's or its agent's taking such action.

                           (x)      Whenever in the administration of this
                  Guarantee the Guarantee Trustee shall deem it desirable to
                  receive instructions with respect to enforcing any remedy or
                  right or taking any other action hereunder, the Guarantee
                  Trustee (A) may request instructions from the Holders of a
                  Majority in liquidation amount of the Capital Securities, (B)
                  may refrain from enforcing such remedy or right or taking such
                  other action until such instructions are received and (C)
                  shall be protected in conclusively relying on or acting in
                  accordance with such instructions.

                          (xi)      The Guarantee Trustee shall not be liable
                  for any action taken, suffered, or omitted to be taken by it
                  in good faith and reasonably believed by it to be authorized
                  or within the discretion or rights or powers conferred upon it
                  by this Guarantee.

                  (b)      No provision of this Guarantee shall be deemed to
impose any duty or obligation on the Guarantee Trustee to perform any act or
acts or exercise any right, power, duty or obligation conferred or imposed on
it, in any jurisdiction in which it shall be illegal or in which the Guarantee
Trustee shall be unqualified or incompetent in accordance with applicable law to
perform any such act or acts or to exercise any such right, power, duty or
obligation. No permissive power or authority available to the Guarantee Trustee
shall be construed to be a duty.

SECTION 2.3.      Not Responsible for Recitals or Issuance of Guarantee.

                  The recitals contained in this Guarantee shall be taken as the
statements of the Guarantor, and the Guarantee Trustee does not assume any
responsibility for their correctness. The Guarantee Trustee makes no
representation as to the validity or sufficiency of this Guarantee.

SECTION 2.4.      Events of Default: Waiver.

                  (a)      An Event of Default under this Guarantee will occur
upon the failure of the Guarantor to perform any of its payment or other
obligations hereunder.

                  (b)      The Holders of a Majority in liquidation amount of
the Capital Securities may, voting or consenting as a class, on behalf of the
Holders of all of the Capital Securities, waive any past Event of Default and
its consequences. Upon such waiver, any such Event of Default shall cease to
exist, and shall be deemed to have been cured, for every purpose of this

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<PAGE>

Guarantee, but no such waiver shall extend to any subsequent or other default or
Event of Default or impair any right consequent thereon.

SECTION 2.5.      Events of Default: Notice.

                  (a)      The Guarantee Trustee shall, within 90 days after the
occurrence of an Event of Default, transmit by mail, first class postage
prepaid, to the Holders of the Capital Securities, notices of all Events of
Default actually known to a Responsible Officer of the Guarantee Trustee, unless
such defaults have been cured before the giving of such notice, provided,
however, that the Guarantee Trustee shall be protected in withholding such
notice if and so long as a Responsible Officer of the Guarantee Trustee in good
faith determines that the withholding of such notice is in the interests of the
Holders of the Capital Securities.

                  (b)      The Guarantee Trustee shall not be charged with
knowledge of any Event of Default unless the Guarantee Trustee shall have
received written notice thereof from the Guarantor or a Holder of the Capital
Securities, or a Responsible Officer of the Guarantee Trustee charged with the
administration of this Guarantee shall have actual knowledge thereof.

                                   ARTICLE III
                              THE GUARANTEE TRUSTEE

SECTION 3.1.      The Guarantee Trustee: Eligibility.

                  (a) There shall at all times be a Guarantee Trustee which
shall:

                           (i)      not be an Affiliate of the Guarantor; and

                           (ii)     be a corporation or national association
                  organized and doing business under the laws of the United
                  States of America or any state of territory thereof or of the
                  District of Columbia, or Person authorized under such laws to
                  exercise corporate trust powers, having a combined capital and
                  surplus of at least 50 million U.S. dollars ($50,000,000), and
                  subject to supervision or examination by federal, state,
                  territorial or District of Columbia authority. If such
                  corporation or national association publishes reports of
                  condition at least annually, pursuant to law or to the
                  requirements of the supervising or examining authority
                  referred to above, then, for the purposes of this Section
                  3.1(a)(ii), the combined capital and surplus of such
                  corporation or national association shall be deemed to be its
                  combined capital and surplus as set forth in its most recent
                  report of condition so published.

                  (b)      If at any time the Guarantee Trustee shall cease to
be eligible to so act under Section 3.1(a), the Guarantee Trustee shall
immediately resign in the manner and with the effect set forth in Section
3.2(c).

