Exhibit 31.1

**CERTIFICATION**

I, John J. Sims, certify that:

| 1.     | I have reviewed this quarterly report on Form 10-Q of 724 Solutions   Inc.;                                                                                                                                                                                                                                             |
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| 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;      |
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| 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   registrant as of, and for, the periods presented in this report;                           |
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| 4.     | The registrant’s other certifying officers 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 registrant and have:                                                                                   |
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|   | 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 registrant, 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; |
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|   | b)                                                                                                                                                                                                                                                                                                                      | Evaluated the effectiveness of the registrant’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 |
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|   | c)                                                                                                                                                                                                                                                                                                                      | Disclosed in this report any change in the registrant’s internal   control over financial reporting that occurred during the registrant’s most   recent fiscal quarter that has materially affected, or is reasonably likely   to materially affect, the registrant’s internal control over financial   reporting; and |
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| 5.     | The registrant’s other certifying officers and I have disclosed,   based on our most recent evaluation of internal control over financial   reporting, to the registrant’s auditors and the audit committee of the   registrant’s board of directors (or persons performing the equivalent   functions): |
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|   | 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 registrant’s ability to record, process,   summarize and report financial information; and |
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|   | b)                                                                                                                                                                                                                                                                                                                      | Any fraud, whether or not material, that involves management or other   employees who have a significant role in the registrant’s internal control   over financial reporting. |

Date:  August 12, 2005

|   | /s/   JOHN J. SIMS        |
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|   | John J. Sims              |
|   | Chief   Executive Officer |