Most people who have heard of inheritance tax have heard one number: £325,000. Rather fewer have heard the second one, and of those who have, a good proportion assume it applies to them automatically. It does not. The residence nil-rate band is the most conditional allowance in the inheritance tax system, and the conditions are where the money is won and lost.
This is what it is, who qualifies, and the four ways people find out too late that they do not.
Two allowances, doing different jobs
The nil-rate band is £325,000. It belongs to every estate, applies to any kind of asset, and asks nothing of you. Above it, inheritance tax is charged at 40%.
The residence nil-rate band is up to £175,000 more. It is attached to a home, and it is attached to who inherits that home. It sits on top of the nil-rate band rather than replacing it, so an estate that qualifies for both has up to £500,000 before tax — and a couple who each qualify, and where the first to die leaves everything to the survivor, can reach £1 million on the second death.
That million-pound figure gets quoted constantly, usually without the conditions attached to the second half of it. Both figures are also fixed until the end of the 2030 to 2031 tax year under legislation introduced in Finance Bill 2025-26. Frozen thresholds and rising house prices pull more estates into charge every year without any rate ever changing.
"Direct descendant" is narrower than "family"
This is the first place estates fall out. HMRC's guidance lists who qualifies, and the list is specific:
- a child, grandchild or other lineal descendant
- a spouse or civil partner of a lineal descendant, including their widow, widower or surviving civil partner
- a child who is, or was at any time, a step-child of the deceased
- an adopted child
- a child fostered at any time by the deceased
- a child for whom the deceased was appointed guardian or special guardian while the child was under 18
Read what is absent. A sibling is not a direct descendant. Nor is a niece, a nephew, a cousin, or a friend. Someone who never had children and leaves their home to a much-loved nephew gets the £325,000 nil-rate band and nothing else — no residence allowance at all, on exactly the same house.
The inclusion of step-children, adopted children, fostered children and children under guardianship is generous, and it is the part most often missed in the other direction. A step-child counts whether or not they were ever formally adopted.
The home has to be one you lived in
The second condition is about the property. HMRC states that the person who died must have owned and lived in the property at some time. A property owned purely as an investment and never inhabited — the classic buy-to-let — does not qualify, regardless of its value or how long it was held.
It does not have to be the home they died in. A house lived in for years and later let out can still qualify. But there must have been a period of actual residence, not merely ownership.
And only one home can qualify. An estate holding three properties does not get three allowances; the personal representatives nominate one.
The taper, which is where large estates lose it
The third condition is size, and it works differently from the others because it is gradual rather than binary.
The residence nil-rate band reduces by £1 for every £2 that the estate is worth more than the £2 million taper threshold. The threshold is frozen alongside the allowances themselves.
The arithmetic is worth doing once, because it produces a number people do not expect. A single person's £175,000 allowance is removed entirely by £350,000 of excess — two pounds of estate for every pound of allowance. So:
- At an estate of £2 million, the full £175,000 is available.
- At £2.175 million, half of it has gone.
- At £2.35 million, it is gone completely.
Where a spouse's unused allowance has been transferred, the combined £350,000 needs £700,000 of excess to disappear, so it is extinguished at an estate of £2.7 million.
Note carefully what this means. Between £2 million and £2.35 million, each additional pound in the estate carries not only its own 40% but the loss of fifty pence of allowance, which is itself taxed at 40%. The effective marginal rate over that band is considerably higher than 40%. This is the strongest argument in the whole system for taking estate value seriously before death rather than after it.
What a surviving spouse gets
Transfers between spouses and civil partners are exempt from inheritance tax, so nothing is usually paid on the first death. The allowances are not lost in the meantime: any unused residence nil-rate band can be transferred to the surviving spouse or civil partner, exactly as the ordinary nil-rate band can.
That is the mechanism behind the combined figures. It is claimed on the second death, by the personal representatives of the second estate, and it requires the paperwork from the first death — which is a practical argument for keeping estate records long after everyone has stopped thinking about them.
If the house was already sold
People move into care, or downsize, or sell up entirely, and the obvious fear is that the allowance dies with the house. It does not automatically.
A downsizing addition can preserve the allowance where the former home was sold, given away, or replaced with a less valuable one on or after 8 July 2015, provided the estate still passes to direct descendants. The date is a hard cut-off: disposals before it do not attract the addition.
This is one of the more involved corners of the rules and the calculation depends on the value of the property disposed of and what the estate is worth afterwards. If it applies to you it is worth proper advice rather than a rule of thumb.
Where life insurance quietly changes the answer
Here is the connection that catches people, and it is the reason this article sits alongside the others on this site.
A life insurance policy that is not written in trust generally forms part of your estate. For most estates that matters only for the 40% charge on the payout itself. But for an estate near £2 million, the payout does something worse: it adds to the figure the taper is measured against.
A £400,000 policy falling into a £1.9 million estate does not simply bring £400,000 into charge. It takes the estate to £2.3 million, which strips away £150,000 of residence nil-rate band that the family would otherwise have had. The policy bought to make things easier has made the tax position measurably harder.
Writing the policy in trust keeps it out of the estate, so it is neither taxed nor counted for the taper. It is usually free and usually done at application. If the estate is anywhere near the threshold, this is not a marginal piece of admin.
The related question — what happens to a payout when there is no will at all — is covered in the guide to who inherits life insurance under the intestacy rules.
What to actually check
- Are there direct descendants? If not, the residence allowance is almost certainly unavailable, and planning should start from £325,000, not £500,000.
- Was the property ever lived in? Investment property alone does not qualify.
- What is the estate actually worth, including any life insurance not in trust, and any pension death benefits? If the answer is near £2 million, the taper is the first thing to model.
- Is there an unused allowance from a first death? It does not claim itself.
- Was a former home sold on or after 8 July 2015? If so, ask about the downsizing addition.
This article explains how the allowance works. It is not advice on your estate, and inheritance tax planning is one of the areas where the gap between the general rule and a particular set of facts is widest. A solicitor or a chartered tax adviser is the right next step if the numbers here are close to yours.
Sources
- GOV.UK — Work out and apply the residence nil rate band for Inheritance Tax (opens in a new tab)
- GOV.UK — Check if an estate qualifies for the Inheritance Tax residence nil rate band (opens in a new tab)
- GOV.UK — Inheritance Tax nil-rate band and residence nil-rate band thresholds from 6 April 2026 to 5 April 2028 (opens in a new tab)
- HMRC Inheritance Tax Manual IHTM46023 — the 'taper threshold' (opens in a new tab)
- GOV.UK — Inheritance Tax thresholds (opens in a new tab)
This article is general information for a United Kingdom audience and describes the inheritance tax rules of England and Wales. Scotland and Northern Ireland differ in aspects of succession law. It is not financial, tax or legal advice. Inheritance tax rules and thresholds change, and the position of any particular estate depends on its assets, the family circumstances and the terms of any trust. Take advice from a solicitor or a chartered tax adviser before relying on any of this. Last reviewed 12 September 2026.
