UK ETS for aircraft and ships
Aircraft operators are UK Emissions Trading Scheme participants: they report verified emissions by 31 March and surrender allowances by 30 April, with free allocation gone from 2026. CORSIA runs alongside for international flights. And from 1 July 2026 the scheme reaches shipping — ships of 5,000 gross tonnage and above, whatever their flag.
Which flights are in the scheme
Domestic, UK–Gibraltar, and UK-departing flights to the EEA and Switzerland — not every international departure.
501 Aircraft operators are UK ETS participants under The Greenhouse Gas Emissions Trading Scheme Order 2020 (SI 2020/1265), covering UK domestic flights, flights between the UK and Gibraltar, and flights departing the UK to European Economic Area states and Switzerland.
Report by 31 March, surrender by 30 April
Two deadlines, a month apart, and two distinct obligations.
502 An aircraft operator must submit a verified annual emissions report by 31 March covering the previous scheme year, and surrender enough UK allowances to cover that year’s reportable emissions by the following 30 April. 503 Free allocation of allowances to aircraft operators has been phased out from 2026: the entitlement ran only for the 2021-to-2025 period, and from 2026 aircraft operators receive no free aviation allowances and must obtain allowances to meet their surrender obligation.
- FROM 2026Aviation free allocation ends
- 1 JUL 2026Maritime: domestic voyages & ports
- 1 JAN 2027Maritime: offshore vessels added
- 31 MAR (ANNUAL)Verified emissions report due
A separate ICAO-origin regime, not part of the ETS
International-flight offsetting runs in parallel, under its own 2021 Order.
504 CORSIA is an ICAO-origin offsetting scheme implemented in UK law by The Air Navigation (Carbon Offsetting and Reduction Scheme for International Aviation) Order 2021 (SI 2021/534), administered by the UK Regulator. 505 Under it, an aeroplane operator must monitor and record its fuel use from international flights using an eligible monitoring method, and submit annually verified emissions reports to the Regulator. That monitoring-and-reporting duty applies to covered operators regardless of the offset-surrender stage.
Ships of 5,000 gross tonnage and above
From 1 July 2026 the ETS reaches shipping — starting with domestic voyages, on a volume-based threshold.
506 From 1 July 2026 the UK ETS is extended to maritime by The Greenhouse Gas Emissions Trading Scheme (Amendment) (Extension to Maritime Activities) Order 2026 (SI 2026/392), covering ships of 5,000 gross tonnage and above regardless of flag state. Domestic maritime voyages and port activity are in scope from 1 July 2026, with offshore vessels added from 1 January 2027.
Gross tonnage, not tonnes of CO2
The 5,000 GT threshold is gross tonnage — a measure of a ship's internal volume — not an emissions figure.
The initial 1 July 2026 scope is domestic voyages and port activity for ships at or above that size; it does not apply to all ships or to international voyages from day one.
Three gases, and a 42-day monitoring-plan window
The maritime rules differ from aviation's: more gases, and an entry deadline tied to first activity.
507A maritime operator must apply for an emissions monitoring plan within 42 days of first maritime activity, and the maritime MRV covers three gases — carbon dioxide, methane and nitrous oxide. Verified annual emissions reports are due by 31 March following each scheme year. Unlike the CO2-only aviation ETS, the maritime extension brings methane and nitrous oxide into scope.
Which flights does the UK ETS cover?
Under the Greenhouse Gas Emissions Trading Scheme Order 2020 (SI 2020/1265), aircraft operators are UK ETS participants covering UK domestic flights, flights between the UK and Gibraltar, and flights departing the UK to European Economic Area states and Switzerland.
It does not cover all international departures: arriving flights and most flights to non-EEA destinations are outside scope.
What are the UK ETS aviation deadlines?
There are two, a month apart, and they are separate obligations.
An aircraft operator must submit a verified annual emissions report covering the previous scheme year by 31 March, and must surrender enough UK allowances to cover that year's reportable emissions by 30 April.
Conflating the report deadline (31 March) with the surrender deadline (30 April) is a common error.
Do aircraft operators still get free allowances?
No.
Free allocation of allowances to aircraft operators has been phased out from 2026.
The free-allocation entitlement for aviation ran only for the 2021-to-2025 allocation period; from 2026 aircraft operators receive no free aviation allowances and must obtain allowances to meet their surrender obligation.
Free allocation for stationary installations follows separate rules and timelines.
What is CORSIA, and is it part of the UK ETS?
CORSIA is a separate, ICAO-origin offsetting scheme — not part of the UK ETS.
It is implemented in UK law by the Air Navigation (Carbon Offsetting and Reduction Scheme for International Aviation) Order 2021 (SI 2021/534), which requires aeroplane operators to monitor, record and report CO2 emissions from international flights using an eligible monitoring method, and to submit annually verified emissions reports to the Regulator.
It runs alongside the ETS under its own 2021 Order; the monitoring and verified-reporting duty applies regardless of whether an operator has reached the offset-surrender stage.
Who does the UK ETS maritime extension cover, and from when?
From 1 July 2026 the UK ETS is extended to maritime by the Greenhouse Gas Emissions Trading Scheme (Amendment) (Extension to Maritime Activities) Order 2026 (SI 2026/392), covering ships of 5,000 gross tonnage and above regardless of flag state.
Domestic maritime voyages and port activity are in scope from 1 July 2026, with offshore vessels added from 1 January 2027.
The 5,000 GT figure is gross tonnage, a measure of ship volume — not tonnes of CO2.
How does maritime MRV differ from aviation?
In two ways.
First, gases: unlike the CO2-only aviation ETS, the maritime extension brings three gases into scope — carbon dioxide, methane and nitrous oxide.
Second, entry: a maritime operator must apply for an emissions monitoring plan within 42 days of first maritime activity.
Verified annual emissions reports are due by 31 March following each scheme year, as for aviation.
The 42-day window and the three-gas basis are stated in SI 2026/392's schedule; check the instrument at clause level before quoting a paragraph number.
Related guides & references
UK Sustainability Reporting by Sector
The directory of industry-specific reporting regimes — screen, construction, aviation and maritime, energy networks
Scope 1, 2 and 3 Emissions
How fuel-burn emissions from flights and voyages sit in the emissions scopes
ESOS: Energy Savings Opportunity Scheme
The transport-inclusive energy-audit regime a large operator may also fall under, by size
SECR Compliance Guide
Companies Act energy and carbon reporting, separate from the ETS surrender obligation