Unit types
There are different types of units in emissions trading and in the Union Registry. Common to all types of units is that they correspond to one tonne of carbon dioxide equivalents. Certain unit types can only be held on accounts in the EU ETS while others may only be held on accounts in a registry under the Kyoto Protocol. Some unit types can be kept in both registries.
Below is a table describing which units can be held in each registry:
Unit type
* Can be held until 1 July 2023.
Unit types in the EU ETS
European Union Allowance (EUA)
European allowance that can only be held in accounts in the EU Emissions Trading Scheme. The unit type allocated to operators, surrendered during compliance and auctioned. During the fourth phase, the unit may be used for compliance by both operators and aircraft operators.
EUAA Aviation Allowance (EUAA)
European allowance that can only be held on accounts in the EU ETS. The unit type allocated to aircraft operators, surrendered during compliance and auctioned. During the fourth phase, the unit may be used for compliance by both operators and aircraft operators.
Swiss General Unit Allowance (CHU)
Allowance allocated to operators in the Swiss emissions trading system. The unit can be used for compliance in the EU ETS by operators and aircraft operators.
Swiss General Unit Allowance (CHUA)
Allowance allocated to aircraft operators in the Swiss emissions trading system. The unit can be used for compliance in the EU ETS by operators and aircraft operators.
Certified Emission Reduction (CER)
International credit from CDM projects. Operators may exchange the unit type to an allowance if such an exchange right exists, see the section on the exchange of international credits.
The Commission Delegated Regulation (EU) 2019/1122 Commission abolishes the use of international credits within the EU ETS in the fourth phase and therefore no international credits can be held in EU accounts.
After 30 April 2021, incoming transactions to an EU ETS account containing these units will not be allowed. After this date, the units can only be cancelled / removed or transferred to an account outside the EU ETS.
International credits can be held in EU accounts until 1 July 2023. Account holders who have international credits in their EU account after 1 July 2023 will be contacted and asked to remove these units. If the units are not removed, the Swedish Energy Agency will within 40 days remove the units from the respective EU account.
The EU ETS does not allow CERs from certain projects. It is the buyer’s responsibility to investigate whether the unit can be transferred to an account in the emissions trading system.
ERU (Emission Reduction Unit)
The Commission Delegated Regulation (EU) 2019/1122 Commission abolishes the use of international credits within the EU ETS in the fourth phase and therefore no international credits can be held in EU accounts.
After 30 April 2021, incoming transactions to an EU ETS account containing these units will not be allowed. After this date, the units can only be cancelled / removed or transferred to an account outside the EU ETS.
International credits can be held in EU accounts until 1 July 2023. Account holders who have international credits in their EU account after 1 July 2023 will be contacted and asked to remove these units. If the units are not removed, the Swedish Energy Agency will within 40 days remove the units from the respective EU account.
The EU ETS does not allow CERs from certain projects. It is the buyer’s responsibility to investigate whether the unit can be transferred to an account in the emissions trading system.
AAU (Assigned amount unit)
The unit type assigned to the Kyoto Protocol, which has obligations to hand over units corresponding to their emissions, such as Sweden. Sweden allows private entities to keep the unit type on accounts in the Swedish registry under the Kyoto Protocol. However, this may not apply to all other countries’ Kyoto Registries.
lCER (Long Term Certified Emission Reduction)
International credit issued in Forest Planting Projects and Replanting Projects under CDM. The unit type has a limited life and is only valid during the Kyoto Protocol commitment period in which it was issued.
tCER (Temporary Certified Emission Reduction)
International credit issued in Forest Plant Projects and Replanting Projects under CDM. The unit type has a limited service life and expires at the end of the commitment period under the Kyoto Protocol following that in which it was issued.
RMU (Removal Unit)
Credit issued for greenhouse gas uptake in the LULUCF sector.
