<PAGE>

                                                                     EXHIBIT 4.3

                     BERKSHIRE HATHAWAY FINANCE CORPORATION

                             .......................

                           4.20% SENIOR NOTES DUE 2010

                                                                    CUSIP: _____
                                                                    ISIN: ______

NO. 1                                                                 $_________
                                    (as revised by the Schedule of Increases and
                                   Decreases in Global Security attached hereto)

              BERKSHIRE HATHAWAY FINANCE CORPORATION, a corporation duly
     organized and existing under the laws of the State of Delaware (herein
     called the "Company", which term includes any successor Person under the
     Indenture hereinafter referred to), for value received, hereby promises to
     pay to CEDE & CO., the registered Holder hereof, the principal sum of
     _____________ ($____) (as revised by the Schedule of Increases and
     Decreases in Global Security attached hereto) on December 15, 2010, and to
     pay interest thereon from and including December 15, 2003 or from and
     including the most recent Interest Payment Date (as defined below) to which
     interest has been paid or duly provided for, semi-annually on June 15 and
     December 15 in each year, commencing June 15, 2004 (each an "Interest
     Payment Date"), at the rate of 4.20% per annum (as adjusted, if at all,
     pursuant to such Indenture, the "Interest Rate"), until the principal
     hereof is paid or made available for payment; provided that any principal,
     and any such installment of interest, which is overdue shall bear interest
     at the Interest Rate (to the extent that the payment of such interest shall
     be legally enforceable), from the dates such amounts are due until they are
     paid or made available for payment, and such interest shall be payable on
     demand. The interest so payable, and punctually paid or duly provided for,
     on any Interest Payment Date will, as provided in such Indenture, be paid
     to the Person in whose name this Debt Security (or one or more Predecessor
     Securities) is registered at the close of business on the Regular Record
     Date for such interest. Any such interest not so punctually paid or duly
     provided for will forthwith cease to be payable to the Holder on such
     Regular Record Date and may either be paid to the Person in whose name this
     Debt Security (or one or more Predecessor Securities) is registered at the
     close of business on a Special Record Date for the payment of such
     Defaulted Interest to be fixed by the Trustee, notice whereof shall be
     given to Holders of Debt Securities of this series not less than 10 days
     prior to such Special Record Date, or be paid at any time in any other
     lawful manner not inconsistent with the requirements of any securities
     exchange on which the Debt Securities of this series may be listed, and
     upon such notice as may be required by such exchange, all as more fully
     provided in such Indenture.

              Payment of the principal of and interest on this Debt Security
     will be made at the office or agency of the Company maintained for that
     purpose in the City of New York, New York (or, if the Company does not
     maintain such office or agency, at the corporate trust office of the
     Trustee in the City of New York or if the Trustee does not maintain an
     office in the City of New York, at the office of a Paying Agent in the City
     of New York), in such coin or currency of the United States of America as
     at the time of payment is legal tender for payment of public and private
     debt; provided, however, that at the option of the Company payments of
     principal or interest may be made by check mailed to the address of the
     Person entitled thereto as such address shall appear in the Security
     Register.

              This Debt Security may be redeemed, in whole or in part, at the
     option of the Company, at any time prior to its maturity at a redemption
     price equal to the greater of (A) 100% of the principal amount to be
     redeemed or (B) as determined by the Quotation Agent, the sum of the

<PAGE>

     present values of the remaining scheduled payments of principal and
     interest on the portion of this Debt Security being redeemed, not including
     any portion of such payments of interest accrued as of the date fixed for
     redemption, discounted to the date fixed for redemption on a semi-annual
     basis assuming a 360-day year consisting of twelve 30-day months, at the
     Adjusted Treasury Rate plus ten basis points, plus, in each case, accrued
     interest on the portion of this Debt Security being redeemed to the date
     fixed for redemption.

              The Quotation Agent will select a Comparable Treasury Issue, and
     the Reference Dealers will provide the Company and the Trustee with the
     Reference Dealer Quotations. The Company will calculate the Comparable
     Treasury Price.

