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This page is a historical reference, not an open grant call.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. The UNFCCC Article 6 capacity-building work programme provides information, training, regional workshops, webinars, online courses, and technical assistance intended to help Parties and stakeholders understand Article 6 implementation. The programme addresses institutional arrangements, technical knowledge, baselines, monitoring, reporting, and participation in the mechanisms. Regional Collaboration Centres are identified as channels for Article 6 capacity building and technical support.

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. If the host Party approved the transition, its Article 6.4 DNA had to submit the approval to the Supervisory Body. 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. The host Party then had to provide its approval to the secretariat by 30 June 2026. This host-Party deadline applied after the participant submission deadlines; it was not a new opportunity for a project participant to file a late transition request.

The next documentation step depended on the methodology. If the activity continued to apply its current CDM methodology, the project participants had to submit an addendum to the registered PDD, or the relevant PoA-DD and CPA-DDs, showing compliance with the transition requirements by 31 December 2026. If the activity switched to an Article 6.4 methodology, it needed a revised PDD or revised PoA-DD and CPA-DDs plus a validation report from a designated operational entity. That submission was due within one year of publication of the host Party approval or within one year after the applicable methodology became available, whichever was later.

The secretariat then collected the transition fee, carried out a completeness check, and carried out a substantive check. The official FAQ notes that activities hosted in non-least-developed-country small-island-developing-state locations are waived from the transition fee under the stated process. The request could then be considered for review by the Supervisory Body, which could approve or reject it. If approved, the activity was deregistered from the CDM. The transition did not automatically move every CER into the Article 6.4 mechanism registry; separate registry rules and requests applied to eligible units.

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

Do not treat the 2025-12-31 value in this page as a live deadline. It is retained because it was the real final request deadline for the A/R category and because the site needs a concrete historical date rather than an invented future date. Non-A/R requests had an earlier final deadline of 31 December 2023. The official FAQ says that a request submitted after the applicable deadline cannot initiate the transition of a registered activity or finalize a provisional registration request.

Existing participants with a request already submitted should use the official FAQ, the transition procedure, the transition standard, and any direct UNFCCC notification associated with their case. They should check host-Party approval status, additional-documentation requirements, methodology instructions, and the applicable registry rules. The FAQ also distinguishes provisional requests for issuance: those requests have different timing treatment, but the underlying CDM activity must first transition successfully and the request still has to be submitted through the applicable process.

Parties and stakeholders preparing for other Article 6 work can use the UNFCCC Article 6 capacity-building programme and Regional Collaboration Centre resources for current guidance. Those resources are the appropriate place to look for training and technical support. This archived page should not be used as evidence of a current grant, a current open call, a guaranteed support package, or a new 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?

Not under the closed deadlines described by the official FAQ. The general deadline was 31 December 2023, and the A/R deadline was 31 December 2025. The FAQ expressly says that missing the applicable deadline makes transition impossible for the covered registered activity or provisional registration request.

Does host-country approval replace the participant deadline?

No. The participant had to submit the transition request first. The host Party’s separate approval deadline was 30 June 2026. A host Party approval deadline does 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 contact details and links on the official UNFCCC Article 6.4 transition FAQ, including the transition procedure and the current Article 6 capacity-building resources. A direct notification or case-specific instruction from the UNFCCC secretariat takes priority over this archive page.