Downsizing and the £175,000 allowance your executors must claim

You sell the family house, move somewhere smaller near the sea, and put the difference in the bank. Sensible. But a question follows you home: does the estate lose the extra Inheritance Tax allowance that was attached to that house?

The short answer is no — not automatically. There is a rule designed for exactly this moment, and it has been on the statute book since 2015. It is called the downsizing addition, and it is one of the few parts of Inheritance Tax that actively works in a family’s favour. It does, however, depend on someone making a claim after a death, in a specific window, with the paperwork to hand.

What the rule actually is

Alongside the nil-rate band of £325,000 — frozen until 2030 — there is the residence nil-rate band of £175,000. It applies where a home, or a share of one, passes on death to direct descendants: children, stepchildren, adopted and foster children, grandchildren and so on. Together, a married couple or civil partners can pass on up to £1m before Inheritance Tax, where both allowances are available in full. The residence nil-rate band tapers away above a £2m estate, at £1 for every £2 over.

The obvious problem is that the allowance is tied to owning a home. Sell it, give it away, or move somewhere less valuable, and the relief looks as though it evaporates. Parliament saw that and built in the downsizing addition. In plain terms: if a former home was disposed of on or after 8 July 2015, and the estate would have qualified for the residence nil-rate band had the person kept it, the estate can claim an addition that replaces the allowance lost on the move.

The conditions, in plain English

• The sale, gift or move to a less valuable home happened on or after 8 July 2015 and before death.
• The former home would have qualified for the residence nil-rate band if it had still been owned at death — broadly, it was the person’s residence at some point.
• Direct descendants inherit at least some of the estate. Importantly, they do not have to inherit a house. Cash, shares, or a share of the business will do.
• A claim is made by the personal representatives — the executors, in most cases.

The addition works by measuring the allowance that was lost on the disposal, comparing the value of the former home against the maximum residence nil-rate band available at the time of the move. Where the disposal happened between 8 July 2015 and 5 April 2017, the maximum is treated as £100,000. The addition can never push the total relief above the residence nil-rate band that would otherwise have been available.

A worked example

Take a Worthing couple — call them Margaret and Alan, invented purely as an illustration. They sell the four-bedroom family house in 2021 and buy a two-bedroom flat near the seafront. The difference goes partly into helping their daughter, partly into a share portfolio, partly into the current account.

Alan dies first. Everything passes to Margaret, so no Inheritance Tax arises and his unused allowances carry across. Margaret dies some years later. Her estate holds the flat, worth considerably less than the old house, plus a healthy share portfolio. Their daughter inherits everything.

Without the downsizing rule, the residence nil-rate band available to Margaret’s estate would be limited by the modest value of the flat. With the downsizing addition claimed, the estate can restore the allowance lost when the family house was sold — up to the full £175,000, and up to £350,000 across the two of them, because their daughter inherits other assets from the estate. The tax saved runs to tens of thousands of pounds. Same family, same assets, entirely different tax bill — decided by whether someone made a claim.

The traps

It is not automatic. HMRC does not apply the downsizing addition on the estate’s behalf. The personal representatives must claim it as part of the Inheritance Tax return, and the deadline is two years from the end of the month in which the person died. HMRC can extend that in some circumstances, but nobody should plan on the extension.

Only one disposal counts. If there were several moves after 8 July 2015, only one former home can be nominated for the calculation. Where a family has moved twice, the choice of which sale to nominate can be worth real money — and it can only be made well if the figures for each move still exist.

The paperwork tends to disappear. The calculation needs the value of the former home at the date of disposal and the date of the move. Completion statements, the sale contract, the estate agent’s figures — these are the evidence. Ten years later, after a house move and a change of solicitor, they are exactly the documents nobody can find. Keeping one folder, physical or digital, with the completion statement in it, is the single most useful thing a downsizer can do.

The £2m taper still applies. A large estate can taper the residence nil-rate band away entirely, downsizing addition or not. Where a business or a property portfolio pushes the estate over £2m, the planning has to happen during lifetime, not afterwards.

Business owners and landlords, take note. From April 2026 the combined cap on Business Relief and Agricultural Property Relief is £2.5m for a couple, with relief at 50% above it. From 6 April 2027 unused pensions come inside the estate for Inheritance Tax. Both changes push more estates towards, and over, the £2m taper threshold — which makes the residence allowance more fragile precisely when families are relying on it.

Where couples gain most

The downsizing addition follows the same logic as the rest of the residence nil-rate band: allowances unused on a first death can be transferred to the survivor. A widow or widower can therefore end up with their own £175,000 and a transferred £175,000, restored through the downsizing rules even though the family home was sold years earlier. Set against the two nil-rate bands of £325,000, that is where the widely quoted £1m for a couple comes from.

It is worth being clear about what the rule does not require. It does not require the money from the sale to be traceable, or spent in any particular way. It does not require the survivor to buy another property. It does not require the children to inherit bricks and mortar. What it requires is a qualifying former home, a disposal on or after 8 July 2015, direct descendants inheriting something, and a claim.

Moving into care, or in with family

Downsizing is the headline, but the rule is broader than the word suggests. Selling the house to fund a care home place counts as a disposal. So does selling up and moving in with a son or daughter. So does giving the house away outright, though a gift of the home brings its own complications — gifts with reservation of benefit, and the seven-year rule for lifetime gifts — which need to be looked at on their own terms rather than assumed away.

A family that has been through a period of illness rarely has the sale paperwork filed neatly. That is precisely the situation the two-year claim window was not designed for, and precisely where the relief gets lost.

How the claim is actually made

There is nothing to tell HMRC at the time of the move. No form, no registration, no notification. The whole of the downsizing addition is dealt with after death, on the Inheritance Tax return, where the personal representatives claim the residence nil-rate band and the downsizing addition together and nominate the former home being taken into account.

That design has one consequence worth sitting with. The person who knows the facts — which house, what it sold for, on what date, and which of two moves is the better one to nominate — is the person who has died. Everything afterwards depends on what they left behind for their executors to find.

What to do

• If you have sold, gifted or downsized from a home since 8 July 2015, find the completion statement and put it somewhere your executors will look.
• Note the date of the disposal and what the property fetched. One side of A4 is enough.
• Where there has been more than one move, keep the figures for each — the nomination is a choice, and choices need evidence.
• Tell your executors the downsizing addition exists. It is the claim most often missed.
• If the estate is near or above £2m, look at the taper and at the timing of any lifetime gifting well before the Autumn Budget on 28 October 2026.

A short close

The downsizing addition is a rare thing: a relief that rewards families who have already done the sensible thing. Preserving it takes nothing; overlooking it is expensive. The work is small — a date, a figure, a completion statement, and executors who know to ask.

If you have downsized, or expect to, a 30-minute Discovery Call will tell you where you stand and what your executors will need. The fee is £30, credited against our fees when you instruct us.