iht calculator hmrc

What this HMRC IHT calculator does

This page helps you estimate inheritance tax in the UK using a practical, simplified model based on HMRC rules. If your estate may be above the nil-rate thresholds, a quick estimate is useful for planning: wills, gifting, trusts, life insurance, and charitable legacies.

The calculator combines the key moving parts that most families ask about:

• Standard Nil-Rate Band (NRB)
• Residence Nil-Rate Band (RNRB) where a home is left to direct descendants
• Possible transfer of unused allowances from a deceased spouse/civil partner
• Spouse/civil partner exemptions and charitable legacies
• A simple treatment of gifts made within seven years

Key HMRC inheritance tax thresholds (simplified)

1) Nil-Rate Band (NRB)

The standard NRB is commonly set at £325,000. Assets taxed above available allowances are typically charged at 40%.

2) Residence Nil-Rate Band (RNRB)

The RNRB can provide an additional allowance (commonly up to £175,000) when a qualifying residence passes to direct descendants. In broad terms:

• You must leave a qualifying home interest to eligible descendants.
• The allowance is limited by the value of the home interest passing on death.
• It can taper away for larger estates (often from around £2 million).

3) Transferred allowances between spouses/civil partners

If a spouse/civil partner died first and did not use their full allowance, the unused percentage can usually transfer. That can potentially double the NRB and RNRB for the second estate, depending on circumstances.

4) Tax rates

Inheritance tax is often charged at 40% on taxable value. A reduced rate of 36% may apply where enough of the net estate is left to charity. This calculator uses a simplified charity test to estimate whether the reduced rate may apply.

How to use this iht calculator hmrc tool

1. Enter your estimated gross estate value.
2. Add liabilities and deductible expenses.
3. Enter spouse/civil partner exempt transfers and charitable gifts.
4. Add recent chargeable gifts (last 7 years) as a planning estimate.
5. Enter residence value and tick whether it passes to direct descendants.
6. Add transferred allowance percentages if relevant.
7. Click Calculate IHT and review the breakdown.

Worked example

Suppose an estate is £850,000 with £20,000 in debts and no spouse exemption, with a qualifying home of £175,000 left to children. If no transferred bands are available and no charity gift is made, the calculator applies standard NRB and RNRB first, then taxes the remainder. This gives a quick planning figure and highlights whether modest gifting or will changes might reduce the final bill.

Planning ideas that can reduce inheritance tax

Use available exemptions while alive

• Annual gift exemption
• Small gifts exemption
• Normal expenditure out of income (where conditions are met)

Check will structure and ownership

How assets are owned and left in a will can materially affect available bands and reliefs. A professional review can ensure transferable allowances and residence rules are used correctly.

Review life insurance in trust

For some families, life cover written in trust can improve liquidity for tax payments and avoid increasing the taxable estate.

Consider relief-qualifying assets carefully

Business and agricultural relief may apply in specific cases. These rules are technical and should be confirmed with a qualified adviser.

Common mistakes people make

• Assuming a home always gets the residence nil-rate band.
• Forgetting taper effects on large estates.
• Ignoring gifts made within seven years.
• Not documenting transferable allowance evidence from first death.
• Using rough estimates without revisiting values yearly.

Frequently asked questions

Is this calculator an official HMRC calculator?

No. It is an independent estimator designed to mirror major HMRC concepts in an accessible way.

Does this include full gift taper calculations?

No. It treats chargeable lifetime gifts in a simplified way for planning. The exact tax due can vary by date, exemptions used, and interaction with the nil-rate band.

Can the charity rate reduction be different in real life?

Yes. HMRC charity reduced-rate rules involve detailed “component” calculations. This tool uses a simpler test suitable for rough forecasting.

Important disclaimer

This is a general educational tool and does not replace legal, tax, or financial advice. For probate, trust planning, or high-value/complex estates, consult a regulated UK tax adviser or solicitor and verify details directly with HMRC guidance.