                  (c)      If the Guarantee Trustee has or shall acquire any
"conflicting interest" within the meaning of Section 310(b) of the Trust
Indenture Act, the Guarantee Trustee shall either eliminate such interest or
resign to the extent and in the manner provided by, and subject to, this
Guarantee.

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<PAGE>

SECTION 3.2.      Appointment, Removal and Resignation of the Guarantee Trustee.

                  (a)      Subject to Section 3.2(b), the Guarantee Trustee may
be appointed or removed without cause at any time by the Guarantor except during
an Event of Default.

                  (b)      The Guarantee Trustee shall not be removed in
accordance with Section 3.2(a) until a Successor Guarantee Trustee has been
appointed and has accepted such appointment by written instrument executed by
such Successor Guarantee Trustee and delivered to the Guarantor.

                  (c)      The Guarantee Trustee appointed to office shall hold
office until a Successor Guarantee Trustee shall have been appointed or until
its removal or resignation. The Guarantee Trustee may resign from office
(without need for prior or subsequent accounting) by an instrument in writing
executed by the Guarantee Trustee and delivered to the Guarantor, which
resignation shall not take effect until a Successor Guarantee Trustee has been
appointed and has accepted such appointment by an instrument in writing executed
by such Successor Guarantee Trustee and delivered to the Guarantor and the
resigning Guarantee Trustee.

                  (d)      If no Successor Guarantee Trustee shall have been
appointed and accepted appointment as provided in this Section 3.2 within 60
days after delivery of an instrument of removal or resignation, the Guarantee
Trustee resigning or being removed may petition any court of competent
jurisdiction for appointment of a Successor Guarantee Trustee. Such court may
thereupon, after prescribing such notice, if any, as it may deem proper, appoint
a Successor Guarantee Trustee.

                  (e)      No Guarantee Trustee shall be liable for the acts or
omissions to act of any Successor Guarantee Trustee.

                  (f)      Upon termination of this Guarantee or removal or
resignation of the Guarantee Trustee pursuant to this Section 3.2, the Guarantor
shall pay to the Guarantee Trustee all amounts owing to the Guarantee Trustee
under Sections 7.2 and 7.3 accrued to the date of such termination, removal or
resignation.

                                   ARTICLE IV
                                   GUARANTEE

SECTION 4.1.      Guarantee.

                  (a)      The Guarantor irrevocably and unconditionally agrees
to pay in full to the Holders the Guarantee Payments (without duplication of
amounts theretofore paid by the Issuer), as and when due, regardless of any
defense (except as defense of payment by the Issuer), right of set-off or
counterclaim that the Issuer may have or assert. The Guarantor's obligation to
make a Guarantee Payment may be satisfied by direct payment of the required
amounts by the Guarantor to the Holders or by causing the Issuer to pay such
amounts to the Holders.

                  (b)      The Guarantor hereby also agrees to assume any and
all Obligations of the Issuer and in the event any such Obligation is not so
assumed, subject to the terms and conditions hereof, the Guarantor hereby
irrevocably and unconditionally guarantees to each Beneficiary the

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<PAGE>

full payment, when and as due, of any and all Obligations to such Beneficiaries.
This Guarantee is intended to be for the Beneficiaries who have received notice
hereof.

SECTION 4.2.      Waiver of Notice and Demand.

                  The Guarantor hereby waives notice of acceptance of this
Guarantee and of any liability to which it applies or may apply, presentment,
demand for payment, any right to require a proceeding first against the Issuer
or any other Person before proceeding against the Guarantor, protest, notice of
nonpayment, notice of dishonor, notice of redemption and all other notices and
demands.

SECTION 4.3.      Obligations Not Affected.

                  The obligations, covenants, agreements and duties of the
Guarantor under this Guarantee shall in no way be affected or impaired by reason
of the happening from time to time of any of the following:

                  (a)      the release or waiver, by operation of law or
otherwise, of the performance or observance by the Issuer of any express or
implied agreement, covenant, term or condition relating to the Capital
Securities to be performed or observed by the Issuer;

                  (b)      the extension of time for the payment by the Issuer
of all or any portion of the Distributions, Redemption Price, Special Redemption
Price, Liquidation Distribution or any other sums payable under the terms of the
Capital Securities or the extension of time for the performance of any other
obligation under, arising out of, or in connection with, the Capital Securities
(other than an extension of time for the payment of the Distributions,
Redemption Price, Special Redemption Price, Liquidation Distribution or other
sums payable that results from the extension of any interest payment period on
the Debentures or any extension of the maturity date of the Debentures permitted
by the Indenture);

