You move to Ireland. The IRS stays.
The United States taxes its citizens wherever they live, and Ireland taxes the people who live there. Planned well, the two systems sit side by side and you pay once. Planned late, the gaps cost real money.
The IRS stays
The US is one of very few countries that tax by citizenship. The US-Ireland tax treaty of 1997 says so in its own words: under the saving clause in Article 1(4), the United States may tax its citizens “as if the Convention had not come into effect”. You keep filing a US return every year, with an automatic extension to June 15 for Americans abroad and October 15 with a further extension.
In practice the Irish tax you pay becomes a credit against your US tax on the same income, and because Irish rates are generally higher, the foreign tax credit often leaves little or nothing to pay in the US on income Ireland has taxed. The choice between the credit and the foreign earned income exclusion is explained under FEIE or foreign tax credit, and the whole picture of filing from abroad under US tax obligations abroad.
Ireland taxes residents
Irish tax residence follows the days you spend in the country, and the year you arrive can be split so that Ireland reaches only the part after your move. Our pages on split-year treatment and on ordinary residence set out the tests. Income that arises in Ireland, such as Irish rent or an Irish salary, is taxed in Ireland in full.
Non-dom for an American
Ireland separates residence from domicile, the country you regard as your permanent home. An American who moves to Ireland usually arrives with a domicile in their home state. As long as Revenue accepts that you are not domiciled in Ireland, Ireland taxes your foreign income and gains only when you bring them into Ireland: the remittance basis. The mechanics, and what counts as bringing money in, are on our page on the remittance basis.
For an American, three things change the picture:
- The US keeps taxing everything. Income you leave in the US escapes Irish tax but stays fully taxable in the US. The remittance basis decides which country taxes a dollar, never whether it is taxed.
- Article 24(6) of the treaty. Where Ireland taxes you on the remittance basis, treaty relief applies only to the part “remitted to or received in” Ireland. Money left in the US loses the treaty’s protection.
- Domicile can move. Domicile follows your intention to stay for good. A retiree or an Irish citizen who settles in Ireland permanently can acquire an Irish domicile of choice, and from then on the remittance basis ends. That is why dom and non-dom belong in one plan, and why non-dom status is never a promise for life.
FBAR and Form 8938
Once you open Irish accounts, they join your US reporting. Both reports cover the same accounts in different ways, and both carry penalties far larger than the tax involved.
| Report | When it applies |
|---|---|
| FBAR (FinCEN 114) | Your accounts outside the US exceeded $10,000 combined at any point in the year |
| Form 8938, single | Foreign financial assets above $200,000 on the last day of the year, or above $300,000 at any time |
| Form 8938, married filing jointly | Above $400,000 on the last day of the year, or above $600,000 at any time |
Source: IRS, Summary of FATCA reporting for U.S. taxpayers (reviewed 19 September 2026); FBAR threshold 31 CFR 1010.306(c). Retrieved 9 November 2026.
The details are under FBAR filing and FATCA and Form 8938. Why Washington still taxes you abroad, in plain words, is in The Brief on citizen-based taxation.
Leaving your state
Federal tax follows your passport; state tax follows your domicile. States such as California and New York can keep treating you as a resident when your ties stay behind: a home, a driver’s license, a voter registration. A clean state exit is planned before the move: what you keep, what you close and which date you can prove. The state rules are set out under state tax after moving abroad.
Pensions and funds
Two parts of an American’s wealth need their own pages. Social Security and pensions are taxed under special treaty rules, and they interact with the remittance basis in a way that surprises most retirees. And investment funds walk into two tax regimes at once: the PFIC and Irish fund trap is the most expensive mistake we see.
More for Americans moving to Ireland
Both tax systems, planned before you leave
Relocation USA to Ireland covers your Irish registration and dom and non-dom planning, your state residency exit, the treaty position of your Social Security and pensions, a fund review and your US reporting set up. $7,500 per household.