Transferable Nil Rate Band UK (2026): How Spouses Pass Unused IHT Allowance
Updated 13 May 2026 · 8 min read · England & Wales
Married couples and civil partners have a significant IHT advantage: any unused nil rate band from the first death can be transferred to the survivor’s estate. Used correctly, this can mean up to £650,000 in combined NRB — or £1 million when the residence nil rate band is included — before a penny of IHT is due.
What is the nil rate band and why does it matter?
The nil rate band (NRB) is the threshold below which no inheritance tax is charged on a deceased person’s estate — currently £325,000 and frozen at this level until at least April 2030. Assets above the NRB are taxed at 40% (or 36% if 10%+ of the estate is left to charity).
Every individual has their own NRB. But when a married person or civil partner dies and leaves everything to their spouse, the spouse exemption means no IHT is charged and none of the NRB is used. The unused NRB can then be transferred to the survivor under the rules in s8A–8C IHTA 1984 (introduced by Finance Act 2008).
How the TNRB works: a simple example
| Scenario | First spouse’s estate | NRB used | % transferred | Survivor’s total NRB |
|---|---|---|---|---|
| All to spouse | £500,000 (all to survivor) | £0 | 100% | £650,000 |
| Half to spouse, half to children | £400,000 (£200,000 to children) | £200,000 | 38.5% | £450,125 |
| Pre-death gifts used NRB | £100,000 gift within 7 years | £100,000 | 69.2% | £549,920 |
| Full transfer + RNRB | All to spouse; qualifying home | £0 | 100% NRB + 100% RNRB | £1,000,000 |
How the percentage transfer works
The TNRB transfers a percentage of the NRB — not a fixed cash amount. This is advantageous: if the NRB rises between first and second death, the survivor gets the benefit of the higher NRB applied to the transferred percentage.
Formula: % transferable = (NRB at first death − NRB used) ÷ NRB at first death
On second death: Additional NRB = % transferable × NRB at second death
The maximum transfer is 100% — even if multiple previous spouses died with unused NRBs. The RNRB operates on the same basis and is claimed separately.
How to claim the transferable nil rate band
The claim is made on the second death — there is nothing to do at the time of the first death (though keeping records is important). The executor of the surviving spouse’s estate completes:
- Form IHT402 — Claim to transfer unused nil rate band (submitted with the IHT400)
- Evidence of the first spouse’s NRB usage: their death certificate, marriage certificate, and IHT papers or probate documents from the first death
There is no time limit for claiming, but HMRC will not automatically calculate or apply the TNRB — the executor must claim it. Estates where the TNRB makes the estate non-taxable may still need to file IHT400 if assets exceed the NRB before the transfer is applied.
The residence nil rate band: also transferable
The residence nil rate band (RNRB) — up to £175,000 per person for qualifying residential property left to direct descendants — is also transferable between spouses on the same percentage basis. The RNRB transfer is claimed on form IHT435. Combined with a full NRB transfer, this means qualifying couples can pass up to £1 millionfree of IHT on the second death (£650,000 NRB + £350,000 RNRB).
The RNRB is tapered at £1 for every £2 of net estate above £2 million — large estates may not benefit from the full RNRB.
Will planning and the TNRB
The introduction of the TNRB in 2007 made the old “nil rate band discretionary trust” less essential for couples with modest estates. However, nil rate band discretionary trusts remain useful for: very large estates; care home fee planning; asset protection; or where the survivor might remarry. A well-drafted will should explicitly address whether to rely on the TNRB or to use a trust structure — taking into account the size of the estate, IHT exposure, and the nature of the assets.
Frequently asked questions
What is the transferable nil rate band?
The transferable nil rate band (TNRB) is the ability to transfer any unused portion of the deceased's nil rate band (NRB) to the estate of their surviving spouse or civil partner (s8A–8C IHTA 1984, inserted by Finance Act 2008). The NRB is the threshold below which no IHT is charged — currently £325,000 per person. If the first spouse to die used none of their NRB (for example, because everything passed to the surviving spouse under the spouse exemption), 100% of the NRB can be transferred. On the second death, the surviving spouse's estate effectively has up to £650,000 NRB before IHT is charged. The transfer is of the unused percentage of the NRB at the time of the first death — so the actual amount transferred increases if the NRB rises between first and second death.
