Ireland's 280-Day Look-Back: Two Short Years Can Make You Resident
Quinn Moran · Published
Yes. Under section 819 of the Taxes Consolidation Act 1997 you are Irish tax resident for a year if you spend 183 days or more in Ireland in that calendar year, or 280 days or more across that year and the previous one combined. Two years of 150 and 140 days total 290, so the second year is resident even though neither year reached 183. A year with 30 days or fewer cannot be resident and is ignored for the 280-day test.
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Most conversations about Irish tax residence start and stop at 183 days. That number is real, but it is only one of two tests in section 819 of the Taxes Consolidation Act 1997, and the second is the one that catches people. Ireland also looks back: 280 days across the current tax year and the one before it makes you resident for the current year, even if neither year reached 183 on its own.
This post is about that second test: how the look-back arithmetic works, the 30-day floor that switches it off, and the counting rules that decide what goes into each total. It is written for people whose Irish days are spread across years rather than concentrated in one: Irish citizens abroad who come home often, consultants with recurring Dublin trips, and anyone who has left Ireland and still visits. The complete rule set, including the election into residence and split-year treatment, is in our Ireland 183-day tax residency guide.
Two tests, one calendar year
Ireland's tax year is the calendar year, so every count runs from 1 January to 31 December. Within that frame, section 819 sets two separate thresholds, and meeting either one is enough.
| Test | What is counted | Threshold | Effect |
|---|---|---|---|
| 183-day test | Days present in the current tax year | 183 or more | Resident for the current year |
| 280-day look-back | Days present in the current year plus the preceding year | 280 or more combined | Resident for the current (later) year only |
| 30-day floor | Days present in the current year | 30 or fewer | Not resident for that year; days ignored for the 280-day test |
The 183-day test is self-contained. Reach 183 in a year and that year is resident; nothing else in the calculation matters. The look-back is different, because it carries one year's days into the next year's answer. That is what makes Ireland a two-year counting exercise rather than a one-year one.
How the look-back arithmetic works
The guide's worked example: 150 days in Ireland in 2025, and 140 days planned for 2026. Neither year reaches 183. Combined, they total 290, which crosses 280, so 2026 is a resident year under the look-back. At 129 days in 2026, the combined total would be 279, one below the threshold, and 2026 would not be resident under either test.
Three features of the test show up in that example.
It only ever points forward. The look-back attributes residence to the later of the two years. The 150 days in 2025 do not make 2025 resident; they make 2026 easier to tip over. Whether 2025 itself is resident depends on its own count and on 2024.
It rolls. Each year is paired with the one before it. So 2026's days are tested twice: once as the current year in the 2025 and 2026 pair, and again as the preceding year in the 2026 and 2027 pair. A heavy year in Ireland affects the following year's answer, not just its own.
Neither year has to be large. Back-to-back 170-day years total 340, well past 280, although each year sits comfortably under 183. A pattern that looks moderate year by year can be resident in the second year on the arithmetic alone.
That last point is why the January reset misleads. The 183-day count does go back to zero every 1 January. The 280-day total does not, because last year's days are already in it.
The 30-day floor
Section 819(2) contains the one exception that cuts through the look-back. If you are present in Ireland for 30 days or fewer in a tax year, you are not resident for that year, whatever the previous year looked like, and those days are ignored when the 280-day test is applied.
The floor is a hard line rather than a sliding scale. At 30 days it applies. At 31 days it does not, and the look-back runs in the ordinary way against the previous year's total. Because part days count in full, the gap between those two outcomes can be a single short visit.
The floor also works in one direction only. It can stop a year from being resident; it cannot undo a year that is already resident under either test.
What goes into each total
Both tests are only as reliable as the day count feeding them, and Ireland's counting rule is broad.
Any part of a day is a day. Section 819(4) as originally enacted counted presence at midnight. Revenue guidance confirms that from 2009 onwards you are present for a day if you are in the State at any time during it. An arrival at 23:30 is a day. A departure at 06:00 is a day. A same-day return trip to Dublin is one full day, not zero.
Airside transit is not presence. Passing through an Irish airport or port without entering through immigration does not count toward either total.
Force majeure relief is narrow. If events such as severe weather or an aircraft breakdown prevent a planned departure, Revenue will not count the day after the intended departure, provided the only reason for being in Ireland is the emergency. The days before it still count.
Northern Ireland is not the State. Section 819 counts presence in the State, meaning the Republic of Ireland. Days in Northern Ireland do not enter either Irish total. They are UK days, relevant to the UK statutory residence test instead, and the UK Statutory Residence Test calculator covers that side. A cross-border pattern therefore produces two separate counts under two separate systems.
The practical effect of part-day counting is that a pattern of frequent short trips generates more days than nights. Anyone who thinks in nights spent in Ireland will consistently undercount against both the 183 and the 280.
Where the look-back leads: ordinary residence
The look-back decides residence one year at a time. Section 820 adds a longer memory. Three consecutive years of residence make you ordinarily resident from the start of the fourth year, and that status only ends after three consecutive years of non-residence.
While ordinarily resident but non-resident, a person remains taxable on worldwide income, with limited exceptions for foreign trades, employment duties performed entirely abroad, and other foreign income up to 3,810 euro. Anyone resident or ordinarily resident is also within the Irish capital gains tax net on worldwide disposals.
In day-count terms, a year that falls under both section 819 thresholds is not the same as a year outside the Irish charge. The year-by-year status from section 819 and the three-year status from section 820 are separate records. Departure from Ireland starts the second clock running; it does not stop the first one from mattering. The Ireland residency guide sets out how sections 819 and 820 interact in full.
What a day count does not settle
Day counts answer the section 819 question. Several things that change what residence means in practice are not day counts at all.
- Domicile. Residents who are not Irish domiciled can use the remittance basis, paying Irish tax on foreign income and gains only when they are brought into Ireland. Domicile is a separate concept from residence and is not determined by counting days.
- Treaty residence. If Ireland and another country both treat someone as resident, the tie-breaker tests in the relevant double taxation agreement allocate treaty residence: permanent home, centre of vital interests, habitual abode, nationality. Treaty relief has to be claimed and proven, not assumed.
- Split-year treatment. Under section 822, a qualifying arriver or leaver is treated as resident for only part of the year for employment income. It applies to employment income only, and after a Finance Act 2024 change it can be claimed in the tax return for arrivals and departures from 2025 onward. Whether someone qualifies is a determination about their circumstances, not a day count.
Ireland is one of several countries where 183 days is not the whole test. Our comparison of countries where 183 days is not the rule sets Ireland's look-back alongside the others.
The burden of proof and the two-year record
Enforcement runs through self-assessment. The burden is on the individual to establish their day count and satisfy an authorised officer of Revenue if their status is questioned, and disputes are appealable under section 824 within two months of a decision.
Put together, part-day counting, a test that reaches back a full year, and a burden of proof on the individual mean the record that matters is not one year's total but two consecutive years of dated presence, each day attributable to a place. Boarding passes, ferry bookings and accommodation records are the kinds of evidence that establish where someone was. Our post on proving where you were without passport stamps covers how that evidence holds up now that stamps are disappearing.
iReside records which country you were in on each calendar day from your iPhone's location, in the background. Day counts for each rule you track are computed from that record continuously, so the previous year's days are already in the record on 1 January rather than being reconstructed later from receipts. The day-by-day record exports as CSV or PDF, with each day labelled by where it came from: GPS, manual entry, or a planned future day. For how day-count tests like Ireland's fit together across countries, see how international tax residency works.