                  (c)      any failure, omission, delay or lack of diligence on
the part of the Holders to enforce, assert or exercise any right, privilege,
power or remedy conferred on the Holders pursuant to the terms of the Capital
Securities, or any action on the part of the Issuer granting indulgence or
extension of any kind;

                  (d)      the voluntary or involuntary liquidation,
dissolution, sale of any collateral, receivership, insolvency, bankruptcy,
assignment for the benefit of creditors, reorganization, arrangement,
composition or readjustment of debt of, or other similar proceedings affecting,
the Issuer or any of the assets of the Issuer;

                  (e)      any invalidity of, or defect or deficiency in, the
Capital Securities;

                  (f)      the settlement or compromise of any obligation
guaranteed hereby or hereby incurred; or

                  (g)      any other circumstance whatsoever that might
otherwise constitute a legal or equitable discharge or defense of a guarantor,
it being the intent of this Section 4.3 that the

                                       10
<PAGE>

obligations of the Guarantor hereunder shall be absolute and unconditional under
any and all circumstances.

                  There shall be no obligation of the Holders to give notice to,
or obtain consent of, the Guarantor with respect to the happening of any of the
foregoing.

SECTION 4.4.      Rights of Holders.

                  (a)      The Holders of a Majority in liquidation amount of
the Capital Securities have the right to direct the time, method and place of
conducting any proceeding for any remedy available to the Guarantee Trustee in
respect of this Guarantee or to direct the exercise of any trust or power
conferred upon the Guarantee Trustee under this Guarantee; provided, however,
that (subject to Sections 2.1 and 2.2) the Guarantee Trustee shall Have the
right to decline to follow any such direction if the Guarantee Trustee shall
determine that the actions so directed would be unjustly prejudicial to the
Holders not taking part in such direction or if the Guarantee Trustee being
advised by legal counsel determines that the action or proceeding so directed
may not lawfully be taken or if the Guarantee Trustee in good faith by its board
of directors or trustees, executive committee or a trust committee of directors
or trustees and/or Responsible Officers shall determine that the action or
proceeding so directed would involve the Guarantee Trustee in personal
liability.

                  (b)      Any Holder of Capital Securities may institute a
legal proceeding directly against the Guarantor to enforce the Guarantee
Trustee's rights under this Guarantee, without first instituting a legal
proceeding against the Issuer, the Guarantee Trustee or any other Person. The
Guarantor waives any right or remedy to require that any such action be brought
first against the Issuer, the Guarantee Trustee or any other Person before so
proceeding directly against the Guarantor.

SECTION 4.5.      Guarantee of Payment.

                  This Guarantee creates a guarantee of payment and not of
collection.

SECTION 4.6.      Subrogation.

                  The Guarantor shall be subrogated to all (if any) rights of
the Holders of Capital Securities against the Issuer in respect of any amounts
paid to such Holders by the Guarantor under this Guarantee; provided, however,
that the Guarantor shall not (except to the extent required by applicable
provisions of law) be entitled to enforce or exercise any right that it may
acquire by way of subrogation or any indemnity, reimbursement or other
agreement, in all cases as a result of payment under this Guarantee, if, after
giving effect to any such payment, any amounts are due and unpaid under this
Guarantee. If any amount shall be paid to the Guarantor in violation of the
preceding sentence, the Guarantor agrees to hold such amount in trust for the
Holders and to pay over such amount to the Holders.

SECTION 4.7.      Independent Obligations.

The Guarantor acknowledges that its obligations hereunder are independent of the
obligations of the Issuer with respect to the Capital Securities and that the
Guarantor shall be liable as principal

                                       11
<PAGE>

and as debtor hereunder to make Guarantee Payments pursuant to the terms of this
Guarantee notwithstanding the occurrence of any event referred to in subsections
(a) through (g), inclusive, of Section 4.3 hereof.

SECTION 4.8.      Enforcement.

                  A Beneficiary may enforce the Obligations of the Guarantor
contained in Section 4.1(b) directly against the Guarantor, and the Guarantor
waives any right or remedy to require that any action be brought against the
Issuer or any other person or entity before proceeding against the Guarantor.

