Since 1 July 2026 the UK Emissions Trading Scheme has covered domestic shipping. Any vessel of 5,000 gross tonnage or above running between UK ports, returning to the port it left, or sitting at a UK berth now generates a liability that has to be monitored, verified plus paid for in allowances. The first reporting period is a six-month stub, 1 July to 31 December 2026, and the first allowances are not surrendered until 30 April 2028 under a one-off double deadline that covers both 2026 and 2027.
I have watched operators treat that 2028 date as breathing room. It is not. The obligation that bites this year is the emissions monitoring plan, which has to be filed within 42 days of a company's first maritime activity under the scheme, and a plan filed late cannot be backdated to fix data you never collected. This guide sets out the scope, the deadlines, the exemptions plus how the UK scheme sits alongside the European one.
What is in scope, and at what share
Coverage is defined by voyage geography rather than by flag or ownership, so a foreign-flagged ship on a UK domestic leg is caught exactly as a British one is.
| Activity | Share of emissions covered, percent |
|---|---|
| Voyage between two UK ports | 100 |
| Voyage starting and ending at the same UK port | 100 |
| Emissions at berth in a UK port | 100 |
| Voyage between Great Britain and Northern Ireland | 50 |
The 50 percent treatment of Great Britain to Northern Ireland traffic is the detail most often missed in budgeting. It applies in both directions, so a ro-ro operator on a Cairnryan or Liverpool rotation books half the carbon cost of an equivalent Scottish mainland run of similar length.
The threshold is 5,000 gross tonnage, which excludes most workboats, small coasters plus harbour craft. Cargo and passenger ships above the line are both in, and the size test is per vessel while the compliance obligation sits at company level.
The dates that actually bind
Four deadlines run the scheme, and only one of them is the well-publicised surrender date.
| Requirement | Deadline |
|---|---|
| Registry holding account for a maritime operator | From 1 July 2026 |
| Emissions monitoring plan submitted for approval | Within 42 days of first maritime activity |
| Verified emissions report for the 2026 stub period | 31 March 2027 |
| Allowance surrender for 2026 plus 2027 together | 30 April 2028 |
The emissions monitoring plan is compiled at company level rather than ship by ship, which sounds like a simplification and behaves like a trap for operators whose fleets use different fuel measurement methods. One plan has to describe the monitoring approach across every vessel in scope, so a mixed fleet needs its methods harmonised before filing rather than after.
The double surrender in April 2028 exists because the government accepted that operators needed lead time on data systems. It is a cash flow gift plus an accounting hazard: two years of liability landing on one date makes the provision easy to under-reserve.
Who regulates you depends on where you are
The shipping company holds the obligation, and the regulator that approves plans, receives reports plus imposes penalties varies by geography. The Environment Agency handles England and, importantly, operators based outside the UK. The Scottish Environment Protection Agency, Natural Resources Wales plus the Department of Agriculture, Environment and Rural Affairs in Northern Ireland cover their own jurisdictions.
That allocation matters for a non-UK operator running Scottish routes: the regulator is the Environment Agency by virtue of the company being foreign, not the Scottish agency by virtue of the water the ship floats on. Getting the counterparty right at registration saves a resubmission cycle.
Failure to surrender allowances on time draws civil penalties aligned with those applied across every other UK ETS sector, and regulators publish the names of operators subject to emissions penalties. The reputational element is deliberate. In carbon compliance a published list does more work than the fine attached to it.
What it costs, and why the reserve price is not the price
The scheme's auction reserve price rose from 22 to 28 pounds per tonne on 8 April 2026, reflecting accumulated inflation since the mechanism was set up in 2021, and from 1 January 2027 it adjusts annually with inflation. That figure is a floor beneath auctions rather than a market quote, so it belongs in a downside model, not in a budget.
