CDM Registry

Institutional background

The Conference of the Parties serving as the meeting of the Parties to the Kyoto Protocol on its first session, held at Montreal from 28 November to 10 December 2005, established that the CDM Executive Board shall develop and maintain the CDM registry according to the requirements set out in Appendix D to the report (FCCC/KP/CMP/2005/8/Add.1).

These requirements specify that the CDM registry is to be in the form of a standardized electronic database that ensures the accurate accounting of the issuance, holding and acquisition of CERs. In order to do so, Appendix D to Decision 3/CMP.1 provides guidance on the different account types to be available in the CDM registry, provisions for unique serial numbers, conditions for the forwarding of CERs and publicly available information about the operation of the CDM registry.

This document also establishes that

The Executive Board shall establish and maintain a CDM registry to ensure the accurate accounting of the issuance, holding, transfer and acquisition of CERs by Parties not included in Annex I.

The Executive Board shall identify a registry administrator to maintain the registry under its authority.

(3/CMP.1, Annex, Appendix D, paragraph 1). The Executive Board of the Clean Development Mechanism designated the UNFCCC Secretariat as the CDM registry administrator at its thirteenth meeting.

The Annual report (2003–2004) of the Executive Board of the clean development mechanism to the Conference of the Parties also states that the Board agreed that the secretariat is to be the CDM registry administrator with responsibility, under the authority of the Board, for implementing and operating the CDM registry (CP/2004/2/ paragraph 59).

Publicly available information can be found on the issuance of CERs section.

Information about the amount of CERs allocated to the Adaptation Fund account can be found here

The Executive Board provided further guidance for the work of the CDM registry at its subsequent meetings. The reports of each meeting containing the corresponding decisions can be found on the EB section .

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Online platform for voluntary cancellation of CERs:

The online platform was launched in September 2015 to allow members of the public to offset their carbon footprint in a simple and transparent way.

The platform is a web based application that allows project participants to offer the voluntary cancellation of their CERs held in the CDM registry at a price they determine. Members of the public can filter available CERs by project type, country or other criteria to ensure their action supports GHG mitigation activities which are in line with organizational goals or personal preferences. Paid CERs are cancelled in the CDM registry through a paperless process. For each purchase of CER cancellation, the CDM registry administrator issues an attestation of cancellation.

Approximately 11.8 million CERs have been cancelled on the platform until December 2023 by organizations and individuals that want to neutralize their carbon footprint.

The secretariat has prepared a brochure for interested project participants. The brochure explains the benefits of the platform, how it works, eligibility of projects and how to open an account.  

The platform is available at the following link:

The page listing the details of  voluntary cancellations in the CDM Registry through the online platform can be found in the following link:

Permanent holding account representatives or project participants  who hold CERs in the pending account and are  interested in offering CERs for voluntary cancellation on the platform,  can contact us at:

CDM Registry News - Operational

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  • 27 March 2024 - Non-responsive DNAs

Several project participants have brought to the attention of the secretariat that some DNAs are non-responsive. To guarantee smooth operation of the CDM, it is crucial that DNAs are contactable and responsive.

After the secretariat brough this matter to the Executive Board which then referred the matter to the Conference of the Parties, the Executive Board has decided at its last meeting in March 2024 to bring this matter to the attention of the UNFCCC National Focal points.

At its last meeting in March 2024 the Executive Board has decided the following: “The Executive Boardrequested the secretariat to initiate written communication with the UNFCCC National Focal Points of the Parties to the Kyoto Protocol of non-responsive DNAs as identified by project participants in order to confirm whether the DNA is no longer operational.

Furthermore, the Board requested the secretariat to reach out to the Heads of delegations of the  Parties to the Kyoto Protocol that have not responded to the above communication prior to the next meeting and report back to the Board”.

More information can be found at the meeting report of the EB in the following link ( Agenda item 2.2 Strategic planning and direction, paragraphs 9 and 10) CDM EB: 121st meeting report

  • 8 December 2020 - Accounts in the UK Kyoto National Registry as of 1 January 2021

    • As of 1 January 2021, account holders of accounts in the UK Kyoto National Registry will no longer have access to these accounts, and transfers of CERs to the Kyoto National Registry of the UK will no longer be possible. The UK government is procuring a new system to enable account holders to hold and trade Certified Emission Reductions and Emission Reduction Units, which they expect to be operational in Spring 2021.

