What is Seafarers Earnings Deduction? (SED)

Seafarers earnings deduction (SED) is a tax relief if you work on a ship

To get your 100% claim of Seafarers Earnings Deduction, you must:

  1. Work on a ship (though what HMRC define as an ‘offshore installation’ does not count- see theSED Terminologypage to have this explained).
  2. You have to have worked for 365 days as a seafarer starting and finishing with a period abroad (offshore work or holiday) BUT, you can’t break the half-day rule, (which basically means your days spent in the UK must be less than half of the total qualifying period (the 365 days). – this is explained in more detail here *
  3. You have to visit at least one foreign port during your qualifying period, which is referred to as a ‘qualifying voyage’.

What documents do I need at hand to claim? Page

You will need to present certain documents to claim what you are owed by HMRC. These are listed below.

  • air tickets or other travel vouchers, boarding passes
  • hotel bills or other receipts
  • passports and visas
  • seafarer’s discharge book
  • freeboard logs of the ships you carried out duties on
  • salary statements



• Working on a ship
• Must be employed (not self employed)
• Be UK resident
• Initially complete a qualifying period of 365 days
• At least 183 days must be outside of the UK
• Visit at least one foreign port per employment
• Cumulative days in the UK should not be greater than the days out of the UK