When you inherit assets abroad, two countries can claim tax on the same benefit. One is the country where the asset sits. The other is Ireland, which taxes its residents on inheritances from anywhere in the world. This guide explains how Ireland prevents that double charge. For the wider picture, start with our pillar guide to cross-border inheritance in Ireland.
Ireland's approach rests on two legal mechanisms: treaty relief under section 106 of the Capital Acquisitions Tax Consolidation Act 2003, and unilateral relief under section 107. Which one applies depends entirely on the country the asset came from. We set out both below, with worked figures and the steps to claim.
What double taxation on inheritance means
Double taxation on inheritance happens when the same gift or inheritance is taxed in two countries because of the same event. Ireland charges Capital Acquisitions Tax (CAT) — the tax on gifts and inheritances — on its residents' worldwide benefits, while many countries also tax assets situated within their own borders.
Irish CAT is charged at 33% on the value of an inheritance above your tax-free group threshold. As of June 2026 the thresholds are €400,000 (Group A), €40,000 (Group B), and €20,000 (Group C). Without relief, a beneficiary could pay 33% to Ireland on top of whatever the foreign country has already taken.
Ireland's two relief mechanisms
Ireland relieves double taxation through two distinct routes set out in the Capital Acquisitions Tax Consolidation Act 2003. Treaty relief, under section 106, applies a bilateral convention given the force of law. Unilateral relief, under section 107, applies where no treaty exists but a comparable foreign tax has been paid.
The treaty network for inheritance tax is small. Ireland has estate and inheritance tax treaties with only two countries: the United Kingdom and the United States. Although Ireland has a wide network of income tax treaties, that network does not extend to CAT — for every other country, you rely on unilateral relief.
Treaty relief
Section 106 CATCA 2003 (treaty given force of law)
United Kingdom and United States only
Foreign tax under the terms of the relevant convention
Unilateral relief
Section 107 CATCA 2003
Every other country (e.g. France, Spain, Australia)
Foreign tax similar in character to estate, gift, or inheritance tax
No relief
None available
Where no comparable foreign tax was paid
Nothing — only one country taxed the benefit
The three possible outcomes for a foreign inheritance: treaty relief, unilateral relief, or no relief where only one country taxes the benefit.
| Mechanism | Legislative Basis | Countries Covered | What It Credits |
|---|---|---|---|
| Treaty relief | Section 106 CATCA 2003 (treaty given force of law) | United Kingdom and United States only | Foreign tax under the terms of the relevant convention |
| Unilateral relief | Section 107 CATCA 2003 | Every other country (e.g. France, Spain, Australia) | Foreign tax similar in character to estate, gift, or inheritance tax |
| No relief | None available | Where no comparable foreign tax was paid | Nothing — only one country taxed the benefit |
The UK and US inheritance tax treaties
The Ireland-UK treaty covers Irish CAT and UK Inheritance Tax. It reconciles two different bases of taxation: Ireland taxes by reference to the residence of the disponer or beneficiary, while the UK taxes by reference to domicile — the country a person treats as their permanent home. Inheritances from the UK are the most common cross-border scenario we coordinate.
The Ireland-US convention covers Irish Inheritance Tax and US federal estate tax. It does not apply to US gift tax, and it does not cover death duties imposed by individual US states. This matters for inheritances such as US shares held in an Irish estate, where the federal position and any state position can differ.
Under both treaties, the credit is the lower of the foreign tax or the Irish tax at the effective rate, and it cannot exceed the Irish CAT actually paid on the property. You must claim within six years of the date of the event, supported by documentation confirming the foreign tax paid.