              "Adjusted Treasury Rate" means, for any date fixed for redemption,
     the rate per year equal to the semi-annual equivalent yield to maturity of
     the Comparable Treasury Issue assuming a price for the Comparable Treasury
     Issue equal to the Comparable Treasury Price for the date fixed for
     redemption, in each case expressed as a percentage of its principal amount.

              "Comparable Treasury Issue" means, for any date fixed for
     redemption, the U.S. Treasury security selected by the Quotation Agent
     which has a maturity comparable to the remaining maturity of this Debt
     Security as of the date fixed for redemption, which would be used in
     accordance with customary financial practice to price new issues of
     corporate debt securities with a maturity comparable to the remaining
     maturity of this Debt Security as of the date fixed for redemption.

              "Comparable Treasury Price" means, for any Comparable Treasury
     Issue, the price after eliminating the highest and the lowest Reference
     Dealer Quotations and then calculating the average of the remaining
     Reference Dealer Quotations; provided, however, if the Company obtains
     fewer than three Reference Dealer Quotations, the Company will, when
     calculating the Comparable Treasury Price, calculate the average of all the
     Reference Dealer Quotations and not eliminate any such quotations.

              "Quotation Agent" means Goldman, Sachs & Co. or its successor.

              "Reference Dealers" means Goldman, Sachs & Co. or its successor
     and two or more other primary U.S. Government securities dealers in the
     City of New York appointed by the Company, provided, however, that if
     Goldman, Sachs & Co. or its successor ceases to be a primary U.S.
     Government securities dealer, the Company will appoint another primary U.S.
     Government securities dealer as a substitute.

              "Reference Dealer Quotations" means, for any Comparable Treasury
     Issue, the average of the bid and asked prices for such Comparable Treasury
     Issue (expressed in each case as a percentage of its principal amount)
     quoted in writing by the Reference Dealers to the Company and the Trustee
     as of 5:00 p.m. (EST) on the third business day before the relevant date
     fixed for redemption.

              "Regular Record Date" means, with respect to any Interest Payment
     Date, June 1 or April 1, as the case may be, immediately preceding such
     Interest Payment Date.

              The Company may elect to effect a redemption in accordance with
     these provisions at any time and on any date. However, the Company must
     give the Holders of this Debt Security notice, as provided in the
     Indenture, of the redemption not less than 30 days or more than 60 days
     before the date fixed for redemption. If the Company elects to redeem fewer
     than the full principal amount of this Debt Security, the Trustee will
     select the amount to be redeemed on a pro rata basis, by lot or by such
     other method of random selection, if any, that the Trustee deems fair and
     appropriate.

<PAGE>

              Reference is hereby made to the further provisions of this Debt
     Security set forth on the reverse hereof, which further provisions shall
     for all purposes have the same effect as if set forth at this place.

              Unless the certificate of authentication hereon has been executed
     by the Trustee referred to on the reverse hereof by manual signature, this
     Debt Security shall not be entitled to any benefit under the Indenture or
     be valid or obligatory for any purpose.

<PAGE>

              IN WITNESS WHEREOF, the Company has caused this instrument to be
     duly executed.

              Dated: _______, 2004                BERKSHIRE HATHAWAY FINANCE
                                                  CORPORATION

                                                  By: _________________________
                                                  Name: Marc D. Hamburg
                                                  Title: President

              Attest:

              ______________________
              Name: Jerry W. Hufton
              Title: Secretary

<PAGE>

                           [REVERSE OF DEBT SECURITY]

              This Debt Security is one of a duly authorized series of notes of
     the Company (herein called the "Debt Securities"), issued and to be issued
     in one or more series under an Indenture, dated as of December 22, 2003
     (herein called the "Base Indenture", and as supplemented by the Officers'
     Certificate, dated as of ______, herein, together with the Base Indenture,
     called the "Indenture"), among the Company, as issuer, Berkshire Hathaway
     Inc., as guarantor (herein the "Guarantor" which term includes any
     successor Guarantor under the Indenture) and J.P. Morgan Trust Company,
     National Association, as Trustee (herein called the "Trustee", which term
     includes any successor trustee under the Indenture), and reference is
     hereby made to the Indenture for a statement of the respective rights,
     limitations of rights, duties and immunities thereunder of the Company, the
     Guarantor, the Trustee and the Holders of the Debt Securities and of the
     terms upon which the Debt Securities are, and are to be, authenticated and
     delivered.

