It depends on where your flights operate:

• EU ETS applies to flights within the European Economic Area (EEA), and to some routes between the EEA and partner countries.

• CORSIA applies to international flights between countries that participate in the ICAO CORSIA scheme.

Some airlines may need to comply with both, depending on their routes.

From 2027 aircraft operators will no longer receive any free allocations under the EU ETS.

You must buy CORSIA credits if your airline operates international flights between countries that are participating in the scheme for that year and your emissions exceed your baseline level.

Your emissions exceed baseline level if your annual CO₂ emissions from those covered flights exceed 10,000 tonnes, and those emissions are above the phase’s baseline, set at 2019 levels for the pilot phase (2021–2023) and at 85% of 2019 levels from the first phase (2024–2026) onward.

Participation by States is voluntary during the pilot and first phases, so your obligation depends on whether both the departure and arrival States have opted in for that year; in the second phase (2027–2035), participation is based on ICAO criteria plus any additional voluntary participants.

Your administering authority will confirm your coverage and the volume of credits you must surrender.

You can buy CORSIA credits from approved CORSIA carbon credit projects, Grey Epoch can help you source credits that meet both compliance and sustainability objectives.

Yes, airlines must use an approved CORSIA Emissions Unit Account  to hold and track CORSIA credits.

Credits are issued by approved providers, deposited into the account, and then surrendered to offset emissions above the 2019 baseline.

The account ensures proper verification, prevents double-counting, and facilitates compliance reporting to the International Civil Aviation Organization (ICAO).

Yes, CORSIA credits have a validity period. Only credits issued for eligible years under the scheme can be used for compliance, so airlines must ensure they use credits within the allowed timeframe to offset their emissions.

There are no confirmed plans, but alignment or integration is possible in the future.

By using forward contracts to secure prices in advance and timing purchases to benefit from favourable market conditions.

With tailored solutions for aircraft operators, Grey Epoch can support your business needs.

During the ETS review, the EU will assess if CORSIA efforts are in line with the Paris Agreement. If it’s determined CORSIA isn’t sufficiently strong, the EU might consider ending the “stop-the-clock mechanism” and start bringing departing extra-EU flights into scope.

Currently, only flights both departing and arriving from EEA countries are in scope (with some inclusions for Switzerland and the UK).

Annual Monitoring & Reporting Tasks

1 January

Start monitoring your international flight emissions for the current scheme year

Follow your approved Monitoring Plan

30 April

Submit verified annual emissions report for the previous year (via METS or state’s reporting system)

Report must be verified by an accredited verifier before submission

30 June

Submit improvement report (if applicable)

Required if the verification process identified areas for improvement

July

Begin the process of appointing your verifier for the current scheme year

Ensures timely verification the following year

31 December

Notify regulator of any non-significant changes to your monitoring plan

Applies to updates that don’t fundamentally change monitoring methods

31 December

Complete your emissions monitoring for the current year

End of the scheme year

Offsetting & Compliance Tasks

30 November

Regulator notifies you of your offsetting obligation for the previous scheme year

Based on verified emissions above baseline

30 November (every 3 years, starting 2024)

Regulator notifies you of your final offsetting obligation for the previous 3-year compliance period

Aggregated for 3-year phases (e.g., 2024–2026 → notification by 30 Nov 2027)

31 January (every 3 years, starting 2025)

Surrender eligible emissions units (credits) to offset the required emissions

Deadline for credit cancellation in line with regulator’s notification

7 February (every 3 years, starting 2025)

Request that the eligible emissions units registry publishes your cancellation information

Ensures transparency per CORSIA requirements

30 April (every 3 years, starting 2025)

Submit your verified emissions unit cancellation report for the previous compliance period

For the EU ETS, you must complete the following key tasks every year:

• 1 January: Start of the monitoring year.

• 31 March: Submit verified emissions report for the previous year.

• 30 September: Surrender the required allowances for the previous year.