The transferable nil rate band lets the estate of a surviving spouse or civil partner claim the percentage of the nil rate band in force at the first death that the first spouse or civil partner did not use, applied to the £325,000 band at the second death (2026/27, frozen to 5 April 2031), so a widow or widower's estate can have up to £650,000 free of inheritance tax. The claim is made on the second death by the personal representatives, on form IHT402 or in the probate application, and it is not automatic. A percentage transfers, so a first death in 1995 with everything left to the spouse gives a second £325,000 today, not a second £154,000. Correct as at 13 September 2026.
How do you work out the transferable nil rate band?
You take the nil rate band in force at the first death, subtract the part that was used, express what is left as a percentage of that first-death band to 4 decimal places, and apply the percentage to the £325,000 band (2026/27) in force at the second death.
Form IHT402 walks through it box by box, deducting chargeable gifts in the 7 years before the first death, taking the percentage to 4 decimal places, never more than 100% and not rounded up, and rounding the transferred amount up to the pound. HMRC's manual gives the formula at IHTM43020.
| First death | Band then | What used it | Unused | Transferred to a 2026/27 death | Total band |
|---|---|---|---|---|---|
| September 1995 | £154,000 | Everything to the spouse | 100% | £325,000 | £650,000 |
| June 2006 | £285,000 | £57,000 of legacies to the children, rest to the spouse | 80% | £260,000 | £585,000 |
| 2010 | £325,000 | A £400,000 estate left entirely to the children | 0% | Nil | £325,000 |
Thresholds from GOV.UK's Inheritance Tax thresholds page; method from IHTM43020 and form IHT402.
What if the first death was decades ago, or before inheritance tax existed?
The claim covers any first death, including deaths under Capital Transfer Tax (13 March 1975 to 17 March 1986) and Estate Duty (before 13 March 1975), and the amount on which no tax or duty was charged then counts as the nil rate band (IHTM43060). The only date test is that the survivor died on or after 9 October 2007.
The trap in very old deaths is the spouse exemption: none before 22 March 1972, limited to £15,000 until 12 November 1974, unlimited since, so an estate left wholly to a wife in 1970 may have used its band. If the old grant shows tax or duty as paid there is nothing to transfer. HMRC accepts that evidence may not survive and that personal representatives may complete the claim as well as they can on the information available (IHTM43011).
What if the first spouse left gifts or legacies to other people?
Anything the first spouse left to someone other than their spouse, civil partner or a charity, and any chargeable gifts they made in the 7 years before they died, used part of their band, and only the remaining percentage transfers. A nil rate band discretionary trust in an older will typically used the whole band, so 0% transfers, which is one reason a claim can be smaller than expected.
A deed of variation made within 2 years of the first death may have changed who inherited and goes in with the claim. Any residence nil rate band used at a first death on or after 6 April 2017 goes in box 12 and is added back, because value covered by that band did not use the nil rate band. How gifts are counted is in the 7 year rule.
What if the survivor remarried, or had more than one spouse?
A claim can be made in respect of each late spouse or civil partner, but the total increase is capped at 100% of the band at the survivor's death, so the most any estate can have is two bands, £650,000 in 2026/27 (IHTA 1984 section 8A(5)). Where a widow remarries and dies first, her estate claims from her first husband, and her second husband's estate can later claim her unused percentage; a missed claim on her death may reduce what his estate gets (IHTM43035). Divorce is different: the couple must have been married or in a civil partnership when the first death occurred.
How do you claim it: IHT402, or the excepted estate route?
The personal representatives claim on form IHT402, filed inside the IHT400 account, within 24 months after the end of the month in which the survivor died (or, if later, 3 months from when the personal representatives first act) (IHTM43007). For an excepted estate where the death was on or after 1 January 2022 the claim is made when you apply for probate instead; that route covers an estate of £650,000 or less where the whole of one late spouse's or civil partner's threshold is unused and transferred (a partial percentage, like the 80.5194% in the example below, needs the full IHT400 and IHT402), provided the estate meets HMRC's other excepted estate conditions.
HMRC has a discretion to accept a late claim, and only a discretion. The tax itself is due by the end of the sixth month after the month of death, a separate date: a survivor who dies on 10 February 2027 leaves an estate whose tax is due by 31 August 2027 and whose IHT402 is due by 28 February 2029.
What evidence do you need for the first death?
