Who qualifies
A merchant seafarer employed on a sea-going ship registered in any EU or EEA state who is at sea for at least 161 days in the tax year on qualifying voyages.
How to claim
Submit Form SEA1 through myAccount, supported by a discharge book or sea-time letter from the shipping company confirming dates and voyages.
Detailed explanation
The Seafarer Allowance is a deduction from gross income rather than a tax credit, but it functions similarly in reducing tax payable. From 2026 the allowance is 6,350 euro per year, deducted from total assessable income before tax. Qualifying voyages must begin or end in a foreign port, ruling out vessels that operate exclusively within Irish waters. The seafarer must be employed under a contract of service, so self-employed fishermen claim the Fishers Tax Credit instead. The 161-day test is calculated on calendar days at sea or on qualifying voyages, including days spent travelling to or from a vessel based abroad on instruction of the employer. Days of sick leave or shore leave do not count. The seafarer must be tax resident in Ireland. Where a seafarer also qualifies for the Foreign Earnings Deduction or Special Assignee Relief Programme, only one relief can be claimed in the same year. The deduction reduces the basis on which USC is also calculated for the seafarer. Officers and ratings on cruise ships, tankers, container vessels and bulk carriers all potentially qualify provided the voyage and day-count tests are met. Spouses or partners of seafarers can be jointly assessed and benefit from any unused tax bands generated by the deduction.
Worked example
Sinead is a chief officer on an EU-flagged container ship and earns 70,000 euro with 200 days at sea on qualifying voyages. After the 6,350 deduction her assessable income is 63,650 euro. Tax: 20 percent on 44,000 = 8,800, plus 40 percent on 19,650 = 7,860, less credits 4,000 leaves 12,660 euro, saving her about 2,540 euro versus claiming nothing.