Seatax
North Sea seafarers’ tax and SED
North Sea crew are a high-risk group for SED. Support vessels outside 12 NM can generate outside-UK days. Platforms, FPSOs and many installations cannot. Mixing the two is how refunds get clawed back.
Pain
North Sea work feels ‘offshore’. HMRC may still treat you as in the UK, or not on a ship at all.
Solution
We check the vessel type and the 12-mile positions before we claim SED.
Ship versus installation
Offshore installations used in oil and gas are not ships for SED. Fixed and floating production platforms, FSUs, FPSOs and MODUs generally fail the test. A vessel that can navigate under its own power may still qualify if the other SED tests are met.
See Schedule 27 and our ship-definition guide before you assume the relief applies.
Evidence HMRC ask for
For North Sea duties you should keep midnight position sheets showing whether the ship is in or outside 12 NM at midnight, plus draught/freeboard sheets showing dates of entering and leaving the UK or the twelve-mile limit.
This page is general information based on published HMRC guidance, not personal tax advice. Seatax will apply the rules to your sea service after you enrol. Fees from £275 including VAT per return.
Questions people ask
Can ERRV and supply-boat crew claim SED?
Sometimes, if the vessel is a ship and you meet the eligible period, half-day rule and foreign-port tests. We review the vessel before claiming.
What if I work on a platform?
Platforms are typically offshore installations, not ships. SED is usually not available. We will tell you if another basis applies.
Enrol with Seatax
Ready to put your seafarer tax in order?
Fees from £275 including VAT per tax return. Download the pack, or call us and we will deal with your enquiry within 24 hours.