CDM to Article 6.4 Transition Process: Closed Deadlines and UNFCCC Guidance

This page is a historical reference, not an open grant call. The official UNFCCC material does not describe a programme that awards USD $150,000–$500,000 to project developers. It describes the rules and support resources for moving eligible Clean Development Mechanism (CDM) activities into the Paris Agreement Crediting Mechanism (PACM), also called the Article 6.4 mechanism. No fixed cash award is advertised on the official source.

The transition-request window is closed. The latest deadline in the official process was 31 December 2025 for CDM afforestation and reforestation (A/R) project activities, programmes of activities (PoAs), and component project activities (CPAs) in those PoAs. For other CDM project activities and PoAs, the request deadline was 31 December 2023. The UNFCCC FAQ says that a transition request cannot be submitted after the applicable deadline. It does not announce a new application round.

Key details

What the official process covered

The CDM was created under the Kyoto Protocol. Article 6.4 is the centralized crediting mechanism established under the Paris Agreement. The UNFCCC transition rules were designed for certain existing CDM activities and provisional requests rather than for every carbon project. A successful transition was not automatic: the activity had to meet the eligibility conditions, the host Party had to approve it, the project participants had to provide the required documentation, and the Article 6.4 Supervisory Body had to approve the request.

The official FAQ identifies several categories that could be considered. They included registered CDM project activities, registered PoAs, CPAs included in registered PoAs, and certain requests that had been listed as provisional under temporary CDM measures. A project participant could not use the transition route simply because a project had once been discussed as a CDM project. The activity had to fall within the formal categories and satisfy the stated conditions.

One eligibility condition concerned timing. A registered activity’s crediting period or a PoA’s period generally needed to have been active on 1 January 2021. The FAQ gives a qualification for provisional requests for registration. It also explains that a project whose crediting period had expired before 1 January 2021 and that had not submitted a renewal request under the CDM by 31 December 2021 could no longer meet that condition. A PoA with an earlier expiry could have a different route through renewal, but that did not guarantee that a transition request could be filed by the relevant deadline.

The host Party also mattered. The activity type had to be among the types the host Party indicated it would approve under the Article 6.4 rules. The applied CDM methodology had to meet methodological requirements specified by that host Party. If it did not, the activity would need to replace it with an Article 6.4 methodology. The official FAQ further says that transitioning activities use the global-warming-potential values applicable to Article 6.4 activities, including the values from the IPCC Fifth Assessment Report or any later values agreed by the governing body.

What “support” means here

The old page treated support as a large technical-assistance package with a stated dollar value, a 12–24 month service period, buyer matchmaking, and possible co-financing. The UNFCCC source does not confirm those claims, so they should not be used to plan an application or budget. This entry should not be read as a grant listing.

The official support is institutional and technical. UNFCCC materials provide procedures, FAQs, online learning, practical explainers, webinars, and capacity-building for Parties and project participants working through Article 6 implementation. Regional Collaboration Centres support Parties as they establish national arrangements and prepare activities. In September 2026 the Secretariat and its Regional Collaboration Centres held a third CDM Transition Support Clinic. Its stated focus was activity-level completion of transition requirements, including the addendum to design documents and the Article 6.4 Sustainable Development (SD) Tool. The official event page also points to an online module on transitioning from CDM, explainers for the addendum and SD Tool, and practical transition guidance.

Those resources can help a country, DNA, or project participant understand the transition requirements, but they do not replace the formal submission process. They also do not guarantee approval, provide a stated project-development grant, or turn an ineligible CDM activity into an eligible Article 6.4 activity. A project participant still has to work through the official process and any requirements imposed by the host Party.

Eligibility in practical terms

The strongest candidate for the closed transition route was an existing CDM activity with a clear registration record, an active or qualifying crediting period, and a host Party willing to consider the activity under Article 6.4. The relevant party needed access to the project design document (PDD), PoA-DD and CPA-DD documents where applicable, monitoring information, the activity’s methodology history, and the records needed to show compliance with the transition standard.

