Company: TCPA
Filing Date: 2025-02-14
Form Type: 6-K
Source: 0000099070-25-000002
Chunk: 0

Company: TRANSCANADA PIPELINES LTD
Filing Date: 2025-02-14
Form: 6-K
Chunk 0
---
### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

#### FORM 6-K
<div align='center'>Report of Foreign Private Issuer

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

the Securities Exchange Act of 1934

For the month of February 2025

Commission File No. 1-8887</div>

#### TransCanada PipeLines Limited
<div align='center'>(Translation of Registrants’ Names into English)

450 - 1 Street S.W., Calgary, Alberta, T2P 5H1, Canada

(Address of Principal Executive Offices)</div>

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

<div align='center'>Form 20-F o Form 40-F þ</div>

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 Nos. 333-267323 and 333-283633).

### EXHIBIT INDEX

### 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: February 14, 2025 |     | 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                                                  |