For frequent-call operators the practical approach is the one European ferry companies adopted after 2024: buy allowances forward against projected emissions on the same cycle as bunkers, instead of treating each voyage as a separate carbon purchase. Fuel efficiency work pays twice under this design, once at the pump and once at surrender, which is the argument I use with operators who see the scheme purely as a tax. Bunker pricing context by hub sits in our ranking of the largest bunkering ports.
Exemptions worth checking before you model
Two carve-outs remove entire route categories from the calculation.
- Lifeline ferry services. Routes serving Scotland's islands plus certain peninsular communities are exempt, which takes a large share of the domestic ferry network out of scope.
- Fishing activity. Fish-catching plus fish-processing vessels are excluded regardless of tonnage.
- Vessels under 5,000 gross tonnage. Outside the scheme entirely, which shapes tonnage decisions for new coastal services.
- International voyages. A leg from a UK port to a foreign port is not covered by UK ETS, though it may be covered elsewhere.
How this interacts with the European scheme
Operators trading both sides of the Channel now sit under two carbon markets with different scopes. The EU scheme reached its full phase-in for shipping in 2026 after starting at 40 percent of emissions in 2024 and 70 percent in 2025, and it covers voyages into and out of the European Economic Area at 50 percent plus intra-EEA voyages at 100 percent. The UK scheme covers domestic UK activity only.
A Rotterdam to Immingham run therefore falls under the EU scheme at half its emissions and outside the UK scheme completely, while a Southampton to Belfast run falls under the UK scheme at half. Neither scheme double-counts the other's territory, so the compliance work is duplication of process rather than of cost: two registries, two monitoring plans, two verification cycles. The wider regulatory direction, including the global mechanism still under negotiation, is covered in our guide to the IMO Net-Zero Framework, and the parallel carbon-at-the-border regime for goods is in our UK CBAM preparation guide.
- File the monitoring plan inside 42 days. The clock starts at first maritime activity, and missing data cannot be reconstructed later.
- Open the registry account now. Holding accounts have been available since 1 July 2026 and surrender is impossible without one.
- Reserve for two years of allowances by April 2028. The one-off double deadline merges 2026 and 2027 liabilities.
- Model above 28 pounds per tonne. That is the auction floor after the April 2026 increase, not a market price.
- Check the Northern Ireland discount. Great Britain to Northern Ireland voyages are covered at 50 percent, unlike other domestic legs.
Common questions
When did UK ETS start applying to ships? From 1 July 2026, for vessels of 5,000 gross tonnage and above on domestic UK voyages and at UK berths. The first reporting period is the six months to 31 December 2026.
Who is responsible for compliance? The shipping company, not the individual vessel. Plans are approved and penalties imposed by the Environment Agency for England and for operators based outside the UK, by the Scottish Environment Protection Agency, Natural Resources Wales or the Northern Ireland department elsewhere.
When must allowances be surrendered? By 30 April 2028 for the 2026 and 2027 schemes combined, a one-off double deadline. Verified emissions reports are due by 31 March following each reporting period, so 31 March 2027 for the 2026 stub.
Are ferries exempt? Some are. Services to Scotland's islands plus certain peninsular communities are exempt, as are fish-catching and fish-processing vessels. Other domestic ferry routes above 5,000 gross tonnage are in scope, with Great Britain to Northern Ireland sailings covered at 50 percent.
What does an allowance cost? The auction reserve price rose to 28 pounds per tonne on 8 April 2026 from 22 pounds, and it indexes to inflation annually from 1 January 2027. That reserve is a floor rather than the traded price, so budgets should sit above it.
Sources: UK Department for Energy Security and Net Zero maritime compliance guidance for the UK Emissions Trading Scheme, DNV and Lloyd's Register technical notices on the 1 July 2026 maritime expansion, International Carbon Action Partnership records on the auction reserve price increase of 8 April 2026, plus published regulator allocation for England, Scotland, Wales and Northern Ireland. Scheme parameters reflect rules in force on 21 August 2026.