IHT402 must be sent with a copy of the grant to the first estate, or the death certificate if no grant was taken out, the will if there was one, and any deed of variation (IHT402, HMRC 04/25). The form also asks who benefited under the will or intestacy, whether joint or trust assets were in the first estate, chargeable gifts in the 7 years before that death, and the date and place of the marriage. Where records are gone it points to the solicitor who acted, the executors, the probate records search and the General Register Office.
Example
Example. A man dies in September 1995 leaving legacies of £30,000 to his two children and the rest to his wife. The nil rate band for 6 April 1995 to 5 April 1996 was £154,000, so £124,000 was unused: 124,000 divided by 154,000, times 100, is 80.5194% to 4 decimal places, not rounded up.
His widow dies in 2026/27 leaving £700,000 to the children, with no home in the estate, so no residence nil rate band. Her executors claim on IHT402. Box 20 is £325,000; box 21 is £325,000 times 80.5194%, which is £261,688.05, rounded up to £261,689; the total band is £586,689.
Tax with the claim: £700,000 less £586,689 is £113,311, at 40% is £45,324.40. Without the claim: £700,000 less £325,000 is £375,000, at 40% is £150,000. The claim changes the tax by £104,675.60, and it needs the 1995 grant or death certificate and the 1995 will.
Does the residence nil rate band transfer as well?
Yes. The unused percentage of the £175,000 residence nil rate band (2026/27, frozen to 5 April 2031) transfers by the same method, a first death before 6 April 2017 gives 100% of it unless the first estate was worth more than £2 million (the taper then reduces what transfers), and it is a separate claim on IHT436, covered in our residence nil rate band guide.
What to do now
You can order the two death certificates and the marriage certificate, search the probate records for the first grant and will, read it for legacies and trusts, and put a first number on the second estate with our inheritance tax calculator. A nil rate band trust in the first will, an Estate Duty death, a remarriage, doubt over whether the estate is excepted and any claim near the 24 month date need an adviser.
A surviving spouse reading ahead is in inheritance tax planning territory: a will leaving everything to the spouse preserves 100% of the band for transfer; a nil rate band legacy uses it.
What we do on the second death
We ask first for the two death certificates, the marriage or civil partnership certificate, and whatever survives from the first estate: the grant, the will and any deed of variation.
We work out the unused percentage from the band in force at the first death, allowing for legacies to anyone other than the spouse, chargeable gifts in the previous 7 years and any residence nil rate band used. We then say which route the estate is on: where it qualifies as excepted, the claim goes in the probate application and we do not prepare an IHT400 that is not required; otherwise we prepare the IHT400 with IHT402 inside it, file within the 24 months and answer HMRC's questions.
If the first grant shows tax or duty was paid, or the couple were not married or in a civil partnership at the first death, there is no claim to make and we will say so. The firm is licensed by the ICAEW for non-contentious probate; disputed estates sit with litigation solicitors.
Frequently Asked Questions
Not during your lifetime. Your executors claim the unused percentage of her band on your death, on IHT402 with the IHT400 or in the probate application, within 24 months after the end of the month in which you die.
Each parent has a £325,000 nil rate band (2026/27), so up to £650,000 where the unused band transfers, and up to £1 million where both residence nil rate bands also apply and the home passes to children; see our residence nil rate band guide.
Yes. Any first death qualifies, including Estate Duty and Capital Transfer Tax deaths, and the amount on which no tax or duty was charged counts as the band. The 9 October 2007 test applies to the second death only.
24 months after the end of the month in which the surviving spouse or civil partner died, or 3 months from when the personal representatives first acted if later. HMRC has a discretion to extend it.
Talk to Chloe Symmonds about a transferable nil rate band claim
The first conversation covers when the first spouse died, what their will or intestacy did, what paperwork survives and the size of the second estate. Chloe Symmonds, Senior Manager, handles the firm's inheritance tax and probate files. Call 020 8554 2135, email info@visionconsulting.co.uk or use the contact page.
About Vision Consulting. Vision Consulting is a firm of chartered accountants and registered auditors, regulated by ICAEW, with offices in the City of London (the Gherkin, 30 St Mary Axe), the West End (33 Cavendish Square) and Gants Hill, Ilford. The firm provides year-end accounts, bookkeeping, payroll and tax compliance, including Making Tax Digital and VAT, for individuals, landlords, directors and businesses. Its specialist teams provide audit and assurance (company and charity audits and audit-exemption advice), probate and estate administration (the firm is licensed for non-contentious probate), inheritance-tax and estate planning, HMRC tax investigations and voluntary disclosures, property and landlord taxation, and corporation-tax and company advisory.
By the Vision Consulting team.
This is general information, not advice. Your position depends on your circumstances. Speak to us before acting on anything here.