Grandchild inheritance tax calculator (Ireland 2026)
Grandchildren inheriting in Ireland are Group B (€40,000 threshold) as the general rule. Section 42 CATCA 2003 creates a narrow exception: a minor grandchild whose parent has predeceased the grandparent qualifies for Group A (€400,000). This calculator applies the correct threshold for 2026.
Grandchildren inheriting from a grandparent in Ireland fall under Group B (the €40,000 threshold) as the general rule. This applies regardless of age. A narrow exception exists under Section 42 of the Capital Acquisitions Tax Consolidation Act 2003: a minor grandchild (under 18 and unmarried at the date of the inheritance) whose parent, being the grandparent's own child, has predeceased the grandparent, qualifies for Group A treatment (€400,000 threshold). In that specific case the grandchild "steps into the shoes" of the predeceased parent for threshold purposes.
If the grandchild's parent is still alive when the grandparent dies, the grandchild is Group B no matter how old they are. This is the situation most people are in, and it is the single most common mistake made with grandchild inheritance calculations.
This distinction matters most where the grandparent leaves a significant inheritance. A Section 42 minor grandchild inheriting €350,000 owes zero CAT because Group A is not crossed. A Group B grandchild (adult, or minor with parent still alive) inheriting the same amount owes 33% on €310,000, which is €102,300 of CAT.
How this calculator works
The calculator asks for the grandchild's age and whether the parent predeceased the grandparent, then applies the correct 2026 threshold. Section 42 Group A treatment is applied only where the grandchild is under 18 AND the parent predeceased. All other combinations default to Group B. It accounts for prior receipts in the same Group since 5 December 1991 and taxes the excess at 33%.
What to do with the number
If Section 42 applies and the inheritance is within the €400,000 Group A threshold, no CAT arises. For all other grandchild cases, the €40,000 Group B threshold applies and any inheritance above approximately €32,000 (80% of Group B) likely triggers an IT38 filing even before CAT is technically payable. 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.