Sibling inheritance tax calculator (Ireland 2026)

A brother or sister inheriting from a sibling in Ireland falls under the Group B threshold of €40,000 for 2026. This calculator shows the CAT owed at 33% on the excess, with aggregation of prior Group B gifts and inheritances since 5 December 1991.

Brothers and sisters inheriting from a sibling in Ireland are Group B for Capital Acquisitions Tax. The 2026 Group B threshold is €40,000, and any excess is taxed at 33%. Half-siblings are treated the same as full siblings under the CATCA 2003.

Sibling inheritances are among the most common Group B scenarios, particularly where one sibling dies unmarried or without children and leaves their estate to a brother or sister. The low threshold combined with typical estate values, often including a house, means CAT is frequently payable.

How this calculator works

The calculator applies the 2026 Group B threshold of €40,000 to the inheritance, after deducting any prior Group B receipts (from this sibling or any other Group B donor since 5 December 1991). The remainder is taxed at 33%. The calculator also flags when an IT38 filing is required.

What to do with the number

If the estimated CAT is above €20,000, the Complete Bundle is the right pack: it includes the full per-beneficiary calculation, Dwelling House Exemption assessment if the inheritance includes a house the beneficiary lived in, and IT38 draft returns. If the brother or sister lived in the deceased's home as their only home for three or more years, DHE may eliminate the CAT charge on the house entirely; the assessment is included in the Complete Bundle.

This calculator is a preparation tool using Irish tax rates and rules for 2026. It is not legal or tax advice. For complex estates, consult a solicitor or tax adviser. All values are estimates based on the information you provide.