CDM Registry News - Regulatory

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  • 29 June 2023 - Questions and answers on emissions trading under the Kyoto Protocol in relation to the end of the second commitment period

    • The additional period for fulfilling commitments (true-up period) of the second commitment period (CP2; 2013-2020)  of the Kyoto Protocol started on 1 June 2023 and will end on 9 September 2023 at 23:59:59. The Conference of the Parties (COP) serving as the meeting of the Parties to the Kyoto Protocol will consider, at its 18th session (CMP18), the functioning and operation of the processes and institutions of the clean development mechanism in the future.
    • For more information, kindly refer to the dedicated website for the True Up Period here which contains an FAQ document that is being updated on a regular basis.
  • 23 September 2020 - Status of CP1 CERs after true-up period

    • CP1 CERs that are held in the CDM registry are not subject to the automatic cancellation procedure that applies to CERs that are held in Annex I Party registries. They may continue to be held in the CDM registry, transferred within the CDM registry, and voluntarily cancelled in the CDM registry after the end of the true-up period.There are also no restrictions with regard to the continuation of issuance of CP1 CERs in the CDM registry. It is possible that the CDM Executive Board may set a deadline for receiving requests for issuance for CERs corresponding to emission reductions or removals achieved on or before 31 December 2012 but it is expected that any such deadline would have substantial lead time.For more information kindly refer to our FAQ Post 2012 issues section.
  • 1 July 2020 - Removal of the limit on the number of instalments for the partial payment of the Share of Proceeds.

    • At its 106th meeting, the CDM Executive Board decided to remoge the limit on the number of installments of share of proceeds for CERs in the pending account of the CDM Registry. Further information on partial payment of the share of proceeds is available here.
  • 13 December 2017 - Share of proceeds for administration - amendments to the CDM project/PoA cycle procedures approved at EB96.

    • At its  ninety-sixth meeting (EB 96), the Executive Board of the clean development mechanism approved changes to the CDM project cycle procedures with respect to the SOP for administration. The changes include:

  • 08 July 2015 - CP1 CERs not accepted by the Swiss National Registry

    • Following the implementation of national legislation in Switzerland the Swiss National Registry has prohibited incoming international transactions containing units from commitment period 2008-2012 (CP1) since 30 April 2015; in this connection any requested transfers of CP1 units designated to the Swiss national registry will be rejected.  Please note that this deadline does not apply to CP2 credits.  For further information please contact the Swiss national registry at the following email address:
  • 10 July 2013 - Commitment period 2 (CP2) deployment

    • Commitment Period 2 (CP2) capabilities related to requests for issuance and forwarding of units will be available to stakeholders from Friday 12 July 2013. The new functionality includes the option to request issuance/forwarding of units from Commitment Period 1 (CP1) and Commitment Period 2 (CP2) or a combination of units from both commitment periods.
  • 20 June 2013 - Commitment period 2 (CP2) capabilities to be deployed

    • Commitment Period 2 (CP2) capabilities related to requests for issuance and forwarding are expected to be deployed for external users in the second week of July 2013.
  • 16 October 2012 - Introduction of voluntary cancellation of CERs in the CDM registry: launch on 15 November 2012

    • Further to its adoption by the Executive Board at its 69th meeting, the CDM Registry is pleased to announce the introduction of a Voluntary Cancellation Accountfor the purpose of cancelling CER/lCER/tCER units on a voluntary basis.
    • The voluntary cancellation mechanism will allow project participants who hold CERs/tCERs/lCERs in either a holding account or the pending account in the CDM Registry to cancel units on their own behalf or on behalf of third parties. Upon confirmation of a voluntary cancellation request the CDM Registry will issue an 'Attestation of Voluntary Cancellation' to the requestor of the cancellation transaction and publish the information on the CDM Registry web site.
    • Reports on transactions related to Voluntary Cancellations will be published on a bi-weekly basis on the 'Public Reports' section of the CDM Registry web page.
    • Voluntary cancellation transactions shall be requested following the normal procedures for forwarding from holding accounts and from the pending account of the CDM Registry. Detailed information on how to request voluntary cancellation will be published prior to the release date on the CDM Registry News - Operational page and on the How to/ Guidance section of the CDM Registry web page.
    • A web-based facility will be created on the CDM Registry web page to serve as a platform to facilitate interaction with potential providers of units for voluntary cancellation. The Voluntary Cancellation Service will provide a transparent and accessible forum for exchange of information. Further information on how to use the platform will also be published prior to the release date on the CDM Registry News - Operational page and on the How to/ Guidance section of the CDM Registry web page.
  • 20 June 2012 - Activation of the Union registry for EU Member States

