Tradable units
Important information regarding the validity of EU Allowances (EUA) and Aviation Allowances (aEUA) of phase 3 and phase 4 in the EU ETS
Phase 3 of the EU emissions trading system (EU ETS) ended on 31 December 2020, phase 4 (period 2021 – 2030) started on 1 January 2021. General Allowances (EUAs) and Aviation Allowances (aEUAs) of phase 4 allocated from January 2021 onwards are marked as units of phase 4 and may only be used to comply with surrender obligations for emissions from phase 4 and later phases.
Phase 3 allowances are still valid indefinitely and can therefore also be used for trading from 2021 onwards, and to comply with surrender obligations for phase 4 emissions. It is possible to see in the Union Registry whether allowances were created in phase 3 or in phase 4.
EU allowances and Kyoto units
A list of units that may currently be held by a natural or legal person on an account in the Union Registry is provided below. Each of the allowance types listed here is valid subject to the restrictions described above and below, and permits the emission of one ton of CO2 (carbon dioxide) or CO2 equivalent during a specified period:
- EU Allowances (EUAs): allowances used for emissions trading within Europe (European emissions trading system). EUAs can be used by operators of installations and aircraft operators to comply with their surrender obligations.
- Aviation allowances (aEUAs): allowances for aircraft operators for emission trading within Europe (European emissions trading system). As of 2025, aircraft operators will be allocated EUAs; existing aEUAs will remain valid.
- Swiss general allowances (CHUs): these allowances are generated in the emissions trading registry of Switzerland; they can be used in the EU emissions trading system by operators of installations and aircraft operators to comply with their surrender obligations.
- Swiss aviation allowances (aCHUs/CHUAs): these allowances are generated in the emissions trading registry of Switzerland; they can be used in the EU emissions trading system by operators of installations and aircraft operators to comply with their surrender obligations.
The European Energy Exchange (EEX) was appointed by the European Commission as common auction platform for the auctioning of allowances. All information on the auctions, including the auction calendar, is published on the EEX website, which can be visited at the following link: