Answers · UK 2025/26
How is the unused inheritance tax nil rate band transferred between spouses?
When a spouse or civil partner dies and leaves everything to the surviving spouse, no IHT is payable due to the spousal exemption. This means the entire Nil Rate Band of £325,000 is unused and can be transferred to the survivor, doubling their combined NRB to £650,000 -- plus up to £350,000 RNRB, giving a potential £1,000,000 tax-free total.
Full answer
The transferable Nil Rate Band (TNRB) allows a surviving spouse or civil partner to inherit any portion of the deceased partner's unused Nil Rate Band (NRB), effectively increasing the survivor's IHT allowance. **The Nil Rate Band in 2026/27** - Each individual's NRB: **£325,000** (frozen until at least April 2028) - Maximum NRB per surviving spouse: **£650,000** (if first spouse's NRB fully unused) **How the transfer works** The NRB is not automatically transferred on first death -- the personal representatives of the surviving spouse's estate must make a claim to HMRC after the second death, providing evidence of the first spouse's estate and the NRB used at that time. **The transfer percentage, not the cash amount** HMRC transfers the percentage of the NRB unused, not the cash value. This matters because the NRB may have changed between the two deaths. **Worked Example** - First spouse dies in 2010 when NRB was £325,000 - All assets passed to surviving spouse -- NRB 100% unused - Second spouse dies in 2026/27 when NRB is still £325,000 - TNRB transferred: 100% of £325,000 = £325,000 - Total NRB available: £325,000 + £325,000 = **£650,000** *If the first spouse had used 50% of the NRB (e.g., £162,500 left to children):* - Unused percentage: 50% - TNRB: 50% x £325,000 = £162,500 - Survivor's total NRB: £487,500 **Combining with the Residence Nil Rate Band** The Residence Nil Rate Band (RNRB) of £175,000 per person is also transferable between spouses. If both NRBs and RNRBs are fully transferred: | Allowance | Amount | |---|---| | Survivor's own NRB | £325,000 | | Transferred NRB | £325,000 | | Survivor's own RNRB | £175,000 | | Transferred RNRB | £175,000 | | **Total** | **£1,000,000** | **Claiming the transfer** Claim using HMRC form IHT402 (for the NRB) and IHT436 (for the RNRB), submitted with the probate application after the second death. Keep records of the first spouse's estate including the IHT return or confirmation that no IHT was due. **No time limit** There is no time limit to claim the TNRB -- it can be claimed decades after the first death, provided the evidence is available.
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This answer is informational only and does not constitute financial, tax or legal advice. Figures are for the 2025/26 UK tax year. See our methodology and sources.