Registry Functions

Registries record the holdings of Kyoto units, and any transactions involving them, through a structure of accounts. This is similar to the way that banks record balances and movements in money using accounts allocated to individuals or other entities.

Data Exchange Standards have been developed to coordinate the electronic messaging that occurs between registry systems when processing transactions. The types of Kyoto units and transactions enabled by these standards are summarized in the tables below. The International Transaction Log (ITL), the European Union Transaction Log (EUTL) and registries also process unit types and transactions defined under other emissions trading schemes, such as European Union (EU) allowances for the first phase of the EU trading scheme and other transaction sub-types defined under this scheme.

The data held by registries is reconciled on a daily basis with data in the ITL and EUTL. Procedures are in place for identifying and resolving any inconsistencies discovered.

Kyoto units
Unit	Unit name	Issuer	Description	Kyoto Protocol
AAU	Assigned Amount Units	National registry	Units representing the initial assigned amount of each Annex B Party.	Article 3.7
RMU	Removal Units	National registry	Units given for net removals from land use, land-use change and forestry activities.	Article 3.3, 3.4
ERU	Emission Reduction Units	National registry	Units converted from AAUs or RMUs on the basis of JI projects.	Article 6
CER	Certified Emissions Reductions	CDM registry	Credits given for emission reductions certified for a CDM project.	Article 12
tCER	Temporary CERs	CDM registry	Credits given for emission removals certified for an afforestation or reforestation CDM project (to be replaced upon expiry at end of the second commitment period).	Article 12
lCER	Long-term CERs	CDM registry	Credits given for emission removals certified for an A&R CDM project (to be replaced upon expiry at end of the project's crediting period or in event of storage reversal or non-submission of a certification report).	Article 12

Kyoto transaction types
Issuance	Initial creation of an AAU, RMU, CER, tCER or lCER.
Conversion	Transformation of an AAU or RMU into an ERU based on a JI project.
External transfer	External transfer of a unit from one registry to another registry.
Cancellation	Internal transfer of a unit to a cancellation account, in order that it may not be used for compliance with an emission target.
Replacement	Internal transfer of a unit to a replacement account, in order to replace tCERs or lCERs when required.
Retirement	Internal transfer of a unit to a retirement account, in order that it can be used by the Annex B Party for compliance with its emission target.
Carry-Over	Change of validity an AAU, ERU (only those converted from AAUs) or CER from one commitment period to the next.
Expiry date change	Change in the expiry date of a tCER or lCER.
Internal transfer between holding accounts	Internal transfer of a unit between holding accounts within the same registry (the ITL does not verify such transactions but forwards them to the CITL to allow their verification under the EU trading scheme).