Decorative chart. It shows a passage plan crossing the Bay of Biscay, passing the Dover Strait and running north-east through the North Sea emission control area to an EU port call. That is the voyage GreenETS reports on. No information here is missing from the text below.
UK ETSallowances and cost
Shipping entered the UK Emissions Trading Scheme on 1 July 2026. It is not the EU scheme with different numbers. The UK takes all of a domestic voyage and none of an international one, and there is no phase-in to grow into.
What the UK actually charges
UK ETS applies to ships of 5,000 gross tonnage and above, whatever the flag. It covers carbon dioxide, methane and nitrous oxide, as carbon dioxide equivalent, and one allowance covers one tonne.
In scope, at 100%
A voyage between two UK ports of call, and all the time a ship spends in a UK port. That covers lying alongside, manoeuvring inside the port, waiting at anchor within port limits and hotelling. The berth is caught even when the ship arrived from abroad and leaves for abroad.
In scope, at 50%
A voyage between a Northern Ireland port of call and a Great Britain one, in either direction. The emissions are still monitored and reported in full. The deduction applies to surrender alone, and it does not reach the time in port at either end.
It exists because EU ETS charges only 50% of a Republic of Ireland to Great Britain voyage, Great Britain being a third country to it. Without the deduction the same crossing would cost twice as much from Belfast as from Dublin.
Not in scope
The sea passage of any voyage with one end outside the UK, the EEA included. The Isle of Man, the Channel Islands and Gibraltar are not UK ports for this Order either, so a Liverpool to Douglas passage is outside it. The time in Liverpool is not: a UK berth is caught whatever the passage at either end of it was.
Three things that are not like EU ETS
There is no phase-in
The EU ramped shipping in at 40% of 2024, 70% of 2025 and everything after. The UK starts at 100% and always has.
International voyages are outside, not halved
The EU takes 50% of a voyage with one end in a third country. The UK takes none of the passage. It takes only the UK berth at either end of it.
The first scheme year is six months
2026 runs 1 July to 31 December. Running it as a calendar year roughly doubles the answer. Allowances for 2026 and 2027 both fall due on 30 April 2028.
Extending UK ETS to 50% of international voyages from 2028 has been consulted on and not legislated. Nothing on this page prices it. If it happens, the Northern Ireland deduction goes with it and those voyages return to a 100% surrender obligation, because the disparity it was written to close will have closed on its own.
Work out the allowances
One line per sailing. Where it went, what it burned getting there, and what it burned alongside.
Worked examples
Allowances and cost
- Belfast United Kingdom — Northern Ireland
- Londonderry United Kingdom — Northern Ireland
Monitored and reported
69.96
tonnes CO₂e in scope, before any deduction
Allowances to surrender
69.96
UKAs, one per tonne CO₂e
Cost at £49.41
£3456.54
due 30/4/2028, alongside the other stub-period year
| Leg or berth | CO₂e, t | Share | UKAs | Cost, £ | Why |
|---|---|---|---|---|---|
| Belfast to Londonderry | 56.94 | 100% | 56.94 | 2813.20 | Both ends are UK ports of call. |
| At Londonderry | 13.02 | 100% | 13.02 | 643.34 | Time in a UK port is in scope in full. |
| Total entered | 69.96 | 69.96 | £3456.54 |
Emission factors come from SI 2020/1265 Schedule 2A (inserted by SI 2026/392), Part 6 Table C2. Methane and nitrous oxide are converted at the Order’s own 100-year GWPs of 28 and 265.
Every figure, and where it came from
Belfast to Londonderry
| Fuel | Tonnes | CO₂e, t | Methane slip, t | Factors |
|---|---|---|---|---|
| HFO — ISO 8217 grades RME to RMK | 18.00 | 56.936 | — | CO2: Table C2 · CH4: Table C2 · N2O: Table C2 |
At Londonderry
| Fuel | Tonnes | CO₂e, t | Methane slip, t | Factors |
|---|---|---|---|---|
| MDO / MGO — ISO 8217 grades DMX to DMB | 4.00 | 13.020 | — | CO2: Table C2 · CH4: Table C2 · N2O: Table C2 |
Where Table C2 prints TBM or N/A, paragraph 36(3) directs the operator to the highest default in the same column for that fuel class, and where a whole column is blank for a class, to the least favourable fossil value. So in those columns a blank costs more than a number, never less. The same paragraph exempts the slippage column, which is why an LPG or ammonia row with N/A there carries no slip at all rather than the worst of the four.
What this figure assumes
- That nothing chargeable was burned at the port the itinerary starts from. Every other port’s time alongside is asked for as the arrival of the leg that reached it, but the first departure port has no leg arriving at it. If it is a UK port and the ship burned fuel there, add a leg into it and that berth is counted.
- That the fuel entered is what the ship burned on the legs and at the berths as split above. UK ETS is monitored per voyage and per port call, by one of the four methods the Order allows, and verified by a UKAS-accredited verifier.
- That no emissions reduction claim applies. An eligible fuel named in a Ministerial Direction can be zero-rated for CO₂, but only for CO₂, and only on a verified claim with certificates behind it. The methane and nitrous oxide are charged either way.
- That the ship is not one the Order excludes. The exclusions cover government and military, law enforcement, search and rescue, fishing and fish processing, publicly funded research, Scottish ferry services, wooden ships of primitive build, ships without mechanical propulsion, and offshore ships until the end of 2026.
- That EU ETS is dealt with separately. A voyage with one EEA end is 50% chargeable there and not chargeable here. UKAs and EUAs are not interchangeable, and the UK–EU linkage is not concluded.
- An estimate, not a filing. The allowance figure a regulator acts on is the verified one in your annual emissions report.
Running it on your fleet
This page prices one itinerary you type in. GreenETS does the same from the noon, departure, arrival and port reports your ships already file. Every voyage is classified and every berth counted, alongside EU MRV, EU ETS, FuelEU Maritime, IMO DCS and CII on the same data.