<PAGE>

================================================================================
                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   FORM 10-K/A

[X]   ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
      EXCHANGE ACT OF 1934

FOR THE FISCAL YEAR ENDED: DECEMBER 31, 2004 OR

[ ]   TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES ACT OF
      1934

FOR THE TRANSITION PERIOD FROM __________ TO _________.

COMMISSION FILE NUMBER: 333-115296-03

SEQUOIA RESIDENTIAL FUNDING, INC. (AS DEPOSITOR UNDER THE POOLING AND SERVICING
AGREEMENT, DATED JUNE 1, 2004, PROVIDING FOR THE ISSUANCE OF THE SEQUOIA
MORTGAGE TRUST 2004-6, MORTGAGE PASS-THROUGH CERTIFICATES)

                  SEQUOIA RESIDENTIAL FUNDING, INC.
       (Exact Name of registrant as specified in its charter)

                    DELAWARE                                 35-2170972
(State or other jurisdiction of incorporation    (I.R.S. employer identification
               or organization)                                 no.)

               ONE BELVEDERE PLACE
                    SUITE 330
                 MILL VALLEY, CA                               94941
    (Address of principal executive offices)                 (Zip code)

                                 (415) 389-7373
              (Registrant's telephone number, including area code)

 Securities registered pursuant to          Securities registered pursuant to
   Section 12(b) of the Act:                   Section 12(g) of the Act:

                NONE                                    NONE
           (Title of class)                       (Title of class)

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the Registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days. Yes [ X ] No [ ]

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of Registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [ X ]

Indicate by check mark whether the Registrant is an accelerated filer (as
defined in Exchange Act Rule 12b-2). Yes [ ] No [ X ]

State the aggregate market value of the voting stock held by non-affiliates of
Registrant. The aggregate market value shall be computed by reference to the
price at which the stock was sold, or the average bid and asked prices of such
stock, as of the last business day of the Registrant's most recently completed
second fiscal quarter:

                                 NOT APPLICABLE

                      Documents incorporated by reference:

                                 NOT APPLICABLE
================================================================================

<PAGE>

                        SEQUOIA RESIDENTIAL FUNDING, INC.
        SEQUOIA MORTGAGE TRUST 2004-6, MORTGAGE PASS-THROUGH CERTIFICATES

                                      INDEX

<TABLE>
<CAPTION>
                                                                                                                        Page
                                                                                                                        ----
<S>           <C>                                                                                                       <C>
PART I        ........................................................................................................   3
              ITEM 1     -   BUSINESS.................................................................................   3
              ITEM 2     -   PROPERTIES...............................................................................   3
              ITEM 3     -   LEGAL PROCEEDINGS........................................................................   3
              ITEM 4     -   SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS......................................   3

PART II       ........................................................................................................   3
              ITEM 5     -   MARKET FOR REGISTRANT'S COMMON STOCK, RELATED STOCKHOLDER
                             MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES........................................   3
              ITEM 6     -   SELECTED FINANCIAL DATA..................................................................   3
              ITEM 7     -   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS....   3
              ITEM 7A    -   QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK...............................   3
              ITEM 8     -   FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA..............................................   3
              ITEM 9     -   CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE.....   3
              ITEM 9A    -   CONTROLS AND PROCEDURES..................................................................   4
              ITEM 9B    -   OTHER INFORMATION........................................................................   4

PART III      ........................................................................................................   4
              ITEM 10    -   DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT.......................................   4
              ITEM 11    -   EXECUTIVE COMPENSATION...................................................................   4
              ITEM 12    -   SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT...........................   4
              ITEM 13    -   CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS...........................................   6
              ITEM 14    -   PRINCIPAL ACCOUNTANT FEES AND SERVICES...................................................   6

PART IV       ........................................................................................................   6
              ITEM 15    -   EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K..........................   6

SIGNATURES    ........................................................................................................   8

CERTIFICATION ........................................................................................................   9

SUPPLEMENTAL INFORMATION TO BE FURNISHED WITH REPORTS FILED PURSUANT TO SECTION 15(d) OF THE ACT BY REGISTRANTS WHICH
HAVE NOT REGISTERED SECURITIES PURSUANT TO SECTION 12 OF THE ACT......................................................  10

INDEX TO EXHIBITS ....................................................................................................  10
</TABLE>

                                       2
<PAGE>

                                     PART I

ITEM 1   -  BUSINESS

            Not Applicable.