                  The Guarantor shall be subrogated to all rights (if any) of
any Beneficiary against the Issuer in respect of any amounts paid to the
Beneficiaries by the Guarantor under this Guarantee; provided, however, that the
Guarantor shall not (except to the extent required by applicable provisions of
law) be entitled to enforce or exercise any rights that it may acquire by way of
subrogation or any indemnity, reimbursement or other agreement, in all cases as
a result of payment under this Guarantee, if, after giving effect to such
payment, any amounts are due and unpaid under this Guarantee.

                                    ARTICLE V
                    LIMITATION OF TRANSACTIONS; SUBORDINATION

SECTION 5.1.      Limitation of Transactions.

                  So long as any Capital Securities remain outstanding, if (a)
there shall have occurred and be continuing an Event of Default or (b) the
Guarantor shall have selected an Extension Period as provided in the Declaration
and such period, or any extension thereof, shall have commenced and be
continuing, then the Guarantor may not (x) declare or pay any dividends or
distributions on, or redeem, purchase, acquire, or make a liquidation payment
with respect to, any of the Guarantor's capital stock or (y) make any payment of
principal of or interest or premium, if any, on or repay, repurchase or redeem
any debt securities of the Guarantor that rank pari passu in all respects with
or junior in interest to the Debentures (other than (i) payments under this
Guarantee, (ii) repurchases, redemptions or other acquisitions of shares of
capital stock of the Guarantor (A) in connection with any employment contract,
benefit plan or other similar arrangement with or for the benefit of one or more
employees, officers, directors, or consultants, (B) in connection with a
dividend reinvestment or stockholder stock purchase plan or (C) in connection
with the issuance of capital stock of the Guarantor (or securities convertible
into or exercisable for such capital stock), as consideration in an acquisition
transaction entered into prior to the occurrence of the Event of Default or the
applicable Extension Period, (iii) as a result of any exchange or conversion of
any class or series of the Guarantor's capital stock (or any capital stock of a
subsidiary of the Guarantor) for any class or series of the Guarantor's capital
stock or of any class or series of the Guarantor's indebtedness for any class or
series of the Guarantor's capital stock, (iv) the purchase of fractional
interests in shares of the Guarantor's capital stock pursuant to the conversion
or exchange provisions of such capital stock or the security being converted or
exchanged, (v) any declaration of a dividend in connection with any
stockholder's rights plan, or the issuance of rights, stock or other property
under any stockholder's rights plan, or the redemption or

                                       12
<PAGE>

repurchase of rights pursuant thereto, or (vi) any dividend in the form of
stock, warrants, options or other rights where the dividend stock or the stock
issuable upon exercise of such warrants, options or other rights is the same
stock 3$ that on which the dividend is being paid or ranks pari passu with or
junior to such stock).

SECTION 5.2.      Ranking.

                  This Guarantee will constitute an unsecured obligation of the
Guarantor and will rank subordinate and junior in right of payment to all
present and future Senior Indebtedness (as defined in the Indenture) of the
Guarantor. By their acceptance thereof, each Holder of Capital Securities agrees
to the foregoing provisions of this Guarantee and the other terms set forth
herein.

                                   ARTICLE VI
                                  TERMINATION

SECTIONS 6.1.     Termination.

                  This Guarantee shall terminate as to the Capital Securities
(i) upon full payment of the Redemption Price or the Special Redemption Price,
as the case may be, of all Capital Securities then outstanding, (ii) upon the
distribution of all of the Debentures to the Holders of all of the Capital
Securities or (iii) upon full payment of the amounts payable in accordance with
the Declaration upon dissolution of the Issuer. This Guarantee will continue to
be effective or will be reinstated, as the case may be, if at any time any
Holder of Capital Securities must restore payment of any sums paid under the
Capital Securities or under this Guarantee.

                                   ARTICLE VII
                                 INDEMNIFICATION

SECTION 7.1.      Exculpation.

                  (a)      No Indemnified Person shall be liable, responsible or
accountable in damages or otherwise to the Guarantor or any Covered Person for
any loss, damage or claim incurred by reason of any act or omission of such
Indemnified Person in good faith in accordance with this Guarantee and in a
manner that such Indemnified Person reasonably believed to be within the scope
of the authority conferred on such Indemnified Person by this Guarantee or by
law, except that an Indemnified Person shall be liable for any such loss, damage
or claim incurred by reason of such Indemnified Person's negligence or willful
misconduct with respect to such acts or omissions.

