Emissions trading system for aircraft operators

Since the Agreement between Switzerland and the EU on the linking of the emissions trading systems (ETS) came into force in 2020, flights within Switzerland as well as flights from Switzerland to the European Economic Area (EEA) and the United Kingdom (UK) have also been subject to the Swiss ETS. Aircraft operators must surrender emission allowances in the amount of their CO2 emissions. Aviation has been included in the EU’s ETS since 2012.

A maximum amount of newly available emission allowances in the emissions trading system ('cap') is determined annually based on aircraft operators' transport performance (measured in tonne-kilometres) in 2018. This maximum has been reduced by 2.2% each year since 2021 (linear reduction factor).

Each aircraft operator is allocated emissions allowances free of charge on the basis of a benchmark and that operator's transport performance in 2018. Fifteen percent of the cap is auctioned off and a set volume of emission allowances are retained as a special reserve for new or fast-growing operators. Emission allowances are freely tradable ('trade') and can be surrendered to the competent authority to cover the CO2 emissions caused, or sold to other ETS participants.

Participation in the Swiss ETS

Aircraft operators that carry out domestic flights in Switzerland or flights from Switzerland to the EEA or the UK are obliged to participate. Flights from the EEA to Switzerland are covered by the EU ETS, and flights from the UK to Switzerland are covered by the UK ETS (currently excludes flights from Northern Ireland). In line with arrangements in the EU, exemptions for special flights (e.g. military, rescue or research flights) and thresholds apply in the Swiss ETS. The thresholds are 10,000 t of CO2 per year or 243 flights in each of three consecutive four-month periods for commercial aircraft operators and 1,000 t of CO2 per year for non-commercial aircraft operators. If the aircraft operator has obligations under the EU ETS, these thresholds do not apply.

Free-of-charge allocation

For every aircraft operator, the FOEN calculates the annual quantity of emission allowances allocated free of charge based on that operator's transport performance in 2018, taking into account the linear reduction factor. The same benchmark and reduction factor apply as in the EU.

If an aircraft operator does not carry out any ETS-relevant flights in a particular year and thus is not required to surrender any emission allowances, it must return the emission allowances that were allocated to it free of charge for the year in question.


The FOEN regularly auctions off emission allowances via the Swiss Emissions Trading Registry (EHR). Those entitled to take part in these auctions include aircraft operators participating in the Swiss and EU ETSs and other companies from the EEA admitted to bid in auctions in the EU. Anyone wishing to take part in a Swiss EHR auction must have an account with the Swiss EHR. Detailed information about the auctions can be found in the fact sheet on auctions and the General Auction Terms and Conditions, available on the following website:

The dates, auction volumes, maximum and minimum bid quantities of the next auction and the results of the auctions already carried out are published in the EHR:

Reporting and obligation to surrender emission allowances

By 31 March each year, aircraft operators must report on their CO2 emissions for the previous year to the competent authority in the administering state (see 'One-stop shop'). They then have until 30 April to surrender sufficient emission allowances to cover these CO2 emissions. This is done in the emissions trading registry of the competent authority. Aircraft operators administered by Switzerland surrender their allowances/certificates in the Swiss EHR, while operators administered by a foreign authority do so in the Union Registry.

One-stop shop

In line with the 'one-stop shop' philosophy, aircraft operators who have obligations under both the Swiss and EU ETSs are only administered by one state. The competent authority in that state is responsible for all tasks related to the administration of the operator under both ETSs. This includes taking receipt of the annual emission reports, determining whether the operator has met its commitments and enforcing the operator's obligations.

Aircraft operators administered by Switzerland

The list of aircraft operators administered by Switzerland can be found at the bottom of the page under ‘Legislation’.

Swiss cap for aviation

The total quantity of emission allowances for aircraft is reduced each year by the linear reduction factor of 2.2%. As a result of the UK leaving the EEA, flights to the UK were not subject to the Swiss ETS in 2021 and 2022. The aviation cap for these years has been adjusted accordingly.

Quantity of Swiss emission allowances in the ETS for aircraft operators

Table A: Total quantity of emission allowances for aircraft ('aviation cap') as well as the quantities available for allocation free of charge, for auctions and for the special reserve.

  Aviation cap (total quantity)

for allocation
free of charge (partial quantity)
for auctions (partial quantity)
for the special reserve (partial quantity)
2020  1'310'035  1'074'229  196'505   0 
2021 1'072'636 879'562 160'895 32'179











Table B: CO2 emissions, aircraft operators subject to the ETS, actual emission allowances allocated free of charge in the Swiss ETS (as of: 02.02.2023).


CO2 emissions

Number of aircraft operators subject to the ETS

Emission allowances actually allocated free of charge









2022 1'084'023 173 855'043

Further information

Last modification 10.08.2023

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