The host Party was not a passive reference. After a transition request was published, the UNFCCC secretariat informed the host Party. The current UNFCCC transition page directs a host Party that has not yet met the PACM participation requirements to send completed form A6.4-FORM-GOV-001 to the Secretariat by email. Its Article 6.4 designated national authority (DNA) provides the transition approval by sending completed form A6.4-FORM-AC-003 to the same Secretariat contact. The official deadline for host Party approval was 30 June 2026, and that date has passed. A project participant therefore needed an identifiable host-country channel and enough technical information for the authority to assess the activity. For a multi-country PoA, the relevant host Parties had to be considered under the applicable rules.

New projects that were never registered or provisionally listed under the CDM were not the target of this transition process. They would need to examine the ordinary Article 6.4 activity cycle or another applicable carbon-market framework. Likewise, a project owner looking only for unrestricted cash support would not find that offer on the UNFCCC transition FAQ.

Official process and required work

The UNFCCC describes the transition as a sequence rather than a short funding application. The first step was a transition request from the project participants to the secretariat. Eligible non-A/R project activities and PoAs had to submit by 31 December 2023. Eligible A/R activities, A/R PoAs, and their CPAs had to submit by 31 December 2025. The FAQ says eligible participants were individually provided a link to the web portal and that the request information was entered through that interface.

After submission, the request went through a 28-day global stakeholder consultation. Host Parties had until 30 June 2026 to provide their approval to the Supervisory Body; that date has now passed. The UNFCCC’s current transition page says the participant deadline was not reopened. Project participants should check the published status of their own activity and use any direct Secretariat instructions for remaining steps.

The next documentation step depends on the methodology and the transition case. If an activity continues to apply its current CDM methodology, participants must submit an addendum to the registered PDD, or the relevant PoA-DD and CPA-DDs, by 31 December 2026. Current UNFCCC materials also identify the Article 6.4 Sustainable Development Tool and its environmental and social safeguards and sustainable development forms as part of the additional documentation. The Supervisory Body’s rules page says transitioning participants must use the SD Tool unless they had already submitted additional transition documentation before 9:00 Central European Time on 11 February 2025. If an activity switches to an Article 6.4 methodology, participants need revised design documents using the corresponding PACM forms and a validation report from a designated operational entity accredited in the relevant sectoral scope. The submission is due within one year of publication of the host Party approval or within one year after the applicable methodology becomes available, whichever is later.

After the additional documentation step, the Secretariat carries out a completeness check and substantive check; the Supervisory Body may review the request and then approve or reject it. Approval results in deregistration from the CDM. The official FAQ says activities hosted in non-least-developed-country small-island-developing-state locations are waived from the transition fee under the stated process. The transition does not automatically move every CER into the PACM registry; separate registry rules and requests apply to eligible units. The current transition page also directs authorized focal point entities to the Paris Agreement Crediting Mechanism Information System (MIS) for additional documentation when a host Party has approved a transition. The page says MIS currently supports only activities hosted by a single Party that continue using a CDM methodology; for multi-Party activities and cases using an Article 6.4 methodology, documentation should be sent to the Secretariat by email.

What applicants would have prepared

For a case that had been within the closed window, preparation would have started with the CDM registration or provisional-request record. The participant would have checked the crediting-period or PoA-period status, the activity type accepted by the host Party, the applied methodology, and the applicable Article 6.4 requirements. The project team would also have needed to identify whether it could keep the CDM methodology or had to move to an Article 6.4 methodology.

The formal file could include the transition request entered in the UNFCCC interface, the registered design documents, an addendum or revised design documents, monitoring and supporting evidence, and validation material when a methodology change required it. Host-Party approval was a separate responsibility. Stakeholder consultation was also part of the process, so a participant should have monitored the UNFCCC publication and responded to relevant comments through the designated process.

This is why the official guidance is more useful than a generic promise of technical assistance. It tells a project participant which decisions affect eligibility, which authority must act, which documents may be required, and which review stages follow submission. It does not promise that all legacy CDM projects will receive a new crediting period or that Article 6.4 approval will follow from CDM registration alone.

