SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16 of

the Securities Exchange Act of 1934

For the month of ~~May~~July 2026

Commission File No. 1-8887

TransCanada PipeLines Limited

(Translation of Registrants’ Names 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 o Form 40-F þ

Exhibit 99.1 to this report, furnished on Form 6-K, shall be incorporated by reference into the following Registration Statements under the Securities Act of 1933, as amended, of the registrant: Form F-10 (File No. 333-283633).

EXHIBIT INDEX

99.1 Schedule of earnings coverage calculations at ~~March~~June 3130, 2026.

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.

Date: May 1, 2026	TRANSCANADA PIPELINES LIMITED
Date: July 30, 2026	TRANSCANADA PIPELINES LIMITED
	By:	/s/ Sean P. O'Donnell
		Sean P. O'Donnell
		Executive Vice-President, Strategy and Corporate Development and Chief Financial Officer
	By:	/s/ Yvonne Frame-Zawalykut
		Yvonne Frame-Zawalykut
		Vice-President and Corporate Controller
		Vice-President and Controller

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