ITEM 2   -  PROPERTIES

            Sequoia Residential Funding, Inc. (the "Depositor") will furnish
information regarding the Mortgaged Properties by reference to the Annual
Compliance Certificates to be filed herein under Item 15.

ITEM 3   -  LEGAL PROCEEDINGS

            The Depositor is not aware of any material pending legal proceedings
involving either the Mortgage Pass-Through Certificates, the Sequoia Mortgage
2004-6 Trust (the "Trust); the Pooling and Servicing Agreement; the Trustee; the
Depositor; the Seller; the Master Servicer or the Servicers which relates to the
Trust.

ITEM 4   -  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

            No matter has been submitted to a vote of the holders of beneficial
interests in the Trust through the solicitation of proxies or otherwise.

                                     PART II

ITEM 5   -  MARKET FOR REGISTRANT'S COMMON STOCK, RELATED STOCKHOLDER MATTERS
            AND ISSUER PURCHASES OF EQUITY SECURITES

            To the best knowledge of the Depositor, there is no established
public trading market for the Certificates.

            The Certificates issued by the Trust are held by the Depository
Trust Company ("DTC") which in turn maintains records of holders of beneficial
interests in the Certificates. Based on information obtained by the Trust from
DTC, as of December 31, 2004, there were ten (10) holders of the Class A-1
Certificates, three (3) holders of the Class A-2 Certificates, five (5) holders
of the Class A-3-A Certificates, two (2) holders of the Class X-3-B
Certificates, three (3) holders of the Class X-A Certificates, one (1) holder of
the Class X-B Certificates, three (3) holders of the Class B-1 Certificates, two
(2) holders of the Class B-2 Certificates, and one (1) holder of the Class B-3
Certificates.

ITEM 6   -  SELECTED FINANCIAL DATA

            Not Applicable.

ITEM 7   -  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
            RESULTS OF OPERATIONS

            Not Applicable.

ITEM 7A  -  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

            Not Applicable.

ITEM 8   -  FINANCIAL STATEMENTS AND SUPPLEMENTARY INFORMATION

            Not Applicable.

ITEM 9   -  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
            FINANCIAL DISCLOSURE

            There were no changes of accountants or disagreements on accounting
or financial disclosures between the Depositor and its accountants.

                                       3
<PAGE>

ITEM 9A  -  CONTROLS AND PROCEDURES

            Not Applicable.

ITEM 9B  -  OTHER INFORMATION

            Not Applicable.

                                    PART III

ITEM 10  -  DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

            Not Applicable.

ITEM 11  -  EXECUTIVE COMPENSATION

            Not Applicable.

ITEM 12  -  SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

            The Depositor is a Delaware corporation and indirect wholly-owned
subsidiary of Redwood Trust, Inc. The Trust is a grantor trust established under
the Pooling and Servicing Agreement.

            The following table sets forth (i) the identification of each entity
owning more than 5% of the outstanding principal amount of each class of the
Pass-Through Certificates; (ii) the principal amount of each class of the
Pass-Through Certificates owned by each and (iii) the percent that the principal
amount of each class of the Pass-Through Certificates owned by such entity
represents of the outstanding principal amount of such class of Pass-Through
Certificates. The information set forth in the table for the Certificates is
based upon information obtained by the Trust from DTC and represents ownership
of beneficial interest in the Certificates held by DTC. The Depositor is not
aware of any Schedules 13D or 13G filed with the Securities and Exchange
Commission in respect of the Certificates.

CLASS A-1

<TABLE>
<CAPTION>
Identification      Principal Amount Owned      Percentage of Outstanding Amount
--------------      ----------------------      --------------------------------
<S>                 <C>                         <C>
BANK OF NY                  $159,310,000                     31.86%
ML SFKPG                    $150,000,000                        30%

BNY/CDC-FP                  $ 70,000,000                        14%
MELLON TR                   $$54,700,000                     10.94%

SSB&T CO                    $ 45,270,000                      9.05%
</TABLE>

CLASS A-2

<TABLE>
<CAPTION>
Identification       Principal Amount Owned     Percentage of Outstanding Amount
--------------       ----------------------     --------------------------------
<S>                  <C>                        <C>
CITIBANK                     $$47,687,000                    25.68%
MELLON TR                    $ 25,000,000                    13.46%
SSB&T CO                     $113,000,000                    60.85%
</TABLE>