                  (b)      An Indemnified Person shall be fully protected in
relying in good faith upon the records of the Issuer or the Guarantor and upon
such information, opinions, reports or statements presented to the Issuer or the
Guarantor by any Person as to matters the Indemnified Person reasonably believes
are within such other Person's professional or expert competence and who, if
selected by such Indemnified Person, has been selected with reasonable care by
such Indemnified Person, including information, opinions, reports or statements
as to the value and amount of the assets, liabilities, profits, losses, or any
other facts pertinent to the existence and

                                       13
<PAGE>

amount of assets from which Distributions to Holders of Capital Securities might
properly be paid.

SECTION 7.2.      Indemnification.

                  (a)      The Guarantor agrees to indemnify each Indemnified
Person for, and to hold each Indemnified Person harmless against, any and all
loss, liability, damage, claim or expense incurred without negligence or willful
misconduct on the part of the Indemnified Person, arising out of or in
connection with the acceptance or administration of the trust or trusts
hereunder, including but not limited to the costs and expenses (including
reasonable legal fees and expenses) of the Indemnified Person defending itself
against, or investigating, any claim or liability in connection with the
exercise or performance of any of the Indemnified Person's powers or duties
hereunder. The obligation to indemnify as set forth in this Section 7.2 shall
survive the resignation or removal of the Guarantee Trustee and the termination
of this Guarantee.

                  (b)      Promptly after receipt by an Indemnified Person under
this Section 7.2 of notice of the commencement of any action, such Indemnified
Person will, if a claim in respect thereof is to be made against the Guarantor
under this Section 7.2, notify the Guarantor in writing of the commencement
thereof; but the failure so to notify the Guarantor (i) will not relieve the
Guarantor from liability under paragraph (a) above unless and to the extent that
the Guarantor did not otherwise learn of such action and such failure results in
the forfeiture by the Guarantor of substantial rights and defenses and (ii) will
not, in any event, relieve the Guarantor from any obligations to any Indemnified
Person other than the indemnification obligation provided in paragraph (a)
above. The Guarantor shall be entitled to appoint counsel of the Guarantor's
choice at the Guarantor's expense to represent the Indemnified Person in any
action for which indemnification is sought (in which case the Guarantor shall
not thereafter be responsible for the fees and expenses of any separate counsel
retained by the Indemnified Person or Persons except as set forth below);
provided, however, that such counsel shall be satisfactory to the Indemnified
Person. Notwithstanding the Guarantor's election to appoint counsel to represent
the Indemnified Person in any action, the Indemnified Person shall have the
right to employ separate counsel (including local counsel), and the Guarantor
shall bear the reasonable fees, costs and expenses of such separate counsel, if
(i) the use of counsel chosen by the Guarantor to represent the Indemnified
Person would present such counsel with a conflict of interest, (ii) the actual
or potential defendants in, or targets of, any such action include both the
Indemnified Person and the Guarantor and the Indemnified Person shall have
reasonably concluded that there may be legal defenses available to it and/or
other Indemnified Persons which are different from or additional to those
available to the Guarantor, (iii) the Guarantor shall not have employed counsel
satisfactory to the Indemnified Person to represent the Indemnified Person
within a reasonable time after notice of the institution of such action or(iv)
the Guarantor shall authorize the Indemnified Person to employ separate counsel
at the expense of the Guarantor. The Guarantor will not, without the prior
written consent of the Indemnified Persons, settle or compromise or consent to
the entry of any judgment with respect to any pending or threatened claim,
action, suit or proceeding in respect of which indemnification or contribution
may be sought hereunder (whether or not the Indemnified Persons are actual or
potential parties to such claim or action) unless such settlement,

                                       14
<PAGE>

compromise or consent includes an unconditional release of each Indemnified
Person from all liability arising out of such claim, action, suit or proceeding.

SECTION 7.3.      Compensation: Reimbursement of Expenses.

                  The Guarantor agrees:

                  (a)      to pay to the Guarantee Trustee from time to time
such compensation for all services rendered by it hereunder as the parties shall
agree to from time to time (which compensation shall not be limited by any
provision of law in regard to the compensation of a trustee of an express
trust); and

                  (b)      except as otherwise expressly provided herein, to
reimburse the Guarantee Trustee upon request for all reasonable expenses,
disbursements and advances incurred or made by it in accordance with any
provision of this Guarantee (including the reasonable compensation and the
expenses and disbursements of its agents and counsel), except any such expense,
disbursement or advance as may be attributable to its negligence or willful
misconduct.

