What CPTPP is and how it works

The text the United States left

The Trans-Pacific Partnership was done at Auckland on 4 February 2016 and signed there by twelve governments. Its entry into force clause asked for ratification by at least six signatories together accounting for 85% of the combined gross domestic product of the original signatories, on figures for 2013, which made entry into force arithmetically impossible without the United States. The United States withdrew from the agreement on 23 January 2017, before it had entered into force for anyone.

The remaining signatories kept the text and rebuilt the instrument around it. They signed the result at Santiago on 8 March 2018 and it entered into force on 30 December 2018.

A short agreement carrying a long one

The Comprehensive and Progressive Agreement runs to seven articles and an annex. Article 1 incorporates the provisions of the Trans-Pacific Partnership by reference, mutatis mutandis, except for a handful of its final provisions. Everything a trader deals with, the tariff schedules, the rules of origin, the chapters on services, procurement and investment, is therefore the 2016 text, read through a 2018 wrapper.

Article 2 suspends the provisions listed in the Annex, and the suspension holds until the parties agree to end it. Twenty-two items are named there, most of them on intellectual property: patent term adjustment, data protection for biologics, the extension of copyright terms, technological protection measures. They were the provisions the United States had pressed for, and they were parked rather than deleted, which leaves them available if the original text ever comes back into play. Article 6 says as much in its own words: the parties review the operation of the agreement if the entry into force of the Trans-Pacific Partnership becomes imminent, or if it becomes clear that it will not enter into force at all.

Article 3 lowered the bar the 2016 text could not clear. The agreement enters into force 60 days after at least six signatories, or at least half of them, notify the depositary that their legal procedures are complete. Article 4 lets a party withdraw on six months' written notice to the same address. Article 7 makes the English, Spanish and French texts equally authentic and gives the English text the last word where they diverge.

The dates the depositary counted

New Zealand is the depositary, which is why the record of who is bound and from when is kept in Wellington and why every ratification is dated from the notification that arrives there. Australia, Canada, Japan, Mexico, New Zealand and Singapore notified during 2018, and the agreement entered into force for the six of them on 30 December 2018. Vietnam followed on 14 January 2019, Peru on 19 September 2021, Malaysia on 29 November 2022, Chile on 21 February 2023 and Brunei on 12 July 2023. For four and a half years the agreement was in force between some of its signatories and not others, and a signature on 8 March 2018 gave no trader anything until the notification followed it.

What the agreement is not

It is a free trade area and stops there. Each party keeps its own tariff on goods from outside, so nothing here is a customs union, and there is no common currency, no free movement of people and no shared budget. The standing institution is a Commission of ministers that meets once a year or so and decides by consensus, most recently in Melbourne on 21 November 2025 and by video on 26 June 2026.

Because every party keeps its own external tariff, a good crossing between them has to establish that it came from inside, and the rules of origin let materials from any party count towards that proof in any other. That accumulation is the mechanism that makes a dozen separate tariff schedules work as one area.

The agreement sets no condition on how a party governs itself. The records here file Brunei as an absolute monarchy and Vietnam as a one-party state, beside constitutional monarchies, federations and republics, and the text asks nothing of any of them on that point.

The Pacific, and the party with no coast on it

Every party except the United Kingdom is a member of APEC, the forum that has taken no new member since November 1998. The trade agreement had no such closed door: Article 5 says that any State or separate customs territory may accede, on terms and conditions agreed between the parties, and it names no ocean.

The memberships overlap in every direction. Four of the parties are in ASEAN, seven are also in the Regional Comprehensive Economic Partnership, two are in the USMCA, and all of them are in the World Trade Organization. A good moving between two of these countries may be eligible under more than one agreement, and the exporter chooses which to claim under.

Who may accede, and who has asked

The parties set out the terms at Auckland on 16 July 2023, in three conditions since referred to as the Auckland Principles: a candidate has to be able to meet the standards written into the agreement, to show a record of keeping the trade commitments it has already made, and to command the consensus of the parties.

The United Kingdom applied on 1 February 2021, the Commission established an accession working group on 2 June 2021, and the protocol was signed at Auckland on 16 July 2023. It entered into force on 15 December 2024 for the United Kingdom and the parties that had ratified it by then. The rest arrived one at a time: Australia on 24 December 2024, Mexico on 22 June 2026 and Canada on 1 September 2026.

Requests to begin the process are lodged with the depositary and several are open. China lodged one on 16 September 2021 and the Separate Customs Territory of Taiwan, Penghu, Kinmen and Matsu on 22 September 2021, in the words Article 5 makes room for. Ecuador followed on 29 December 2021, Costa Rica on 11 August 2022, Uruguay on 1 December 2022, Ukraine in 2023, Indonesia in September 2024 and Cambodia in December 2025.

Two have moved. Costa Rica was invited to begin at the Vancouver meeting on 28 November 2024, and its working group concluded on 6 May 2026, which leaves a protocol to sign and ratifications to gather before anything changes. Uruguay's request was accepted at Melbourne on 21 November 2025. The catalogue counts parties and not candidates, and it takes no position on which of the open requests should succeed.