              This Debt Security does not have the benefit of any sinking fund
     obligation.

              The Indenture contains provisions for defeasance at any time of
     the entire Indebtedness of this Debt Security or of certain restrictive
     covenants and Events of Default with respect to this Debt Security, in each
     case upon compliance with certain conditions set forth in the Indenture.

              If an Event of Default with respect to the Debt Securities of this
     series shall occur and be continuing, the principal of the Debt Securities
     of this series may be declared due and payable in the manner and with the
     effect provided in the Indenture.

              The Indenture permits, with certain exceptions as therein
     provided, the amendment thereof and the modification of the rights and
     obligations of the Company and/or the Guarantor and the rights of the
     Holders of the Debt Securities and/or the Guarantees of each series to be
     affected under the Indenture at any time by the Company, the Guarantor and
     the Trustee with the consent of the Holders of a majority in principal
     amount of the Debt Securities at the time Outstanding of each series to be
     affected. The Indenture also contains provisions permitting the Holders of
     specified percentages in principal amount of the Debt Securities of each
     series at the time Outstanding, on behalf of the Holders of all Debt
     Securities of such series, to waive compliance by the Company and/or the
     Guarantor with certain provisions of the Indenture and certain past
     defaults under the Indenture and their consequences. Any such consent or
     waiver by the Holder of this Debt Security shall be conclusive and binding
     upon such Holder and upon all future Holders of this Debt Security and of
     any Debt Security issued upon the registration of transfer hereof or in
     exchange herefor or in lieu hereof, whether or not notation of such consent
     or waiver is made upon this Debt Security.

              As provided in and subject to the provisions of the Indenture, the
     Holder of this Debt Security shall not have the right to institute any
     proceeding with respect to the Indenture or for the appointment of a
     receiver or trustee or for any other remedy thereunder, unless such Holder
     shall have previously given the Trustee written notice of a continuing
     Event of Default with respect to the Debt Securities of this series, the
     Holders of not less than 25% in principal amount of the Debt Securities of
     this series at the time Outstanding shall have made written request to the
     Trustee to institute proceedings in respect of such Event of Default as
     Trustee and offered the Trustee indemnity or security reasonably
     satisfactory to it, and the Trustee shall not have received from the
     Holders of a majority in principal amount of Debt Securities of this series
     at the time Outstanding a direction inconsistent with such request, and
     shall have failed to institute any such proceeding, for 60 days after
     receipt of such notice, request and offer of indemnity. The foregoing shall
     not apply to any suit instituted by the Holder of this Debt Security for
     the

<PAGE>

     enforcement of any payment of principal hereof or any premium or interest
     hereon on or after the respective due dates expressed herein.

              No reference herein to the Indenture and no provision of this Debt
     Security or of the Indenture shall alter or impair the obligation of the
     Company, which is absolute and unconditional, to pay the principal of and
     any interest on this Debt Security at the times, place and rate, and in the
     coin or currency, herein prescribed.

              As provided in the Indenture and subject to certain limitations
     therein set forth, the transfer of this Debt Security is registrable in the
     Security Register, upon surrender of this Debt Security for registration of
     transfer at the office or agency of the Company in any place where the
     principal of and any premium and interest on this Debt Security are
     payable, duly endorsed by, or accompanied by a written instrument of
     transfer in form satisfactory to the Company and the Security Registrar
     duly executed by, the Holder hereof or its attorney duly authorized in
     writing, and thereupon one or more new Debt Securities of this series and
     of like tenor, of authorized denominations and for the same aggregate
     principal amount, will be issued to the designated transferee or
     transferees.

