Guide
Northern Ireland and the border
Many people live on one side of the border and work, shop or see family on the other. The two countries count those days differently, and one day can count for both.
Northern Ireland is the UK
For tax, Northern Ireland is part of the United Kingdom, whatever your citizenship. Being Irish, British or both doesn't change where a day is counted. A day in Belfast or Newry is never a day in Ireland for Revenue; it can be a UK day for HMRC.
Two different counts
- Ireland: any part of a day in the State counts as an Irish day. See Irish tax residence.
- The UK: a day counts as a UK day if you are in the UK, Northern Ireland included, at midnight at the end of it. See what counts as a UK day.
So a day that starts in one country and ends in the other can be an Irish day and a UK day at the same time, or one and not the other.
Examples
| The day | Irish day? | UK day? |
|---|---|---|
| Live in Newry, work in Dundalk, home each evening | Yes: in the State during the day | Yes: in Northern Ireland at midnight |
| Live in Lifford, shop in Strabane, home by 10pm | Yes | No: not in the UK at midnight |
| Live in Derry, visit family in Buncrana for the afternoon | Yes | Yes |
| A whole day in Belfast, staying the night | No | Yes |
| Fly out of Dublin, never leaving the airside area | No: airside transit | No |
Someone who lives in Newry and works in Dundalk five days a week builds about 230 Irish days a year as well as a full year of UK days. Days alone could then make them resident in both countries. Where that happens, the tax treaty between Ireland and the UK decides where the income is taxed, and Ireland also has a relief for some cross-border workers. A qualified adviser can tell you how they apply to you.
Proving which side you were on
There are no passport checks on the land border, so no official record shows when you crossed. Your own record has to: phone location, receipts, tolls, work records. The guide to proving your days covers what tax offices ask for.
RezTally's map follows the border to a few metres, from OpenStreetMap, so a night in Lifford counts as Ireland and a night in Strabane as the UK. It counts an Irish day by any part of the day and a UK day by midnight, so a cross-border day shows in both counts.
Sources: Revenue's Tax and Duty Manual Part 34-00-01 (section 819) and HMRC's RDR3 (the Statutory Residence Test).