Yes, you can usually claim Seafarers’ Earnings Deduction for earlier years, within limits. If you qualified and did not claim, the tax you overpaid is generally recoverable for up to four years from the end of the tax year concerned. After that it is gone.
Why so many seafarers have years unclaimed
SED is never given automatically. It has to be claimed on a Self Assessment return, and nobody tells you that when you sign your first contract. Seafarers who were taxed under PAYE, or who assumed being paid offshore meant nothing was due, commonly discover the deduction years into a career.
By that point there may be several years in which they qualified, paid tax they did not owe, and claimed nothing.
The time limits
| Your situation | Route | Time limit |
|---|---|---|
| Return filed, SED missed, still recent | Amend the return | 12 months from the 31 January filing deadline for that year |
| Return filed, SED missed, amendment window closed | Overpayment relief claim to HMRC | Four years from the end of the tax year |
| No return filed for that year | Register and submit the return | Four years from the end of the tax year |
The limit runs from the end of the tax year, not from today. Each 5 April, the oldest claimable year drops off permanently. If you think you have an old claim, the cost of waiting is a specific year’s tax, lost for good.
What an overpayment relief claim needs
Outside the amendment window, you cannot simply resubmit the return. A claim for overpayment relief has to be made in writing to HMRC and has to state that it is such a claim, identify the tax year, explain why tax was overpaid, give the amount, and include a signed declaration that the details are correct. A claim missing any of those is not a valid claim, and the clock keeps running while you fix it.
Evidence is the real constraint
The law may allow four years. Your paperwork may not. To claim an old year you still have to show an eligible period covering it — day by day, with the vessels named.
Discharge books usually survive. Flight bookings, boarding passes and payslips from three years ago often have not. Before writing a year off, it is worth checking what can be reconstructed: airline accounts and email confirmations, bank statements showing foreign spending, crewing agency records, and employer sign-on and sign-off letters, which can often be re-issued.
It has to be a claim you were entitled to
Backdating does not relax any condition. For each year you still need to have been an employee working on a ship, resident in the UK or an EEA state, within an eligible period, on qualifying voyages. The conditions are set out here.
Common questions
Can I claim SED for previous tax years?
Generally yes, for up to four years from the end of the tax year concerned, provided you met the conditions in that year and can evidence it.
I was taxed under PAYE for years. Can I get it back?
If you qualified for SED in those years and they are still in time, the claim produces a repayment of the tax deducted.
Will claiming old years trigger an enquiry?
HMRC can check any claim, and repayment claims for earlier years are looked at carefully. A claim that is correct and documented has nothing to fear from that. One that is not should not be made.
I have lost my records for one of the years. Is it worth trying?
Often a good deal can be reconstructed from airlines, banks, agencies and employers. Whether it is enough is a judgement to make before the claim goes in, not after HMRC asks.
Not sure where you stand?
Tell us your vessel, your dates and where you sailed. We will tell you plainly whether you have a claim.
Related: How to claim SED · Do I qualify? · Tax return checklist
Based on HMRC Helpsheet HS205 and HMRC guidance on Self Assessment corrections and National Insurance for mariners. Tax rules change and individual circumstances differ — this page is general information, not advice on your own position.
