Grandchild inheritance tax calculator (Ireland 2026)

Grandchildren inheriting in Ireland fall under Group A if they are under 18 (€400,000 threshold) or Group B if they are 18 or over (€40,000 threshold). This calculator handles both cases for 2026.

Grandchildren have a split CAT treatment in Ireland based on age. Minor grandchildren (under 18) are treated as Group A, with the same €400,000 threshold as children of the deceased. Adult grandchildren (18 or over at the date of the inheritance) fall under Group B, with the lower €40,000 threshold.

This distinction matters most where the grandparent leaves a significant inheritance. A minor grandchild inheriting €350,000 owes zero CAT because the Group A threshold is not crossed. An adult grandchild inheriting the same amount owes 33% on €310,000, which is €102,300 of CAT.

How this calculator works

The calculator asks whether the grandchild is under 18 at the date of the inheritance, and applies the correct Group A or Group B threshold for 2026. It accounts for prior Group A or Group B receipts since 5 December 1991 and taxes the remainder at 33%.

What to do with the number

If the grandchild is under 18 and the inheritance is within the Group A threshold, no CAT arises. If the grandchild is an adult and the inheritance is above €30,000 (approaching 80% of Group B threshold), an IT38 filing is likely required. The Complete Bundle includes the per-beneficiary calculation, the IT38 drafts, and checks for reliefs such as Dwelling House Exemption and Section 72 policies.

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.