How is tax residency determined in Ireland — the 183-day and 280-day rules?

Irish tax residency is determined by the number of days you are present in Ireland during a tax year. A day of presence means any part of the day when you are physically in Ireland.

You are automatically Irish tax resident for a year if you are present for 183 days or more in that year. You are also automatically resident if you are present for 280 days or more over the current and preceding tax year combined, with at least 30 days present in each year.

Ordinary residence is a separate concept: you become ordinarily resident after being resident for three consecutive years. Ordinary residence continues for three years after you stop being resident each year. Both residence and ordinary residence affect how Ireland taxes foreign income.

If you are resident but not domiciled in Ireland, foreign income is only taxable in Ireland if it is remitted to Ireland (the remittance basis). This makes Ireland potentially attractive for certain high-net-worth individuals. Irish domicile is acquired at birth or by long-term establishment and intention to remain.