The downsizing addition to the residence nil rate band lets an estate keep this inheritance tax allowance even after someone sells or downsizes their home. If a person sold, gave away or moved to a less valuable property on or after 8 July 2015, and direct descendants inherit at least an equivalent value, the residence nil rate band that would otherwise be lost can be reinstated.
This matters because the residence nil rate band, worth up to £175,000 per person, normally depends on a home passing to children or grandchildren (gov.uk, as at August 2026, subject to change). Many people in later life sell up, downsize or move into care. Without a specific rule, that decision would quietly forfeit a large allowance. The downsizing addition is that rule.
What is the downsizing addition to the residence nil rate band?
The downsizing addition is a rule that restores residence nil rate band an estate would otherwise lose because the person sold or downsized their home before death. Introduced by the Finance Act 2016 and in force from 6 April 2017, it treats the lost home relief as still available and applies it against other assets left to direct descendants.
The residence nil rate band sits on top of the standard nil rate band of £325,000. Together they can shelter up to £500,000 for a single person, or up to £1,000,000 for a married couple or civil partners where unused allowances transfer to the survivor and a home passes to descendants (gov.uk, as at August 2026, subject to change).
The addition does not hand you cash or a home. It restores the allowance, so more of the estate falls below the point where inheritance tax at 40% starts. It only helps if there are other assets, such as savings, shares or investments, passing to the same qualifying people.
Do you still get the residence nil rate band if you sold or downsized your home?
In many cases, yes. If you sold your home, gave it away or moved somewhere less valuable on or after 8 July 2015, your estate can usually still claim residence nil rate band through the downsizing addition, provided direct descendants inherit at least an equivalent value and the estate is within the taper threshold.
All of these conditions generally need to apply for a claim to succeed:
- The home was sold, given away or replaced with a less valuable one on or after 8 July 2015. Disposals before that date do not count.
- The former home would have qualified for the residence nil rate band if it had been kept until death. The person must have lived in it at some point.
- At least some of the estate passes to direct descendants: children, grandchildren, step, adopted or foster children, and their spouses.
- The estate is within the £2,000,000 taper threshold. Above that, the residence nil rate band is withdrawn by £1 for every £2 of value, which reduces the addition too (gov.uk, as at August 2026, subject to change).
Selling completely and renting, or moving into residential care, does not rule you out. A person who owns no home at death can still pass on the full residence nil rate band, as long as other assets of equivalent value go to their descendants.
How is the downsizing addition calculated?
HMRC compares the residence nil rate band the former home could have used against the band the current home (or no home) can use, then tops up the difference. The result is capped at the maximum residence nil rate band for the year and at the value actually passing to direct descendants.
HMRC sets out a five step method. The value used for the former home is its value at the date it was sold or given away, not today's price:
- Find the residence nil rate band available when you disposed of the former home, including any transferred from a late spouse or civil partner.
- Divide the former home's value at disposal by that figure, expressed as a percentage and capped at 100%.
- Divide the current home's value at death by the residence nil rate band available at death, again capped at 100%. If no home is owned at death, this is 0%.
- Subtract the step 3 percentage from the step 2 percentage. This is the proportion of band that was lost.
- Multiply the residence nil rate band available at death by that lost percentage. The answer is the downsizing addition (gov.uk, as at August 2026, subject to change).
The two worked examples below show how this plays out. Both assume a single person, no transferred band, an estate under £2,000,000, and enough other assets left to direct descendants. Figures use the £175,000 maximum band frozen for these years.
| Scenario | Former home value at disposal | Home owned at death | Band on current home | Downsizing addition | Total residence nil rate band |
|---|---|---|---|---|---|
| Sold up, now renting or in care | £400,000 | None | £0 | £175,000 | £175,000 |
| Downsized to a smaller flat | £500,000 | £150,000 flat to daughter | £150,000 | £25,000 | £175,000 |
Illustrations only, based on gov.uk, as at August 2026, subject to change. In the first row the former home covered 100% of the band and no home remains, so all £175,000 is restored. In the second, the flat covers most of the band and the addition tops up the small remainder.
How do you claim the downsizing addition?