              The Indenture and this Debt Security are governed by the laws of
     the State of New York, without regard to conflicts of laws provisions
     thereof.

              The Debt Securities of this series are issuable in registered form
     without coupons in denominations of $1,000 and any integral multiple
     thereof. As provided in the Indenture and subject to certain limitations
     therein set forth, Debt Securities of this series are exchangeable for a
     like aggregate principal amount of Debt Securities of this series and of
     like tenor of a different authorized denomination, as requested by the
     Holder surrendering the same.

              No service charge shall be made for any such registration of
     transfer or exchange, but the Company may require payment of a sum
     sufficient to cover any tax or other governmental charge payable in
     connection therewith.

              Prior to due presentment of this Debt Security for registration of
     transfer, the Company, the Guarantor, the Trustee and any agent thereof may
     treat the Person in whose name this Debt Security is registered as the
     owner hereof for all purposes, whether or not this Debt Security be
     overdue, and none of the Company, the Guarantor, the Trustee or any such
     agent shall be affected by notice to the contrary.

              All terms used in this Debt Security which are not defined herein
     and are defined in the Indenture shall have the meanings assigned to them
     in the Indenture.

<PAGE>

                                  GUARANTEE OF
                             BERKSHIRE HATHAWAY INC.

         FOR VALUE RECEIVED, Berkshire Hathaway Inc., a Delaware corporation
     (the "Guarantor"), hereby absolutely, unconditionally and irrevocably
     guarantees to the holders (the "Holders") of any security authenticated and
     delivered (each a "Security") by J.P. Morgan Trust Company, National
     Association, as trustee (the "Trustee") under that certain Indenture, dated
     as of December 22, 2003 (the "Indenture"), among the Trustee, the Guarantor
     and Berkshire Hathaway Finance Corporation, a Delaware corporation
     ("Issuer"), the full and prompt payment when due (whether at stated
     maturity, by acceleration or otherwise) of all present and future payment
     obligations of the Issuer pursuant to the terms of such Security and/or the
     Indenture, whether direct or indirect, absolute or contingent, and whether
     for principal, interest, fees, expenses, indemnification or otherwise
     (collectively, the "Obligations"). Nothing herein shall be deemed to
     guarantee any obligation of the Issuer other than the Obligations. Nothing
     herein shall be deemed to guarantee any obligation of any person or entity
     other than the Issuer.

         The Guarantor's obligations hereunder shall be unconditional and
     absolute, and shall not be released, discharged or otherwise affected by
     (i) the existence, validity, enforceability, perfection or extent of any
     collateral therefor, (ii) any lack of validity or enforceability of any
     provision of the Security or the Indenture, (iii) any liquidation,
     bankruptcy, insolvency, reorganization or other similar proceeding
     affecting the Issuer or its assets, or (iv) any other circumstance relating
     to the Obligations that might otherwise constitute a legal or equitable
     discharge of, or defense to, the Guarantor. The Guarantor agrees that the
     Holders and/or the Trustee may resort to the Guarantor, as primary obligor
     and not merely as surety, for payment of any of the Obligations whether or
     not the Holders or the Trustee shall have proceeded against the Issuer or
     any other obligor principally or secondarily obligated with respect to any
     of the Obligations. Neither the Holders nor the Trustee shall be obligated
     to file any claim relating to any of the Obligations in the event that the
     Issuer becomes subject to a bankruptcy, reorganization or similar
     proceeding, and the failure of the Holders or the Trustee to so file shall
     not affect the Guarantor's obligations hereunder. In the event that any
     payment to the Holders by the Issuer in respect of any Obligations is
     rescinded or must otherwise be returned for any reason whatsoever, the
     Guarantor shall remain liable hereunder with respect to such Obligations as
     if such payment had not been made.