                                       4
<PAGE>

CLASS A-3-A

<TABLE>
<CAPTION>
Identification        Principal Amount Owned    Percentage of Outstanding Amount
--------------        ----------------------    --------------------------------
<S>                   <C>                       <C>
BANK OF NY                  $ 12,300,000                       6.26%
CITIBANK                    $126,000,000                      64.12%
SSB&T CO                    $ 35,000,000                      17.81%
JPMCBNA                     $ 21,700,000                      11.04%
</TABLE>

CLASS X-3-B

<TABLE>
<CAPTION>
Identification        Principal Amount Owned    Percentage of Outstanding Amount
--------------        ----------------------    --------------------------------
<S>                   <C>                       <C>
CITIBANK                    $2,000,000                     57.14%

JPMCBNA                     $1,500,000                     42.86%
</TABLE>

CLASS X-A

<TABLE>
<CAPTION>
Identification        Principal Amount Owned     Percentage of Outstanding Amount
--------------        ----------------------     --------------------------------
<S>                   <C>                        <C>
BANK OF NY                  $ 46,272,000                        12%
MERRIL                      $192,843,500                        50%
NRTHRN TR                   $146,571,500                        38%
</TABLE>

CLASS X-B

<TABLE>
<CAPTION>
Identification       Principal Amount Owned     Percentage of Outstanding Amount
--------------       ----------------------     --------------------------------
<S>                  <C>                        <C>
CITIBANK                  $24,975,000                        100%
</TABLE>

CLASS B-1

<TABLE>
<CAPTION>
Identification       Principal Amount Owned     Percentage of Outstanding Amount
--------------       ----------------------     --------------------------------
<S>                  <C>                        <C>
JPMC/RBS                  $8,725,000                       55.48%
JPMCBNA                   $4,000,000                       25.44%
LASALLE BK                $3,000,000                       19.08%
</TABLE>

CLASS B-2

<TABLE>
<CAPTION>
Identification       Principal Amount Owned     Percentage of Outstanding Amount
--------------       ----------------------     --------------------------------
<S>                  <C>                        <C>
JPMCBNA                   $5,250,000                         56.76%
WELLS BKNA                $4,000,000                         43.24%
</TABLE>

CLASS B-3

<TABLE>
<CAPTION>
Identification      Principal Amount Owned      Percentage of Outstanding Amount
--------------      ----------------------      --------------------------------
<S>                 <C>                         <C>
WELLS BKNA                $5,550,000                          100%
</TABLE>

                                       5
<PAGE>

ITEM 13  -  CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

            None.

ITEM 14     PRINCIPAL ACCOUNTANT FEES AND SERVICES

            Not Applicable.

                                     PART IV

ITEM 15  -  EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

            (a)   The following documents are filed as part of this report:

                  1.    Financial Statements:

                        Not applicable.

                  2.    Financial Statement Schedules:

                        Not applicable.

                  3.    Exhibits:

<TABLE>
<CAPTION>
Exhibit No.          Description
-----------          -----------
<S>                  <C>
31.1                 Sarbanes-Oxley Certification.

99.1                 Statement of Compliance of the Servicer pursuant to Section 7.04(a) of
                     The Master Servicing Agreement between RWT Holdings, Inc. ("RWT") and
                     Morgan Stanley Dean Witter Credit Corporation, dated August 1, 2002,
                     as modified by the related Acknowledgements (the "RWT/Morgan Servicing
                     Agreement").

99.2                 Report of Independent Accountant pursuant to Section 7.04(b) of the
                     RWT/Morgan Servicing Agreement.

99.3                 Statement of Compliance of the Servicer pursuant to Section 6.04 of
                     The Mortgage Loan Flow Purchase, Sale and Servicing Agreement, dated
                     as of August 1, 2002, between RWT and GreenPoint Mortgage Funding,
                     Inc., as modified by the related Acknowledgements (the "RWT/GreenPoint
                     Servicing Agreement").

99.4                 Report of Independent Account pursuant to Section 6.05 of the
                     RWT/GreenPoint Servicing Agreement.

99.5                 Statement of Compliance of the Servicer pursuant to Section 7.04 of
                     The Mortgage Loan Flow Purchase, Sale & Servicing Agreement among RWT,
                     Cendant Mortgage Corporation ("Cendant") and Bishop's Gate Residential
                     Mortgage Trust (formerly known as Cendant Residential Mortgage Trust),
                     as Sellers, and Cendant, as Servicer, dated August 1, 2002, as
                     modified by the related Acknowledgements (the "RWT/Cendant Servicing
                     Agreement").