Taxes covered
Irish CAT and UK Inheritance Tax
Irish Inheritance Tax and US federal estate tax
Gifts covered
Inheritances; gift tax treated under the convention
No — the convention does not apply to gift tax
Sub-national taxes
Not applicable
No — US state death duties are excluded
Basis of taxation reconciled
Irish residence vs UK domicile
Irish residence vs US situs and citizenship
Credit calculation
Lower of UK or Irish effective rate; capped at Irish tax paid
Lower of US or Irish effective rate; capped at Irish tax paid
Claim deadline
Six years from the date of the event
Six years from the date of the event
Key differences between Ireland's two inheritance tax treaties. Both cap the credit at the Irish CAT paid on the foreign property.
| Feature | Ireland–UK Treaty | Ireland–US Treaty |
|---|---|---|
| Taxes covered | Irish CAT and UK Inheritance Tax | Irish Inheritance Tax and US federal estate tax |
| Gifts covered | Inheritances; gift tax treated under the convention | No — the convention does not apply to gift tax |
| Sub-national taxes | Not applicable | No — US state death duties are excluded |
| Basis of taxation reconciled | Irish residence vs UK domicile | Irish residence vs US situs and citizenship |
| Credit calculation | Lower of UK or Irish effective rate; capped at Irish tax paid | Lower of US or Irish effective rate; capped at Irish tax paid |
| Claim deadline | Six years from the date of the event | Six years from the date of the event |
Worked example: foreign tax credited against Irish CAT
A worked example shows how the credit reduces, but rarely eliminates, the Irish charge. Imagine an Irish-resident beneficiary inherits US shares worth €200,000 from a US estate. US federal estate tax of €24,000 is paid, and the Irish CAT on those shares works out at €30,000 at the effective rate.
Value of US shares inherited
€200,000
US federal estate tax paid on the shares
€24,000
Irish CAT on the shares (effective rate applied)
€30,000
Treaty credit (lower of the two taxes)
€24,000
Net Irish CAT payable on the shares
€6,000
Illustrative figures only. The treaty credit equals the lower of the two taxes (€24,000), leaving €6,000 of Irish CAT payable on the shares.
| Step | Amount |
|---|---|
| Value of US shares inherited | €200,000 |
| US federal estate tax paid on the shares | €24,000 |
| Irish CAT on the shares (effective rate applied) | €30,000 |
| Treaty credit (lower of the two taxes) | €24,000 |
| Net Irish CAT payable on the shares | €6,000 |
The credit is the lower of the two taxes — here, the €24,000 US tax — leaving €6,000 of Irish CAT to pay on the shares. If the foreign tax had instead been €40,000, the credit would still be capped at the €30,000 of Irish CAT on that property. The €10,000 excess is not refundable.
What happens when there is no treaty
For inheritances from countries other than the UK and US, Ireland gives unilateral relief under section 107 CATCA 2003. This applies where a foreign tax similar in character to estate duty, gift tax, or inheritance tax has been paid on property situated in that country — for example, succession tax in France or Spain.
Unilateral relief works on the same lower-of-two-taxes principle as the treaties. The credit equals the lower of the foreign tax paid or the Irish CAT attributable to the foreign property, and it cannot exceed the Irish CAT on that property. Documentation from the foreign tax authority confirming the tax paid is essential.
How to claim double taxation relief
You claim both treaty and unilateral relief on your IT38 return, filed through Revenue Online Service (ROS) or myAccount. You will need to establish the value of the foreign asset in euro at the valuation date and obtain a certificate or receipt from the foreign tax authority confirming the tax paid. Filing the IT38 is one of the duties that fall to executors when an estate has foreign assets.
For both the UK and US treaties, the claim must be made within six years of the date of the event. Keep all supporting documentation for at least six years in case Revenue queries the relief. Currency conversion uses the exchange rate on the valuation date, not the date of death or the date you receive the assets.
When to get professional advice
Double taxation relief is one of the more technical areas of Irish tax. The interaction between two tax systems, differing valuation rules, currency conversion, and the cap on credits means a small error can leave relief unclaimed or a return understated. Professional review is particularly worthwhile when an estate spans more than one country.
We are a coordination platform, not a law or accountancy firm — we connect you with the right specialists and keep the process moving. Our tax specialist reviews estates for cross-border exposure. You can start with our free assessment to see what your estate needs, or call us on (01) 578 1570 if you would prefer to talk it through first. For a sense of the wider costs involved, see our guide to probate costs in Ireland.