         The Guarantor agrees that, subject to the Indenture, the Holders and/or
     the Trustee may at any time and from time to time, either before or after
     the maturity thereof, without notice to or further consent of the
     Guarantor, extend the time of payment of, exchange or surrender any
     collateral for, or renew any of the Obligations, and may also make any
     agreement with the Issuer or with any other party to or person liable on
     any of the Obligations or interested therein, for the extension, renewal,
     payment, compromise, discharge or release thereof, in whole or in part, or
     for any modification of the terms thereof or of any agreement between the
     Holders, the Trustee and the Issuer or any such other party or person, and
     that none of the foregoing shall in any way impair or affect this
     Guarantee. The Guarantor hereby unconditionally and irrevocably waives, to
     the fullest extent permitted by law, (a) notice of the acceptance of this
     Guarantee and of the Obligations, presentment, demand for payment, notice
     of dishonor and protest, (b) any requirement that any Holder exhaust any
     right or take any action against the Issuer, and (c) any right to revoke
     this Guarantee.

<PAGE>

         The Guarantor agrees to pay on demand all fees and out-of-pocket
     expenses incurred by the Holders or the Trustee in any way relating to the
     enforcement or protection of the rights of the Holders and/or the Trustee
     hereunder.

         Upon payment of any of the Obligations, the Guarantor shall be
     subrogated to the rights of the Holders and/or the Trustee against the
     Issuer with respect to such Obligations, and the Holders and the Trustee
     agree to take such steps, at the Guarantor's expense, as the Guarantor may
     reasonably request to implement such subrogation; provided, however, that
     the Guarantor shall not be entitled to enforce, or to receive any payments
     arising out of or based upon, such right of subrogation during any period
     in which any amount payable by the Issuer under the Security or the
     Indenture is overdue or unpaid.

         No failure on the part of the Holders or the Trustee to exercise, and
     no delay in exercising, any right, remedy or power hereunder shall operate
     as a waiver thereof, nor shall any single or partial exercise by the
     Holders or the Trustee of any right, remedy or power hereunder preclude any
     other or future exercise of any right, remedy or power. Each and every
     right, remedy and power hereby granted to the Holders or the Trustee or
     allowed any of them by law or other agreement shall be cumulative and not
     exclusive of any other, and may be exercised by the Holders or the Trustee
     at any time or from time to time.

         The Guarantor hereby represents and warrants that:

         (a) the Guarantor is duly organized, validly existing and in good
     standing as a corporation under the laws of the State of Delaware and has
     full corporate power to execute, deliver and perform this Guarantee;

         (b) the execution, delivery and performance of this Guarantee have been
     and remain duly authorized by all necessary corporate action and do not
     contravene any provision of the Guarantor's certificate of incorporation or
     by-laws, as amended to date, or any law, regulation, rule, decree, order,
     judgment or contractual restriction binding on the Guarantor or its assets;

         (c) all consents, licenses, clearances, authorizations and approvals
     of, and registrations and declarations with, any governmental authority or
     regulatory body necessary for the due execution, delivery and performance
     of this Guarantee have been obtained and remain in full force and effect
     and all conditions thereof have been duly complied with, and no other
     action by, and no notice to or filing with, any governmental authority or
     regulatory body is required in connection with the execution, delivery or
     performance of this Guarantee;

         (d) this Guarantee constitutes a legal, valid and binding obligation of
     the Guarantor enforceable against the Guarantor in accordance with its
     terms, subject to bankruptcy, insolvency, reorganization, moratorium and
     other laws of general applicability relating to or affecting creditors'
     rights and to general equity principles; and

         (e) there are no actions, suits or arbitration proceedings pending or,
     to the knowledge of the Guarantor, threatened against it, at law or in
     equity, which, individually or in the aggregate, if adversely determined,
     would materially adversely affect the financial condition of the Guarantor
     or materially impair its ability to perform its obligations under this
     Guarantee.

