Guide
HS205 Seafarers’ Earnings Deduction worksheet
What HMRC working sheet HS205 is, how seafarers use it to work out an eligible period, and what to enter on the Self Assessment additional information pages.
Read the guideSeatax
Seafarer tax guides
Pages built around the questions Google, AI overviews and crew actually ask — then the Seatax solution.
Guide
Seafarers’ NT tax code and form R44
How UK seafarers request tax code NT so PAYE is not deducted, when HMRC will issue it, and how form R44 fits with a Seafarers’ Earnings Deduction claim.
Read the guideGuide
Seafarers’ 12-mile limit: what “outside the UK” means for SED
For Seafarers’ Earnings Deduction, outside the UK means beyond UK territorial waters — generally 12 nautical miles — at midnight. How the 12-mile rule works for North Sea and coastal work.
Read the guideGuide
North Sea seafarers’ tax and SED
Tax for North Sea crew: when support vessels can claim Seafarers’ Earnings Deduction, why midnight position sheets matter, and when Schedule 27 knocks the claim out.
Read the guideGuide
Seafarers and student loan repayments
Do seafarers repay student loans if they claim Seafarers’ Earnings Deduction? How taxable income, SLC and HMRC interact when SED reduces employment income to nil.
Read the guideGuide
Do seafarers pay National Insurance?
Seafarers’ Earnings Deduction is an income tax relief. It does not exempt National Insurance. How residency, flag, employer location and UK waters affect seafarer NI.
Read the guideGuide
Seafarers’ Self Assessment tax return
Why UK resident seafarers must file Self Assessment even if paid gross, how SED is claimed on the return, and what Seatax files as your agent.
Read the guideGuide
Overdue seafarer tax returns
Behind on HMRC Self Assessment after time at sea? How Seatax brings overdue seafarer years up to date, including SED claims where you still qualify.
Read the guideGuide
Cruise ship crew tax UK
Do cruise ship crew pay UK tax? When Seafarers’ Earnings Deduction can apply to UK resident cruise employees and why you still need a Self Assessment return.
Read the guideGuide
Offshore wind farm crew tax and SED
Tax for wind-farm vessel crew: when CTVs, SOVs and support ships can claim Seafarers’ Earnings Deduction, and when UK waters or installation work blocks the relief.
Read the guideGuide
FPSO and offshore installation tax: why SED often fails
FPSOs, FSUs, MODUs and production platforms are generally not ships for Seafarers’ Earnings Deduction. How Schedule 27 affects oil and gas workers.
Read the guideGuide
Royal Fleet Auxiliary tax and Seafarers’ Earnings Deduction
Royal Fleet Auxiliary employees can claim Seafarers’ Earnings Deduction if they meet the tests. Royal Navy Crown employees cannot.
Read the guideGuide
Seafarers and UK tax residency
SED is for UK residents (and certain EEA residents). How the statutory residence test, days in the UK, and ‘too few UK days’ can wreck a seafarer tax claim.
Read the guideGuide
Foreign port voyage rule for Seafarers’ Earnings Deduction
Why SED usually needs a voyage that begins or ends at a foreign port, why UK-to-UK passages fail, and how HMRC’s day-of-absence practice changed.
Read the guideGuide
Seafarers’ half-day rule explained
The SED half-day rule: no UK visit over 183 consecutive days, and UK days must not exceed half the eligible period. Why a simple day count is not enough.
Read the guideGuide
Can seafarers get a tax refund?
When UK seafarers get tax back: PAYE refunds, SED claims on Self Assessment, and why a refund is not HMRC agreeing your seafarer claim forever.
Read the guideGuide
Cadet and college time: seafarer tax and SED
How cadetships, study leave and college attendance affect Seafarers’ Earnings Deduction. Shore training is usually not duties on a ship.
Read the guideGuide
Seafarer tax return deadlines
Self Assessment deadlines for seafarers: 31 October for paper returns, 31 January for online filing and payment. When to get your pack to Seatax.
Read the guideGuide
What is a ‘ship’ for Seafarers’ Earnings Deduction?
UK tax law does not define ship for SED, but offshore installations are excluded. Which vessels qualify and which fail, including dry dock.
Read the guideGuide
HMRC enquiries into seafarer tax and SED
What happens if HMRC checks a Seafarers’ Earnings Deduction claim, what evidence they ask for, and how Seatax handles investigations during enrolment.
Read the guideGuide
Superyacht crew UK tax
UK tax for superyacht deckhands, stewards, engineers and captains. Double tax agreements, Self Assessment and Seafarers’ Earnings Deduction.
Read the guideGuide
Oil and gas support vessel tax
SED for AHTS, PSV, ERRV and other oil and gas support vessel crew, versus platform and FPSO workers who usually cannot claim.
Read the guideGuide
Seafarers’ Earnings Deduction eligibility
The SED eligibility checklist used in Google AI overviews: ship, 365-day eligible period, UK or EEA residence, foreign-port voyage, half-day rule, and who is excluded.
Read the guideGuide
How seafarers lose Seafarers’ Earnings Deduction
The usual ways SED fails: not yet 365 days, 183-day visits, half-day rule, no foreign port, not a ship, non-residence, college time, and dry dock.
Read the guideEnrol 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.