What to do now

The participant application window is closed, and the official UNFCCC pages publish no replacement round. Keep 2025-12-31 in the deadline field because it is the actual final request date for the A/R category. Non-A/R project activities and PoAs had an earlier final request date of 31 December 2023. The FAQ explicitly says a late request cannot start a transition for a registered activity or finalize a provisional registration request. Neither the later host-Party approval date nor the remaining documentation milestones let a participant file a new transition request.

An existing participant should first locate the activity in the UNFCCC list of transition requests that underwent global stakeholder consultation and review any case-specific message from the Secretariat. The host Party approval deadline was 30 June 2026. The current transition page identifies procedure A6.4-PROC-AC-001, version 07.0, as the controlling procedure, and directs host Party participation forms and DNA approval forms to the Secretariat at [email protected]. For a host Party-approved activity continuing its CDM methodology, the current UNFCCC page says the participant must submit an addendum to the project or programme design documents by 31 December 2026. Participants must also provide the Article 6.4 Sustainable Development Tool documentation unless their additional transition documentation was already submitted before 9:00 Central European Time on 11 February 2025. The page identifies the Paris Agreement Crediting Mechanism Information System (MIS) as the route currently available for this submission when the activity is hosted by one Party and retains a CDM methodology. Authorized focal point entities for scope (c) can register using their listed email. The system’s published limits matter: the official page directs multi-Party activities and those using an Article 6.4 methodology at transition to submit documentation by email to [email protected].

Where an activity replaces its CDM methodology, the current transition page calls for revised project or programme design documents on the corresponding PACM forms and validation by a designated operational entity accredited for the relevant sectoral scope. The deadline is within one year of the host Party approval publication or within one year after the applicable mechanism methodology becomes available, whichever is later. This is an existing-case document path, not a new application period. Participants should consult the official transition procedure and direct case instructions before submitting; this archive cannot determine an individual activity’s approval status or exact document due date.

The FAQ separately explains limited treatment of provisional issuance requests. A request to finalize a provisional issuance does not use the ordinary participant transition deadline, but its underlying CDM activity must first have transitioned successfully. Eligibility depends on the methodology used at transition, and the current procedure remains necessary. This exception does not reopen registration or transition requests for projects that missed the relevant deadline.

Parties and stakeholders preparing for other Article 6 work can use UNFCCC capacity-building and Regional Collaboration Centre resources for general guidance. Those resources are not a grant application route and do not replace the formal PACM procedures. Treat this listing as an archive for the closed transition request window and as orientation for locating official material about cases already in progress. It is not evidence of a current open call, a guaranteed support package, or a future deadline.

Frequently asked questions

Is this a grant worth up to $500,000?

No. The official UNFCCC transition FAQ does not advertise a fixed cash award or a technical-assistance package valued at $150,000–$500,000. The relevant support consists of official procedures, guidance, training, workshops, and capacity-building resources.

Can a project submit a new transition request now?

No. The general deadline was 31 December 2023, and the A/R deadline was 31 December 2025. The FAQ says missing the applicable date makes transition impossible for a covered registered activity or provisional registration request. The later documentation steps apply to eligible cases already submitted and approved; they do not create a fresh request window.

Does host-country approval replace the participant deadline?

No. Participants had to submit first. The host Party’s separate approval deadline was 30 June 2026, as extended by the decision referenced on the current UNFCCC transition page. It has passed, and it did not reopen the participant submission window.

Are all CERs automatically transferred after approval?

No. The UNFCCC registry guidance says that CERs do not automatically move to the Article 6.4 mechanism registry with a transitioned project. Eligible CER transfers follow separate registry procedures and conditions.

Where can a participant ask a current procedural question?

Use the current UNFCCC transition page, its linked FAQ and procedure, and any direct case-specific notice. The UNFCCC lists [email protected] for questions and for documentation routes that the page directs by email. A direct instruction from the Secretariat takes priority over this archive page.