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EXHIBIT 12

Chief Executive Officer Certification

I, David V. Murray, Chief Executive Officer, certify that:



|1. |  | I have reviewed this annual report on Form 20-F of Commonwealth Bank of
Australia;                                                                                                                                                                                                                        
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|  
|2. |  | Based on my knowledge, this report 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 with respect to the period covered by this
report;
|  
|3. |  | Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material
respects the financial condition, results of operations and cash flows of
the company as of, and for, the periods presented in this report;                      
|  
|4. |  | The companys other certifying officer(s) and I are responsible for
establishing and maintaining disclosure controls and procedures (as
defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the company and
have:                                                                                  



| | a. |  | Designed such disclosure controls and procedures, or caused such
disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the
company, including its consolidated subsidiaries, is made known to us
by others within those entities, particularly during the period in
which this report is being prepared;
| | -- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | b. |  | [Omitted pursuant to the guidance of SEC Release No. 33-8238 (June
5, 2003)]                                                                                                                                                                                                                                                                                               
|
| | c. |  | Evaluated the effectiveness of the companys disclosure controls
and procedures and presented in this report our conclusions about the
effectiveness of the disclosure controls and procedures, as of the end
of the period covered by this report based on such evaluation; and                                                                                           
|
| | d. |  | Disclosed in this report any change in the companys internal
control over financial reporting that occurred during the period
covered by the annual report that has materially affected, or is
reasonably likely to materially affect, the companys internal control
over financial reporting; and                                                                       



|5. |  | The companys other certifying officer(s) and I have disclosed, based on
our most recent evaluation of internal control over financial reporting,
to the companys auditors and the audit committee of the companys board
of directors (or persons performing the equivalent functions):
|-- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | a. |  | All significant deficiencies and material weaknesses in the design
or operation of internal control over financial reporting which are
reasonably likely to adversely affect the companys ability to record,
process, summarize and report financial information; and
| | -- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | b. |  | Any fraud, whether or not material, that involves management or
other employees who have a significant role in the companys internal
control over financial reporting.                                                                                               

Date: 20 November 2003

/s/  David V. Murray




Name: David V. Murray
Title: Managing Director and Chief Executive Officer





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##### 



Chief Financial Officer Certification

I, Michael Cameron, Chief Financial Officer, certify that:



|1. |  | I have reviewed this annual report on Form 20-F of Commonwealth Bank of
Australia;                                                                                                                                                                                                                        
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|  
|2. |  | Based on my knowledge, this report 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 with respect to the period covered by this
report;
|  
|3. |  | Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material
respects the financial condition, results of operations and cash flows of
the company as of, and for, the periods presented in this report;                      
|  
|4. |  | The companys other certifying officer(s) and I are responsible for
establishing and maintaining disclosure controls and procedures (as
defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the company and
have:                                                                                  



| | a. |  | Designed such disclosure controls and procedures, or caused such
disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the
company, including its consolidated subsidiaries, is made known to us
by others within those entities, particularly during the period in
which this report is being prepared;
| | -- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | b. |  | [Omitted pursuant to the guidance of SEC Release No. 33-8238 (June
5, 2003)]                                                                                                                                                                                                                                                                                               
|
| | c. |  | Evaluated the effectiveness of the companys disclosure controls
and procedures and presented in this report our conclusions about the
effectiveness of the disclosure controls and procedures, as of the end
of the period covered by this report based on such evaluation; and                                                                                           
|
| | d. |  | Disclosed in this report any change in the companys internal
control over financial reporting that occurred during the period
covered by the annual report that has materially affected, or is
reasonably likely to materially affect, the companys internal control
over financial reporting; and                                                                       



|5. |  | The companys other certifying officer(s) and I have disclosed, based on
our most recent evaluation of internal control over financial reporting,
to the companys auditors and the audit committee of the companys board
of directors (or persons performing the equivalent functions):
|-- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | a. |  | All significant deficiencies and material weaknesses in the design
or operation of internal control over financial reporting which are
reasonably likely to adversely affect the companys ability to record,
process, summarize and report financial information; and
| | -- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | b. |  | Any fraud, whether or not material, that involves management or
other employees who have a significant role in the companys internal
control over financial reporting.                                                                                               

Date: 20 November 2003

/s/  Michael Cameron




Name: Michael Cameron
Title: Chief Financial Officer