Image credit to: Sven Hansche / Shutterstock.com Introduction The UK Emissions Trading Scheme (UK ETS) was extended to domestic maritime activity on 1 July 2026, following the EU ETS, FuelEU Maritime and IMO measures. Charterers and traders must keep these regimes separate in their planning and contracts. Charterers will not usually answer to the UK regulator, but the commercial burden may pass down the charter chain. The practical questions are which emissions are covered, what the charter requires and how the figures will be checked and corrected. What the UK scheme actually catches The scheme is initially domestic and activity-based. It generally applies to ships of 5,000 GT and above on voyages between UK ports, including return voyages, and to UK port activity.  A UK-foreign voyage is not itself caught, only its UK port emissions are.  Domestic UK voyages and UK port emissions attract a 100% surrender obligation. On UK Northern Ireland voyages, all emissions are monitored and reported, but a 50% surrender deduction applies. It covers CO 2 , methane (CH 4 ) and nitrous oxide (N 2 O) on a tank-to-wake basis. Whether it applies at anchorage depends on its location and the port boundary and may be voyage or port activity. Charterers should not assume every anchorage period is treated alike. Who is responsible and who really pays The regulated person is the maritime operator, normally the registered owner. If the registered owner does not perform the duties of an ISM company, then the UK ETS responsibilities can be delegated to the ISM company, which requires a legally binding arrangement. A conventional time or voyage charterer does not become the operator merely by agreeing to fund allowances. The charterparty can nevertheless place the cost on the charterer. If allowances or payments are not provided for, the owner remains exposed towards the authorities and has a contractual remedy. The charterer's liability likewise depends on the agreed wording of th