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Guide ยท UK tax
If you are UK tax resident and working on yachts, Seafarers Earnings Deduction (SED) can wipe out the UK income tax on your salary earned at sea. This guide covers who qualifies, how the day counting works, and how to claim, so you understand your position long before you hand in notice.
Seafarers Earnings Deduction is a UK tax relief that lets qualifying seafarers deduct 100% of their foreign earnings from a ship based employment from UK income tax. In practice, most UK resident yacht crew who qualify pay no UK income tax on their salary earned at sea.
It is not automatic. You have to claim it, usually through Self Assessment, and HMRC expects you to be able to prove every part of your claim.
The broad conditions: you must be UK tax resident for the year you are claiming, you must work on a ship (yachts count), and your duties must be performed wholly or partly outside the UK. Port operations staff and people who work only on vessels in UK waters are generally excluded.
Most full time crew on ocean going yachts meet the employment conditions. The part that decides almost every claim is the day counting rule below.
To qualify for a tax year, you need a qualifying period of at least 365 days, made up of days when you are absent from the UK. Within that period, you must spend at least 183 days outside the UK, and no single visit to the UK can last more than 183 consecutive days.
Crucially, at no point may your UK days reach half or more of the total days in the period. HMRC calls this the half rule. A qualifying period can span two tax years, which often helps crew who joined or left a vessel mid year.
Keep a completed Seafarers Deduction record for each employment, your discharge book or sea service testimonials, employment contracts, payslips, and a personal travel diary of every UK entry and exit with dates.
Flight confirmations, boarding passes and passport stamps all support your day count. If you have not kept these from day one, start now: reconstructing years of travel after the fact is where most claims get painful.
SED is claimed through a Self Assessment tax return, in the employment pages with the foreign earnings deduction. If you have never filed a return, you need to register for Self Assessment with HMRC first, which can take a few weeks.
The deadline for online returns is 31 January following the end of the tax year. If HMRC owes you a refund for a previous year, you can generally go back four tax years.
Assuming non residency: being paid offshore does not make you non resident. UK tax residence is decided by the Statutory Residence Test, not by where your salary lands.
Day counting errors on visits home: a UK day generally counts if you are in the UK at midnight. Arriving at 23:00 and leaving the next morning is still one UK day.
Leaving it until you exit: the cheapest time to understand your position is while you are still earning at sea, not the month after you hand in notice.
Week 8 of The Crossing Method is a full tax masterclass with specialists who work with yacht crew every day, covering SED, residency and the mistakes to avoid, alongside financial planning, career strategy and the identity work of leaving. Twelve weeks, one plan, everything covered before you need it.
Explore The Crossing MethodThis guide is general information, not tax advice. Tax rules change and your position depends on your circumstances; always confirm details with HMRC guidance or a qualified tax adviser before acting.