Pillar Guide · Updated July 2026
Transferable Nil Rate Band: 2026/27 Inheritance Tax Guide
Married couples and civil partners can pass any unused Inheritance Tax nil rate band from the first death to the survivor's estate, potentially doubling the amount that can pass free of tax. This guide explains how the transfer works, how it is claimed, and how it combines with the Residence Nil Rate Band.
How the Transfer Works
Since 9 October 2007, when a married person or civil partner dies without using all of their Inheritance Tax nil rate band — commonly because assets passed to their spouse, which is an exempt transfer — the unused proportion can be transferred to increase the nil rate band available on the surviving spouse's death. Every estate has a nil rate band of £325,000 (frozen until April 2030); with a full transfer, a surviving spouse's estate can potentially have a nil rate band of up to £650,000 before Inheritance Tax applies.
Percentage, Not a Fixed Amount
The transfer is always calculated as a percentage of the nil rate band that was unused on the first death, not a cash amount. For example, if half the nil rate band was used by legacies to children on the first death, 50% of a nil rate band transfers, and it is then applied to whatever the nil rate band is worth at the time of the second death (even if this figure has changed since the first death).
Transferring the Residence Nil Rate Band
The Residence Nil Rate Band (RNRB), introduced in April 2017 for estates passing a qualifying home to direct descendants, works alongside the standard nil rate band and has its own transfer rules. Any unused percentage of the RNRB from the first death can transfer to the surviving spouse's estate, even if the first spouse died before April 2017 (before the RNRB existed), as long as the surviving spouse's own estate otherwise meets the RNRB conditions when they die. With both nil rate bands fully transferred, a surviving spouse's estate can potentially shelter up to £1 million from Inheritance Tax, subject to the RNRB taper for large estates.
How to Claim: Form IHT402
The transfer is not automatic — the executors of the second estate must actively claim it, normally using form IHT402 alongside the main Inheritance Tax account, providing details of the first spouse's date of death, their will or intestacy position, and how much (if any) of their nil rate band was used. HMRC will need evidence such as the first spouse's death certificate, will, and grant of probate or letters of administration if these are available.
Worked Example
Mrs Patel dies in 2018, leaving her entire estate to her husband, an exempt transfer, so none of her nil rate band is used — 100% is available to transfer. Mr Patel dies in 2026/27, leaving an estate of £700,000. His own nil rate band is £325,000, plus the full transferred nil rate band of £325,000 from his late wife, giving a combined £650,000 nil rate band before tax — leaving only £50,000 potentially subject to Inheritance Tax at 40% (before considering the Residence Nil Rate Band, which could reduce this further).
More Than One Previous Marriage
If someone was widowed and remarried, unused nil rate band percentages from each previous marriage or civil partnership can potentially be claimed on their death, but the combined transferable percentage is capped at 100% — meaning the maximum any estate can ever benefit from is two full nil rate bands (its own plus one transferred amount), never more.