IHT400 Calculator UK: Estimate Inheritance Tax in Minutes
Estimate the Inheritance Tax (IHT) due on an estate and see a breakdown relevant to the HMRC IHT400 form. This tool uses the latest checked UK Inheritance Tax thresholds for 2026/27: £325,000 nil-rate band, up to £175,000 residence nil-rate band, £2 million RNRB taper threshold, 40% standard rate and 36% reduced charity rate. Thresholds are currently fixed at these levels until 5 April 2031, but this tool remains an estimate and is not a substitute for HMRC guidance or professional advice.
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1. Assets
Advanced Assets (Business, etc.)
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2. Liabilities & Debts
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3. Exemptions
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4. Allowances
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5. Gifts (Last 7 Years)
Split by Year (Advanced Taper)
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6. Dates
Calculation Summary
IHT400 Ready Notes
- Chargeable Estate: £0
- Assets: Use IHT405 (property), IHT406 (bank/cash), IHT407 (personal goods), IHT409 (pensions), IHT411/412 (shares), IHT413/414 (business/agricultural assets) where relevant.
- Gifts: Complete Schedule IHT403 if applicable.
- Reduced Rate: Requires Schedule IHT430 if claiming 36%.
How this IHT calculator works
- Gross Estate: We sum all assets (property, cash, investments, etc.) declared in the IHT400 schedules.
- Net Estate: We deduct allowable liabilities (mortgages, debts, funeral expenses) specific to the estate.
- Exemptions: We subtract amounts left to a spouse/civil partner or UK charities, as these are typically tax-free.
- Nil-Rate Band (NRB): The standard £325,000 threshold is tax-free and is currently fixed until 5 April 2031. Any unused percentage from a predeceased spouse or civil partner can be added (Transferable NRB).
- Residence Nil-Rate Band (RNRB): An additional allowance of up to £175,000 if a qualifying residence is passed to direct descendants. It tapers by £1 for every £2 over the £2 million taper threshold.
- Gifts: We calculate gifts in the last 7 years. These use the NRB first. If gifts exceed the available NRB, taper relief may reduce the tax owed depending on how long ago the gift was made.
Key Terms Explained
Nil-Rate Band (NRB)
The tax-free threshold for Inheritance Tax. Currently £325,000 and fixed until 5 April 2031. Anything above the available allowances in the taxable estate is usually taxed at 40%.
Residence Nil-Rate Band (RNRB)
An extra tax-free allowance of up to £175,000 when a home is left to direct descendants, such as children or grandchildren. It tapers away by £1 for every £2 over £2 million.
Taper Relief
If taxable gifts were made 3 to 7 years before death and the available NRB has been used, the tax due on those gifts is reduced on a sliding scale.
Reduced Rate (36%)
If 10% or more of the net estate is left to charity, the IHT rate on the rest of the estate may drop from 40% to 36%.