99.6                 Report of Independent Accountant pursuant to Section 7.05 of the
                     RWT/Cendant Servicing Agreement.
</TABLE>

                                       6
<PAGE>

<TABLE>
<S>                  <C>
99.7                 Statement of Compliance of the Servicer pursuant to Section 11.20 of
                     the Flow Mortgage Loan Sale and Servicing Agreement, dated as of April
                     1, 2003, between RWT and Bank of America, N.A., as modified by the
                     related Acknowledgements (the "RWT/Bank of America Servicing
                     Agreement").

99.8                 Report of Independent Accountant pursuant to Section 11.21 of the
                     RWT/Bank of America Servicing Agreement.

99.9                 Statement of Compliance of the Servicer pursuant to Section 6.04 of
                     the Loan Servicing Agreement, dated as of February 1, 2004 between RWT
                     and GMAC Mortgage Corporation, as modified by the related
                     Acknowledgements (the "RWT/GMAC Servicing Agreement").

99.10                Report of Independent Accountant pursuant to Section 6.05 of the
                     RWT/GMAC Servicing Agreement.

99.11                Statement of Compliance of the Servicer pursuant to Section 5.04 of
                     the Mortgage Loan Purchase and Servicing Agreement, dated as of April
                     1, 1998, between RWT and Countrywide Home Loans, Inc., as amended by
                     the Amendment Number One to such agreement, dated February 27, 2004,
                     as modified by the related Acknowledgements (the "RWT/Countrywide
                     Servicing Agreement").

99.12                Report of Independent Accountant pursuant to Section 5.05 of the
                     RWT/Countrywide Servicing Agreement.
</TABLE>

      (b)   Reports on Form 8-K field during the last quarter of the period
            covered by this report.

<TABLE>
<CAPTION>
DATE OF REPORTS ON FORM 8-K               ITEMS REPORTED/FINANCIAL STATEMENTS FILED
<S>                              <C>
June 29, 2004                    Report filing Computational Materials and Collateral Term Sheet

July 14, 2004                    Report filing the Pooling and Servicing Agreement and the
                                 Tax Opinion

August 2, 2004                   Trustee's Monthly Report for the July Distribution to
                                 Certificateholders

September 3, 2004                Trustee's Monthly Report for the August Distribution to
                                 Certificateholders

October 6, 2004                  Trustee's Monthly Report for the September Distribution to
                                 Certificateholders

November 5, 2004                 Trustee's Monthly Report for the October Distribution to
                                 Certificateholders

December 3, 2004                 Trustee's Monthly Report for the November Distribution to
                                 Certificateholders

January 5, 2005                  Trustee's Monthly Report for the December Distribution to
                                 Certificateholders
</TABLE>

                                       7
<PAGE>

                                   SIGNATURES

      Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Depositor has duly caused this Report to be signed on
its behalf by the undersigned, thereunto duly authorized.

                                    SEQUOIA RESIDENTIAL FUNDING, INC.

                                    By: /s/ Harold F. Zagunis
                                        ----------------------------------------
                                    Name: Harold F. Zagunis
                                    Title: Chief Financial Officer and Secretary

Date: May 31, 2005.

                                       8
<PAGE>

                                  CERTIFICATION

      I, Harold F. Zagunis, Chief Financial Officer and Secretary of Sequoia
Residential Funding, Inc., a Delaware corporation, hereby certify that:

      1.    I have reviewed this annual report on Form 10-K/A, and all reports
on Form 8-K containing distribution or servicing reports filed in respect of the
Certificates for periods included in the year covered by this annual report, of
Sequoia Residential Funding, Inc.;

      2.    Based on my knowledge, the information in these reports, taken as a
whole, does not contain any untrue statement of a material fact or omit to state
a material fact necessary to make the statements made, in light of the
circumstances under which such statements were made, not misleading as of the
last day of the period covered by this annual report;

      3.    Based on my knowledge, the distribution or servicing information
required to be provided to the trustee by the servicer under the pooling and
servicing agreement, for inclusion in these reports is included in these
reports;

      4.    Based on my knowledge and upon the annual compliance statement
included in the report and required to be delivered to the trustee in accordance
with the terms of the pooling and servicing agreement, and except as disclosed
in the reports, the servicer has fulfilled its obligations under the servicing
agreement; and

      5.    The reports disclose all significant deficiencies relating to the
servicer's compliance with the minimum servicing standards based upon the report
provided by an independent public accountant, after conducting a review in
compliance with the Uniform Attestation Program for Mortgage Bankers or similar
procedure, as set forth in the pooling and servicing agreement, that is included
in these reports.

