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SECURITIES AND EXCHANGE COMMISSION


Washington, D.C. 20549





Form 10-K/A


|    |  |                                                                                             
|--- |  | --------------------------------------------------------------------------------------------
|þ   |  | 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,
|   
|o   |  | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
    SECURITIES EXCHANGE ACT OF 1934
|   
|    |  | FOR THE TRANSITION PERIOD
    FROM          TO                                              

Commission file number 0-27012





Insignia Solutions plc


(Exact name of Registrant as specified in its charter)


|                                                                   |  |                                            
|------------------------------------------------------------------ |  | -------------------------------------------
|England and Wales                                                  |  | Not applicable                             
|(State or other jurisdiction of
    incorporation or organization) |  | (I.R.S. employer
    identification number)




|                                                                                                           |  |                                                                                                                                               
|---------------------------------------------------------------------------------------------------------- |  | ----------------------------------------------------------------------------------------------------------------------------------------------
|41300 Christy Street
    Fremont
    California 94538-3115
    United States of America
    (510) 360-3700 |  | Insignia House
    The Mercury Centre
    Wycombe Lane, Wooburn Green
    High Wycombe, Bucks HP10 0HH
    United Kingdom
    (44) 1628-539500

(Address and telephone number of principal executive offices
and principal places of business)


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


None


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


(Title of class)


Ordinary Shares (£0.20 nominal value)


o þ


o


o þ














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TABLE OF CONTENTS



|                                   |  |  |  |  |  |  |  | 
|---------------------------------- |  |  |  |  |  |  |  | 
|Item 9A -- Controls and Procedures
|EXHIBIT 31.01                     
|EXHIBIT 31.02                     
|EXHIBIT 32.01                     
|EXHIBIT 32.02                     



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EXPLANATORY NOTE








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PART II







|          |                        
|--------- | -----------------------
|Item 9A  | Controls and Procedures

Evaluation of Disclosure Controls and Procedures.


Internal Control Over Financial Reporting.


PART IV




|          |         
|--------- | --------
|Item 15  | Exhibits

|        |    |               |  |                                                                                                                                                           
|------- | -- | ------------- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------
|Exhibit |    |              
|Number  |    | Exhibit Title
|        |    |              
|        | 31 | .01           |  | Certification of Chief Executive Officer pursuant to
    Section 302 of the Sarbanes-Oxley Act of 2002.                                                   
|        | 31 | .02           |  | Certification of Chief Financial Officer pursuant to
    Section 302 of the Sarbanes-Oxley Act of 2002.                                                   
|        | 32 | .01           |  | Certification of Chief Executive Officer pursuant to 18 U.S.C.
    Section 1350, as adopted pursuant to Section 906 of
    the Sarbanes-Oxley Act of 2002.
|        | 32 | .02           |  | Certification of Chief Financial Officer pursuant to 18 U.S.C.
    Section 1350, as adopted pursuant to Section 906 of
    the Sarbanes-Oxley Act of 2002.

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SIGNATURES






| |                       
| | ----------------------
| | INSIGNIA SOLUTIONS PLC



| |     |                     
| | --- | --------------------
| | By: | /s/ Mark E. McMillan

| |                        
| | -----------------------
| |                        
| | Mark E. McMillan       
| | Chief Executive Officer

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EXHIBIT INDEX


|        |    |               |  |                                                                                                                                                           
|------- | -- | ------------- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------
|Exhibit |    |              
|Number  |    | Exhibit Title
|        |    |              
|        | 31 | .01           |  | Certification of Chief Executive Officer pursuant to
    Section 302 of the Sarbanes-Oxley Act of 2002.                                                   
|        | 31 | .02           |  | Certification of Chief Financial Officer pursuant to
    Section 302 of the Sarbanes-Oxley Act of 2002.                                                   
|        | 32 | .01           |  | Certification of Chief Executive Officer pursuant to 18 U.S.C.
    Section 1350, as adopted pursuant to Section 906 of
    the Sarbanes-Oxley Act of 2002.
|        | 32 | .02           |  | Certification of Chief Financial Officer pursuant to 18 U.S.C.
    Section 1350, as adopted pursuant to Section 906 of
    the Sarbanes-Oxley Act of 2002.

3