SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K/A REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2003 COMMISSION FILE No. 1-31690 TRANSCANADA CORPORATION (TRANSLATION OF REGISTRANT'S NAME INTO ENGLISH) 450 - 1 STREET S.W., CALGARY, ALBERTA, T2P 5H1, CANADA (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES) (Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F) Form 20-F Form 40-F X ----- ----- (Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.) Yes No X ----- ----- TransCanada Corporation is filing this Form 6-K/A for the purpose of filing the attached Exhibits 7 and 8, which shall replace in their entirety Exhibits 7 and 8 to the report on Form 6-K filed on July 28, 2003.

SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. TRANSCANADA CORPORATION By: /s/ Russell K. Girling --------------------------------------- Russell K. Girling Executive Vice-President, Corporate Development and Chief Financial Officer By: /s/ Lee G. Hobbs --------------------------------------- Lee G. Hobbs Controller August 14, 2003

EXHIBIT INDEX 7 Certification of Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act. 8 Certification of Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act.

EXHIBIT 7 CERTIFICATE PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT I, Harold N. Kvisle, certify that: 1. I have reviewed this quarterly report on Form 6-K of TransCanada Corporation; 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 registrant as of, and for, the periods presented in this report; 4. The registrant'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 registrant 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 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; (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 (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 (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and 5. The registrant's other certifying officer(s) 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): (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 (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. /s/ Harold N. Kvisle ------------------------------------- Dated July 25, 2003 Harold N. Kvisle President and Chief Executive Officer

EXHIBIT 8 CERTIFICATE PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT I, Russell K. Girling, certify that: 1. I have reviewed this quarterly report on Form 6-K of TransCanada Corporation; 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 registrant as of, and for, the periods presented in this report; 4. The registrant'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 registrant 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 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; (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 (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 (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and 5. The registrant's other certifying officer(s) 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): (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 (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. /s/ Russell K. Girling ------------------------------------- Dated July 25, 2003 Russell K. Girling Executive Vice-President, Corporate Development and Chief Financial Officer