      In giving the certifications above, I have reasonably relied on
information provided to me by the following unaffiliated parties: Morgan Stanley
Dean Witter Credit Corporation, as Servicer, GreenPoint Mortgage Funding, Inc.,
as Servicer, Cendant Mortgage Corporation, as Servicer, Bank of America, N.A.,
as Servicer, GMAC Mortgage Corporation, as Servicer, and Countrywide Home Loans,
Inc., as Servicer.

Date: May 31, 2005

/s/ Harold F. Zagunis
--------------------------------------------
Signature
Name: Harold F. Zagunis
Title: Chief Financial Officer and Secretary

                                       9
<PAGE>

SUPPLEMENTAL INFORMATION TO BE FURNISHED WITH REPORTS FILED PURSUANT TO SECTION
15(d) OF THE ACT BY REGISTRANTS WHICH HAVE NOT REGISTERED SECURITIES PURSUANT TO
SECTION 12 OF THE ACT.

      No annual report, proxy statement, proxy materials or otherwise were sent
to Certificateholders.

                                INDEX TO EXHIBITS
                                   Item 15(C)

<TABLE>
<CAPTION>
Exhibit No.      Description
-----------      -----------
<S>              <C>
31.1             Sarbanes-Oxley Certification

99.1             Statement of Compliance of the Servicer pursuant to Section 7.04(a) of The Master Servicing
                 Agreement between RWT Holdings, Inc. ("RWT") and Morgan Stanley Dean Witter Credit Corporation, dated August
                 1, 2002, as modified by the related Acknowledgements (the "RWT/ Morgan Servicing Agreement").

99.2             Report of Independent Accountant pursuant to Section 7.04(b) of  the RWT/Morgan Servicing Agreement.

99.3             Statement of Compliance of the Servicer pursuant to Section 6.04 of The Mortgage Loan Flow Purchase, Sale and
                 Servicing Agreement, dated as of August 1, 2002, between RWT and GreenPoint Mortgage Funding, Inc., as
                 modified by the related Acknowledgements (the "RWT/GreenPoint Servicing Agreement").

99.4             Report of Independent Account pursuant to Section 6.05 of RWT/GreenPoint Servicing Agreement.

99.5             Statement of Compliance of the Servicer pursuant to Section 7.04 of The Mortgage Loan Flow Purchase, Sale &
                 Servicing Agreement among RWT, Cendant Mortgage Corporation ("Cendant") and Bishop's Gate Residential
                 Mortgage Trust (formerly known as Cendant Residential Mortgage Trust), as Sellers, and Cendant, as Servicer,
                 dated August 1, 2002, as modified by the related Acknowledgements (the "RWT/Cendant Servicing Agreement").

99.6             Report of Independent Accountant pursuant to Section 7.05 of the RWT/Cendant Servicing
                 Agreement.

99.7             Statement of Compliance of the Servicer pursuant to Section 11.20 of the Flow Mortgage Loan Sale and
                 Servicing Agreement, dated as of April 1, 2003, between RWT and Bank of America, N.A., as modified by the
                 related Acknowledgements (the "RWT/Bank of America Servicing Agreement").

99.8             Report of Independent Accountant pursuant to Section 11.21 of the RWT/Bank of America Servicing Agreement.

99.9             Statement of Compliance of the Servicer pursuant to Section 6.04 of the Loan Servicing Agreement, dated as of
                 February 1, 2004, between RWT and GMAC Mortgage Corporation, as modified by the related Acknowledgements (the
                 "RWT/GMAC Servicing Agreement").
</TABLE>

                                       10
<PAGE>

<TABLE>
<S>              <C>
99.10            Report of Independent Accountant pursuant to Section 6.05 of the RWT/GMAC Servicing Agreement.

99.11            Statement of Compliance of the Servicer pursuant to Section 5.04 of the Mortgage Loan Purchase and Servicing
                 Agreement, dated as of April 1, 1998, between RWT and Countrywide Home Loans, Inc., as amended by the
                 Amendment Number One to such agreement, dated February 27, 2004, as modified by the related Acknowledgements
                 (the "RWT/Countrywide Servicing Agreement").

99.12            Report of Independent Accountant pursuant to Section 5.05 of the RWT/Countrywide Servicing Agreement.
</TABLE>

                                       11