         The Guarantor may not assign its obligations hereunder to any person
     (except as permitted by the Indenture) without the prior written consent of
     the Holders or the Trustee.

<PAGE>

         All payments by the Guarantor to the Holders or the Trustee shall be
     made in accordance with the provisions of the Indenture and the Security;
     provided, however, that payment of any fees or expenses pursuant to the
     fourth paragraph hereof shall be made by wire transfer of immediately
     available funds to an account at a commercial bank in the United States
     specified to the Guarantor at least ten (10) days in advance of any demand
     for payment by the Holders or the Trustee.

         All notices or demands on the Guarantor shall be deemed effective when
     received, shall be in writing and shall be delivered by hand or by
     registered mail, or by facsimile transmission promptly confirmed by
     registered mail, addressed to the Guarantor at:

                  Berkshire Hathaway Inc.
                  1440 Kiewit Plaza
                  Omaha, NE 68131
                  Attention:  Chief Financial Officer
                  Facsimile:  (402) 346-3375

     or to such other addresses or facsimile numbers as the Guarantor shall have
     notified the Holders or the Trustee in a written notice delivered in
     accordance with the Indenture.

         This Guarantee shall remain in full force and effect and shall be
     binding on the Guarantor, its successors and assigns until all of the
     Obligations have been satisfied in full.

         This Guarantee shall be governed by, and construed in accordance with,
     the laws of the State of New York applicable to contracts made and to be
     performed solely within such State.

     No amendment or waiver of any provision of this Guarantee shall in any
     event be effective unless the same shall be in writing and signed by the
     Trustee and the Guarantor.

     If for any reason any provision or provisions hereof are determined to be
     invalid and contrary to any existing or future law, such invalidity shall
     not, to the fullest extent permitted by law, impair the operation of or
     effect of those portions of this Guarantee that are valid.

         THE GUARANTOR WAIVES ANY RIGHT IT MAY HAVE TO A JURY TRIAL IN
     CONNECTION WITH ANY ACTION, SUIT OR PROCEEDING ARISING OUT OF OR RELATED IN
     ANY WAY TO THIS GUARANTEE.

<PAGE>

Dated: _________                            BERKSHIRE HATHAWAY INC.

                                            By:________________________
                                               Name:  Marc D. Hamburg
                                               Title: Chief Financial Officer

<PAGE>

             SCHEDULE OF INCREASES OR DECREASES IN GLOBAL SECURITY

     The following increases or decreases in this Debt Security have been made:

<TABLE>
<CAPTION>
                   Amount of decrease in   Amount of increase in    Principal amount of this   Signature of authorized
                    principal amount of   principal amount of this   Debt Security following   signatory of Trustee or
 Date of exchange   this Debt Security         Debt Security        such decrease or increase     Security Custodian
 ----------------  ---------------------  ------------------------  -------------------------  -----------------------
<S>                <C>                    <C>                       <C>                        <C>
</TABLE>

<PAGE>

                                   ASSIGNMENT

         FOR VALUE RECEIVED, the undersigned assigns and transfers this Debt
     Security to:

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

     ---------------------------------------------------------------------------
         (Insert assignee's social security or tax identification number)

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

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

     ---------------------------------------------------------------------------
                   (Insert address and zip code of assignee)

     and irrevocably appoints _______ as agent to transfer this Debt Security on
     the Security Register. The agent may substitute another to act for him or
     her.

         Dated:                    Signature:

                              Signature Guarantee:

          (Sign exactly as your name appears on the other side of this
                                 Debt Security)

              Signatures must be guaranteed by an "eligible guarantor
     institution" meeting the requirements of the Security Registrar, which
     requirements include membership or participation in the Security Transfer
     Agent Medallion Program ("STAMP") or such other "signature guarantee
     program" as may be determined by the Security Registrar in addition to, or
     in substitution for, STAMP, all in accordance with the Securities Exchange
     Act of 1934, as amended.