                  The provisions of this Section 7.3 shall survive the
resignation or removal of the Guarantee Trustee and the termination of this
Guarantee.

                                  ARTICLE VIII
                                  MISCELLANEOUS

SECTION 8.1.      Successors and Assigns.

                  All guarantees and agreements contained in this Guarantee
shall bind the successors, assigns, receivers, trustees and representatives of
the Guarantor and shall inure to the benefit of the Holders of the Capital
Securities then outstanding. Except in connection with any merger or
consolidation of the Guarantor with or into another entity or any sale, transfer
or lease of the Guarantor's assets to another entity, in each case to the extent
permitted under the Indenture, the Guarantor may not assign its rights or
delegate its obligations under this Guarantee without the prior approval of the
Holders of not less than a Majority in liquidation amount of the Capital
Securities.

SECTION 8.2.      Amendments.

                  Except with respect to any changes that do not adversely
affect the rights of Holders of the Capital Securities in any material respect
(in which case no consent of Holders will be required), this Guarantee may be
amended only with the prior approval of the Holders of not less than a Majority
in liquidation amount of the Capital Securities. The provisions of the
Declaration with respect to amendments thereof shall apply equally with respect
to amendments of the Guarantee.

                                       15
<PAGE>

SECTION 8.3.      Notices.

                  All notices provided for in this Guarantee shall be in
writing, duly signed by the party giving such notice, and shall be delivered,
telecopied or mailed by first class mail, as follows:

                  (a)      If given to the Guarantee Trustee, at the Guarantee
Trustee's mailing address set forth below (or such other address as the
Guarantee Trustee may give notice of to the Holders of the Capital Securities):

                           Wilmington Trust Company
                           Rodney Square North
                           1100 North Market Street
                           Wilmington, DE 19890-0001
                           Attention: Corporate Trust Administrator
                           Telecopy: 302-651-8882
                           Telephone: 302-651-1000

                  (b)      If given to the Guarantor, at the Guarantor's mailing
address set forth below (or such other address as the Guarantor may give notice
of to the Holders of the Capital Securities and to the Guarantee Trustee):

                           Blue Valley Ban Corp
                           11935 Riley
                           Overland Park, KS 66213
                           Attention: Mark A. Fortino
                           Telecopy; 913-234-7145
                           Telephone: 913-234-2345

                  (c)      If given to any Holder of the Capital Securities, at
the address set forth on the books and records of the Issuer.

                  All such notices shall be deemed to have been given when
received in person, telecopied with receipt confirmed, or mailed by first class
mail, postage prepaid, except that if a notice or other document is refused
delivery or cannot be delivered because of a changed address of which no notice
was given, such notice or other document shall be deemed to have been delivered
on the date of such refusal or inability to deliver.

SECTION 8.4.      Benefit.

                  This Guarantee is solely for the benefit of the Holders of the
Capital Securities and, subject to Section 2.1 (a), is not separately
transferable from the Capital Securities.

 SECTION 8.5.     Governing Law.

                  THIS GUARANTEE SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK, WITHOUT REGARD TO CONFLICT OF
LAWS PRINCIPLES THEREOF.

                                       16

<PAGE>

SECTION 8.6. Counterparts.

         This Guarantee may contain more than one counterpart of the signature
page and this Guarantee may be executed by the affixing of the signature of the
Guarantor and the Guarantee Trustee to any of such counterpart signature pages.
All of such counterpart signature pages shall be read as though one, and they
shall have the same force and effect as though all of the signers had signed a
single signature page.

                                       17
<PAGE>

         THIS GUARANTEE is executed as of the day and year first above written.

                                     BLUEVALLEY BANCORP,
                                     as Guarantor

                                     By: /s/ Robert D. Regnier
                                         ------------------------------
                                         Name: Robert D. Regnier
                                         Title: President Chief Executive
                                                Officer and Director

                                     WILMINGTON TRUST COMPANY, as
                                     Guarantee Trustee

                                     By: /s/ Donald G. MaCkelcan
                                         ------------------------------
                                         Name: Donald G. MacKelcan
                                         Title: Vice President

Guarantee Agreement