The downsizing addition is not automatic. The personal representative of the estate has to claim it after death, alongside the standard residence nil rate band, using HMRC's form IHT435 and within a strict time limit. If no one claims it, the lost allowance is simply forgone, so a possible claim is worth identifying early when administering the estate.
The usual steps are:
- Work out the lost band using the five step method above, for the disposal that gives the best result if there was more than one.
- Complete form IHT435, the claim for residence nil rate band, recording the downsizing details and values.
- Add form IHT436 if you are also transferring a late spouse's or civil partner's unused residence nil rate band.
- Submit these with the IHT400 account within two years of the end of the month in which the person died. HMRC can extend this in limited circumstances (gov.uk, as at August 2026, subject to change).
What people get wrong about the downsizing addition
The most costly mistakes come from assuming the addition works automatically, or that it only helps if you buy another home. In practice it is missed, underclaimed or wrongly ruled out more often than it is denied, and the two year deadline is unforgiving once passed.
From what we see in practice, these are the points that trip families up:
- You do not have to buy another home. Selling entirely and renting, or moving into care, still qualifies. Owning no home at death is not a barrier.
- You still need assets passing to descendants. The addition applies against other assets, but only if those assets actually go to children or grandchildren. Leaving everything to a sibling or friend loses it.
- The former home is valued at the date of disposal. It is the sale value or market value when you moved, not the price it would fetch now.
- It must be claimed. No one at HMRC applies it for you. A personal representative has to claim within two years of the end of the month of death.
- Only one disposal counts. If someone moved several times, the representative picks the single disposal that gives the largest addition.
Do the 2025 Budget changes affect the downsizing addition?
The downsizing rules themselves are unchanged, but the surrounding thresholds are frozen for longer. At the Budget on 26 November 2025 the nil rate band, residence nil rate band and taper threshold were extended to remain fixed until 5 April 2031, which pulls more downsizers' estates into inheritance tax over time.
The standard nil rate band stays at £325,000 and the residence nil rate band at up to £175,000 until the end of the 2030 to 2031 tax year (gov.uk, as at August 2026, subject to change). As house prices and savings rise against frozen allowances, claiming every available relief, including the downsizing addition, matters more.
Two wider reforms also change the overall picture. From 6 April 2026, agricultural and business property relief gives 100% relief on the first £2,500,000 of qualifying assets per person and 50% above, transferable to £5,000,000 per couple. From 6 April 2027, unused pension funds are expected to fall within the inheritance tax net (gov.uk, as at August 2026, subject to change). Both can push an estate towards the £2,000,000 taper threshold, which erodes the residence nil rate band and any downsizing addition. Reviewing your inheritance tax position as part of wider estate planning can help keep the allowance intact.
Frequently asked questions
These are the questions families most often ask about the downsizing addition and the residence nil rate band. In short, selling a home or moving into care on or after 8 July 2015 rarely loses the allowance, the personal representative usually has to claim it within two years of the end of the month of death, and equivalent value still needs to pass to direct descendants for the addition to apply.
Does the downsizing addition apply if I sold my home to move into care?
In many cases, yes. Selling a home to move into residential care is treated the same as any other disposal on or after 8 July 2015. Your estate can still claim the residence nil rate band through the downsizing addition, as long as equivalent value passes to direct descendants and the estate is within the taper threshold.
What date does the downsizing addition start from?
The disposal must have happened on or after 8 July 2015. Homes sold, given away or downsized before that date do not qualify for the downsizing addition, even though the residence nil rate band itself only began on 6 April 2017 (gov.uk, as at August 2026, subject to change).
How long do you have to claim the downsizing addition?
A personal representative must claim within two years of the end of the month in which the person died, using form IHT435. HMRC can allow longer in limited circumstances, but the deadline is otherwise firm, so it is worth identifying a possible claim early in administering the estate.
What happens if the sale price was lower than the probate value?
For the downsizing calculation, the former home is valued at its market value on the date it was sold or given away, not a later probate value. If a sale was at arm's length, the sale proceeds usually reflect that market value. Unusual sales below market value may need a separate valuation.
Do you pay capital gains tax when you downsize your main home?
Usually no. Selling your only or main home is generally covered by private residence relief, so no capital gains tax arises on it. Second homes, buy to let property or land can be different. This is separate from inheritance tax and the downsizing addition (gov.uk, as at August 2026, subject to change).