Company: TCPA
Filing Date: 2025-10-06
Form Type: SUPPL
Source: 0001193125-25-231083
Chunk: 3

Company: TRANSCANADA PIPELINES LTD
Filing Date: 2025-10-06
Form: SUPPL
Chunk 3
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us supplement. Should the Underwriters exercise this option in full, upon the exercise of the option, the total initial public offering price, underwriting commission (assuming that no Notes are sold to institutions) and proceeds to the Corporation before expenses will be U.S.$ , U.S.$ and U.S.$ , respectively. The Notes are a new issue of securities with no established trading market. Wewill apply to list the Notes on the New York Stock Exchange (the “ NYSE”). If approved for listing, trading on the NYSE is expected to commence within 30 days after the Notes are first issued. The Underwriters, as principals, conditionally offer the Notes in the U.S., subject to prior sale, if, as and when issued by us and accepted by the Underwriters in accordance with the conditions contained in the Underwriting Agreement referred to under “ Underwriting” in this prospectus supplement, and subject to the approval of certain legal matters on our behalf by our Canadian legal counsel, Blake, Cassels & Graydon LLP, and by our U.S. legal counsel, White & Case LLP, and on behalf of the Underwriters by their U.S. legal counsel, Paul, Weiss, Rifkind, Wharton & Garrison LLP. The representatives of the Underwriters have advised us that the Underwriters propose to offer the Notes to the public initially at the public offering price specified above. After the Underwriters have made a reasonable effort to sell all of the Notes offered by this prospectus supplement at the price specified above, the offering price of the Notes may be decreased and may be further changed from time to time to an amount not greater than the price specified above. Any such reduction will not affect the proceeds we receive pursuant to the offering. In connection with the offering, the Underwriters may over-allot or effect transactions which stabilize, maintain or otherwise affect the market price of the Notes. As a result of such transactions, the price of the Notes may be higher than the price that might otherwise prevail. Such transactions, if commenced, may be discontinued at any time. See “ Underwriting ” in this prospectus supplement. We expect to deliver the Notes to investors through the book-entrydelivery system of The Depository Trust Company and its direct and indirect participants, including Euroclear Bank SA/NV and Clearstream Banking, S.A, against payment in New York, New York on or about October , 2025. Joint Book-RunningManagers

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