How much nil rate band can be transferred?
The percentage of the NRB unused on the first death is transferred — not the absolute amount. Example: if the NRB was £300,000 when the first spouse died and they used £75,000 of it (leaving £225,000 unused), 75% of the NRB is transferred. On the second death, if the NRB is £325,000, the survivor has their own £325,000 plus 75% × £325,000 = £243,750 — total £568,750. The maximum transfer is 100% of the NRB — you cannot transfer more than 100% even if the first spouse had unused RNRB as well. The residence nil rate band (RNRB) is separately transferable: the RNRB transfer percentage is calculated on the same basis, potentially giving the survivor £325,000 + £325,000 NRB plus £175,000 + £175,000 RNRB = £1,000,000 total before IHT.
Can you claim the transferable nil rate band from multiple deceased spouses?
Yes — the rules allow transfers from more than one deceased spouse or civil partner. A person who has been widowed twice (or more) can claim transferred NRB from each deceased spouse, up to a maximum of one additional NRB (100%) in total. So the maximum NRB on the second death, regardless of how many previous spouses died with unused NRB, is 200% — £650,000 at 2026/27 rates. Each previous marriage is assessed separately and the combined transferred percentage is capped at 100%.
How do you claim the transferable nil rate band?
The TNRB claim is made on the second spouse's death — not at the time of the first death. The executor of the surviving spouse's estate claims the transfer on form IHT402 (Claim to transfer unused nil rate band), submitted with the IHT400 (full IHT return). Required evidence: the first spouse's death certificate; the marriage or civil partnership certificate; evidence of the unused NRB on the first death (usually the first spouse's probate or administration papers, their IHT form, or confirmation of any gifts made). There is no time limit for the claim, but it must be made as part of the surviving spouse's estate administration. Executors should claim proactively — HMRC does not prompt.
Does the first spouse need to have made a will for the TNRB to apply?
No. The TNRB applies regardless of whether the first spouse died testate (with a will) or intestate (without a will). What matters is how much of the NRB was used on the first death — which depends on what assets passed outside the spouse exemption. If everything passed to the surviving spouse on first death (by will, joint tenancy survivorship, or intestacy), 100% of the NRB is unused and transferable. The TNRB also applies to civil partnerships and to marriages that ended in death (not divorce — a divorced spouse cannot claim a TNRB).
How does the transferable nil rate band interact with the residence nil rate band?
The residence nil rate band (RNRB) is a separate additional threshold of up to £175,000 (2026/27) for qualifying residential property passed to direct descendants. It is also transferable between spouses on the same basis as the NRB. If the first spouse to die did not use their RNRB (for example, they had no property or left everything to their spouse), 100% of the RNRB can be transferred. On the second death, the surviving spouse can have: their own NRB (£325,000) + transferred NRB (up to £325,000) + their own RNRB (£175,000) + transferred RNRB (up to £175,000) = up to £1,000,000 before IHT. The RNRB is tapered at £1 for every £2 above a £2 million net estate — so estates over £2.35 million lose the RNRB entirely.
What happens to the transferable nil rate band if the first spouse made gifts?
Gifts made by the first spouse that are not exempt (i.e. not covered by the spouse exemption, annual exemption, or other reliefs) use up part of the NRB on first death and reduce the percentage transferable. Example: if the first spouse gave £100,000 to children 3 years before death (a failed PET, as they died within 7 years), the NRB is reduced by £100,000, and only 69.2% of the NRB (£225,000 ÷ £325,000) is available to transfer. Careful lifetime gift records are essential so executors can accurately calculate the NRB used and the percentage available to transfer.
Plan your estate to use every allowance
The transferable NRB can save your estate tens of thousands in IHT — but only if your will is structured correctly and your executor knows how to claim it. WillSafe’s Executor Guide covers the full IHT return process.
Get the Essentials Bundle →Related guides
- Nil rate band UK — the basics
- Residence nil rate band — qualifying property
- Inheritance tax spouse exemption
- Nil rate band discretionary trust — is it still needed?
- IHT thresholds 2026 — full breakdown