    • The full activation of the EU Emissions Trading System single registry, including the migration of over 30,000 EU ETS accounts from national registries, is scheduled to take place on 20 June 2012. The transition timetable is as follows:
    • Starting on 14 May 2012 at 10:00 CEST, account holders will not be able to open or close accounts or to modify account and account representative details, neither in national registries nor in the single registry.
    • From 3 June 2012 at 10:00 CEST, the operation of national registries and the single registry will be suspended and account holders will not be able to access registry accounts - including allowances held in these accounts.
    • On 20 June 2012 at 12:00 CEST, the single registry will be fully activated. Users of existing national registries will be able to use the single registry as soon as they receive their new authentication credentials from their national administrator.


  • 24 Oct 08 — CDM registry starts live operations with EU registries

The CDM registry is pleased to announce that, as a result of the successful connection of EU registries and CITL to the ITL, our live operations with EU registries have officially started on Wednesday 22 October. As from that date the CDM registry has been able to forward CERs held in temporary holding accounts to their associated EU registries for all cases where the national registry ID was made available by account representatives and where the receiving national registry confirmed their readiness to receive them.

Entities responsible for instructing on forwarding of CERs from the Pending account of the CDM registry to acquiring holding accounts of project participants authorised by an EU country, as stated in the modalities of communication, are encouraged to check whether the corresponding EU national registry is available to receive CERs from the CDM registry and to ensure that the receiving account corresponds to an account within that national registry.

Account representatives of temporary holding accounts that are still expecting to receive CERs in the corresponding national registry are requested to ensure that the national registry account ID has been instructed through the CDM registry online interface (user name and password needed).

  • 16 Oct 08 — Successful connection of the CITL and EU national registries to the ITL

The UN Climate Change secretariat announced on Tuesday 14 October 2008 that it is on schedule to complete the live connection of the UNFCCC International Transaction Log (ITL) with the European Union (EU) Community Independent Transaction Log (CITL) and 26 European Union greenhouse gas emissions trading system (EU ETS) registries. As a result of this, the CDM registry and other Non-EU registries have been switched back to "Operating" mode as from today Thursday 16 October. The CDM registry is therefore now fully operational and able to resume forwarding of CERs as usual.

Please note, however, that the forwarding of CERs from Temporary Holding Accounts (THAs) to the associated EU registries will not take place until all the preparatory work has been completed in coordination with the receiving registries. The exact date when all these CERs will be sent to EU registries will be advised on this page in the next few days.

  • 01 Oct 08 — Connection of the CITL and EU registries to the ITL

The European Commission (EC), Member States and the secretariat of the United Nations Framework Convention on Climate Change (UNFCCC) are currently working on the last preparatory phases of setting up a live connection between the CITL, the UNFCCC International Transaction Log (ITL) and Member State registries. The final connection process between the ITL and CITL will start on 6 October at 8:00 am CEST and is expected to take at least 10 calendar days (see here).

Please note that, as a result of this process, the CDM registry will not be available for forwarding transactions during that time starting on October 7 2008. Although issuance of CERs will still be conducted as usual, ensuing forwarding requests will not be processed until the connection process is finalised.

Once this connection process has been successfully completed, the CDM registry intends to forward all CER units currently held in temporary holding accounts to the national registries they are associated with. All CERs contained in a temporary holding account will be forwarded to the receiving account in the national registry in a single transaction. Specific instructions in this regard are being provided to account representatives via email.

For further information about the announcement mentioned above, please refer to the following links: