Transferable Nil-Rate Band for Couples

Yes — if you are married or in a civil partnership, the partner who dies first can pass their unused nil-rate band to the survivor, and in most cases their unused residence nil-rate band too. In the right circumstances this means a couple can pass on up to £1 million free of inheritance tax (IHT) on the second death. The key point to remember is that the transfer is not automatic: it must be claimed by the personal representatives of the second estate, and it works as a percentage uplift rather than a fixed cash figure.

The short answer

Every individual has a nil-rate band of £325,000 — the amount of an estate that is taxed at 0% before IHT at 40% applies. When the first spouse or civil partner dies, anything they leave to the survivor is exempt under the spouse exemption, so it often uses none of their nil-rate band. The unused proportion can then be transferred to the survivor and added to their own band when they die. Because most couples leave everything to each other, the survivor frequently ends up with two full nil-rate bands — £650,000 — plus, where a home is involved, two residence nil-rate bands on top.

The rules apply in England and Wales and have been in place since October 2007, but crucially they reach back further than that: it does not matter when the first spouse died. For more on the basic allowance, see our Nil-Rate Band Explained guide.

How the transfer works

The mechanism is based on percentages, not pounds. On the first death, HMRC effectively asks: what proportion of that person's nil-rate band was not used? That unused percentage is then applied to the nil-rate band in force at the date of the second death.

An example makes this clear. Suppose a husband died in 2010 leaving his entire estate to his wife. Because spouse-to-spouse transfers are exempt, none of his nil-rate band was used — 100% is unused. When the wife dies in 2026, her estate gets her own £325,000 plus 100% of the current band (another £325,000), giving a combined nil-rate band of £650,000.

If instead the husband had left, say, £162,500 to his children (half of the then-current band) and the rest to his wife, only 50% of his band would remain. The wife's estate would receive an uplift of 50% of £325,000 — an extra £162,500 — for a total band of £487,500. The percentage approach means the survivor benefits from any later increases in the nil-rate band, although the band is currently frozen at £325,000 until April 2030.

The maximum uplift from predeceased spouses is one full additional band — 100%. Someone widowed more than once can combine unused percentages from each former spouse, but the total transferred can never exceed one extra nil-rate band.

The residence nil-rate band transfers too

Since April 2017 there has also been a residence nil-rate band (RNRB) of up to £175,000, available when a qualifying residence passes to direct descendants such as children or grandchildren. This allowance is transferable between spouses and civil partners in the same percentage way as the main band — and, helpfully, the transfer is available even if the first spouse died before the RNRB existed, because their "used" RNRB on death is simply treated as nil.

There is an important caveat. The RNRB is tapered by £1 for every £2 by which the estate exceeds £2 million, so a large estate may lose some or all of it (it is fully lost at around £2.35m where a full RNRB applies). The taper is assessed on the estate of the person who is dying, so careful planning is needed for high-value estates. Our Residence Nil-Rate Band Explained guide covers the qualifying conditions, the downsizing addition, and the taper in detail.

How couples reach the £1 million figure

The widely quoted "£1 million" comes from stacking all four allowances on the second death:

• Survivor's own nil-rate band: £325,000
• Transferred nil-rate band: £325,000
• Survivor's own residence nil-rate band: £175,000
• Transferred residence nil-rate band: £175,000

That totals £1,000,000. But it only works in specific circumstances: the couple must be married or in a civil partnership, a qualifying home must pass to direct descendants, the estate must be below the £2 million taper threshold, and both full bands must be available for transfer. Couples without children, unmarried partners, or those with estates over £2 million will not reach the full figure. For the bigger picture, see our Inheritance Tax UK: Complete Guide and our practical How to Reduce Inheritance Tax guide.

How to claim on the second death

This is where estates most often go wrong. The transfer must be claimed by the personal representatives of the second estate — it is not granted automatically. The transferable nil-rate band is claimed on form IHT402, and the transferable residence nil-rate band on form IHT436, submitted alongside the main IHT account.

There is a strict deadline: the claim must be made within two years of the end of the month in which the second death occurs (or, if later, three months after the personal representatives first act). HMRC has discretion to accept late claims but you should not rely on it.

To support the claim, the executors will need evidence about the first death, including a copy of the death certificate, the marriage or civil partnership certificate, the will (if any) and details of the grant of probate, and figures showing how much of the first person's nil-rate band was used. This is why it is so important to keep the paperwork from the first death safe — sometimes for many years. Reconstructing a 1990s estate without records is difficult and can jeopardise a valuable claim.

Common pitfalls and edge cases

Old nil-rate band discretionary trust wills. Before 2007 it was common for couples to use a will trust to "bank" the first spouse's nil-rate band, because transfer was not then possible. Since the band became transferable, many of these trusts are unnecessary and can complicate the estate. If your will still contains one, it is worth reviewing — though in some cases such a trust is still useful for asset protection. See Discretionary Trusts Explained for how they work.

Lifetime gifts and chargeable transfers. Gifts made in the seven years before the first death, or lifetime transfers into certain trusts, can use up part of the first nil-rate band and reduce the percentage available to transfer. Our Gifts and Inheritance Tax guide explains the seven-year rule and taper relief on the tax due.

Unmarried couples. The transfer is available only to married couples and civil partners. Cohabitees cannot inherit each other's bands and do not benefit from the spouse exemption — a frequent and expensive trap.

Multiple marriages. Unused percentages from more than one former spouse can be combined, but the cap of one extra band of each type still applies.

When to get professional advice

The transferable nil-rate band is one of the most generous reliefs in the IHT system, but the interaction of the main band, the residence band, the £2 million taper, lifetime gifts and any trusts can be genuinely complex. Estates near the taper threshold, blended families, business or agricultural assets, and old trust-based wills all warrant tailored advice — particularly given that, from 6 April 2026, 100% Business Property Relief and Agricultural Property Relief are limited to the first £1 million of combined qualifying property per person, with value above that getting 50% relief. A qualified, regulated estate planner can review your wills, confirm which allowances will be available, and make sure the second estate's executors know exactly what to claim. Given the sums involved, professional advice is strongly recommended where any of these factors apply.