How Much CAT on a €150,000 Inheritance from a Sibling? A Line-by-Line Group B Calculation
A sibling falls into the Group B threshold (€40,000). On a €150,000 inheritance with no prior Group B benefits, you deduct the threshold (€150,000 − €40,000 = €110,000) and apply the 33% CAT rate, giving a Capital Acquisitions Tax bill of €36,300. Below I walk through every line, the traps that change the number, and how to file the IT38.
Step 1 — Confirm the group: a brother or sister is Group B
CAT is charged by reference to your relationship to the disponer (the person the gift or inheritance came from). Revenue sorts every beneficiary into one of three groups, each with its own lifetime tax-free threshold:
| Group | Who it covers | Tax-free threshold |
|---|---|---|
| Group A | Child (incl. certain foster children) of the disponer; in some cases a parent inheriting from a child | €400,000 |
| Group B | Brother, sister, niece, nephew, lineal ancestor (e.g. grandparent) or lineal descendant (e.g. grandchild) | €40,000 |
| Group C | Any other relationship — cousin, friend, in-law, partner you are not married to or in a civil partnership with | €20,000 |
A brother or sister sits squarely in Group B, so the €40,000 threshold applies. These thresholds took effect for benefits taken on or after 2 October 2024 (Budget 2025). The threshold is a lifetime figure for that group — not an annual allowance — which matters for Step 3. Revenue: CAT group thresholds.
Step 2 — The base calculation: €150,000 from a sibling
Assume the simplest case first: this is the only Group B benefit you have ever received, and the full €150,000 is taxable (cash, after probate, no reliefs). CAT is charged at a flat 33% on the amount above the threshold — the rate that has applied to all benefits taken on or after 6 December 2012. Revenue: CAT rates.
Aoife inherits €150,000 in cash from her late brother Cillian in 2026. She has never received any other gift or inheritance from a Group B person. Her line-by-line calculation:
| Line | Description | Amount |
|---|---|---|
| A | Taxable value of the inheritance | €150,000 |
| B | Less Group B threshold | − €40,000 |
| C | Taxable excess (A − B) | €110,000 |
| D | CAT rate | × 33% |
| E | CAT payable (C × D) | €36,300 |
Aoife's CAT bill is €36,300, leaving her €113,700 net. There is no entry-level "nil band" beyond the €40,000 threshold and no graduated rate — every euro above €40,000 is taxed at the same 33%.
Step 3 — Subtract prior Group B benefits since 5 December 1991
This is where most people get the number wrong. The €40,000 is not a per-gift allowance — it is the total tax-free room you get from everyone in Group B combined, across your whole life. Under the aggregation rules, you must add back the taxable value of every prior gift or inheritance you received from a Group B disponer on or after 5 December 1991, and those prior benefits eat into the same €40,000. Revenue: CAT aggregation rules.
Same €150,000 inheritance — but suppose Aoife had already received a €25,000 gift from a niece in 2019 (also Group B). That €25,000 has already used part of her threshold:
| Line | Description | Amount |
|---|---|---|
| A | Group B threshold | €40,000 |
| B | Less prior Group B benefit (2019 gift) | − €25,000 |
| C | Threshold remaining for this inheritance | €15,000 |
| D | Inheritance value | €150,000 |
| E | Taxable excess (D − C) | €135,000 |
| F | CAT at 33% (E × 33%) | €44,550 |
The earlier €25,000 gift pushes Aoife's bill up by €8,250 (from €36,300 to €44,550), even though the inheritance itself is identical. Always reconstruct your full Group B history before trusting any headline figure.
Step 4 — Where the €3,000 small gift exemption fits (and where it does not)
The small gift exemption lets you receive up to €3,000 per calendar year from any one person completely free of CAT — and exempt gifts are ignored entirely for aggregation. But there are two limits that matter for our example:
- It applies to gifts only, not inheritances. An inheritance arises on death; it cannot be reduced by the small gift exemption. So the €150,000 sibling inheritance above does not get a €3,000 reduction.
- Where it does help is the prior-benefit history in Step 3: if a past €3,000-or-less annual gift was within the exemption, it never counted against your threshold in the first place.
Re-run Step 3, but Aoife's 2019 benefit was actually a €3,000 gift from her niece, not €25,000. Because €3,000 is fully covered by the small gift exemption, it is disregarded for aggregation. Her full €40,000 threshold is intact, so the inheritance is taxed exactly as in Step 2 — €36,300, not more. Had the niece given €5,000, only €3,000 would be exempt and €2,000 would reduce the threshold (giving €37,260 of CAT).
Revenue: Small Gift Exemption.
Step 5 — File the IT38 and pay by 31 October
You must file a CAT return on Form IT38 once the total taxable value of your benefits in a group exceeds 80% of that group's threshold — i.e. 80% × €40,000 = €32,000 for Group B. A €150,000 inheritance is far over that line, so a return is mandatory whether or not tax is due. Revenue: Filing obligations.
The deadline is driven by the valuation date (broadly, the date you become entitled to the benefit in possession — for an inheritance, usually the grant of probate). Both the return and the payment are due on the same "pay and file" date:
| Valuation date falls between… | Pay & file IT38 by… |
|---|---|
| 1 January – 31 August | 31 October of the same year |
| 1 September – 31 December | 31 October of the following year |
So if Aoife's valuation date is, say, March 2026, her IT38 and €36,300 payment are due by 31 October 2026. If it were October 2026, she would have until 31 October 2027. File through ROS or myAccount (or the paper IT38S for simple cases); interest runs from 1 November if you miss the date. Revenue: How and when do you pay and file?
- A sibling is Group B — a €40,000 lifetime threshold, not per gift.
- Base case: €150,000 − €40,000 = €110,000 × 33% = €36,300 CAT.
- Prior Group B benefits since 5 December 1991 reduce your remaining threshold and raise the bill.
- The €3,000 small gift exemption applies to gifts only — never to the inheritance itself — but it can keep small past gifts out of your aggregation history.
- File the IT38 once benefits exceed 80% of the threshold (€32,000), and pay by 31 October tied to the valuation date.
Frequently asked questions
How much CAT is due on €150,000 from a sibling?
With no prior Group B benefits, €150,000 minus the €40,000 Group B threshold is €110,000, taxed at 33% — a CAT bill of €36,300. Prior Group B gifts or inheritances received since 5 December 1991 reduce the available threshold and increase the tax.
Is a brother or sister Group A or Group B for CAT?
Group B. Group A (€400,000) is broadly for a child inheriting from a parent. Siblings, nieces, nephews, grandparents and grandchildren are Group B with a €40,000 threshold (effective for benefits taken on or after 2 October 2024).
Can the €3,000 small gift exemption reduce tax on an inheritance?
No. The small gift exemption applies to gifts only, not to inheritances, so it cannot reduce the taxable value of a €150,000 inheritance. It is useful for lifetime planning and for keeping small past gifts out of your aggregated Group B history.
Do I have to file an IT38 if the inheritance is below the threshold?
You must file once the total taxable value of your benefits in a group exceeds 80% of that group's threshold — €32,000 for Group B — even if no tax is ultimately payable. A €150,000 inheritance always requires an IT38.
When is the CAT payment and IT38 actually due?
It depends on the valuation date. If the valuation date is between 1 January and 31 August, pay and file by 31 October that same year. If it falls between 1 September and 31 December, you have until 31 October of the following year.
What if I received an earlier gift from another Group B relative?
Aggregate it. Add the taxable value of every Group B benefit received since 5 December 1991. Those prior amounts use up the same €40,000, so the remaining threshold for the current inheritance is smaller and the 33% charge applies to a larger excess.
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