A probate property valuation is the open market value of a house or flat at the date of death: the price it would reasonably be expected to fetch if sold between a willing buyer and a willing seller on the day the owner died (HMRC Inheritance Tax Manual, IHTM09703, s.160 IHTA 1984, as at August 2026, subject to change). For most estates a written estate agent appraisal is enough; where inheritance tax may be due, a RICS "Red Book" surveyor's report is the figure HMRC is least likely to challenge.
What is a probate property valuation?
A probate property valuation is the figure a personal representative records for a house, flat or land as part of valuing the whole estate. The legal standard is open market value at the date of death, defined by HMRC as the price the asset "might reasonably be expected to fetch if sold in the open market" at that time (HMRC Inheritance Tax Manual, IHTM09703, as at August 2026, subject to change).
Two things follow. The value is fixed on the day of death, so later movements in the market do not change it. And it assumes a normal sale, which is why an insurance rebuild cost, a mortgage lender's figure, a council tax band, or a quick "we buy any house" cash offer are not the right measure. The property value feeds into the estate total, which decides both the probate route and any inheritance tax. If you are new to the process, our guide to what probate is and how it works shows where valuation fits in.
Probate value versus market value: what is the difference?
Probate value and market value often land on a similar figure, but they answer different questions. A probate value is a considered assessment as at the date of death that must stand up to HMRC scrutiny. A market appraisal is an estate agent's view of what a property might sell for now, sometimes pitched high to win the instruction.
| Feature | Probate value | Market appraisal |
|---|---|---|
| Date it reflects | Open market value at the date of death | Today's likely selling price |
| Purpose | Inheritance tax and the estate total | Setting an asking price to sell |
| Audience | HMRC and the Probate Registry | The seller |
| Tendency | Evidence-based and defensible | Can be optimistic to win the listing |
The distinction matters because an inflated asking-price appraisal used as the probate figure can raise inheritance tax needlessly, while a figure set artificially low can store up a larger capital gains tax bill later. Both risks are covered below.
Who should value the property: a RICS surveyor or an estate agent?
Either can produce a probate figure, and both are used. The right choice depends on the estate's size and whether inheritance tax is in play. HMRC recommends using a professional so the figures are as accurate as possible (gov.uk, valuing the estate of someone who has died, as at August 2026, subject to change).
| RICS Red Book valuation | Estate agent appraisal | |
|---|---|---|
| Typical cost | Around £300 to £800, higher in London and the South East (market guidance, as at August 2026, subject to change) | Usually free |
| Weight with HMRC | Strongest; prepared to a recognised standard, dated at death, with comparables | Accepted for smaller, clearly non-taxable estates; weaker if queried |
| Best suited to | Estates near or above the tax thresholds, unusual or high-value property, or where a challenge is likely | Straightforward homes in estates well below the thresholds |
| Backed by | A chartered surveyor with professional indemnity insurance | Local sales knowledge, no formal liability |
A practical rule: if the estate is comfortably below the available nil-rate bands and no tax is at stake, one or more written estate agent appraisals may be enough. If tax may be due, or the figure is finely balanced, a RICS report is usually worth the cost. Our inheritance tax guide explains how the thresholds combine.
How to value a house for probate, step by step
To value a house for probate, obtain the open market value as at the date of death in writing, from an estate agent for a straightforward estate or a RICS surveyor where inheritance tax may be due. Keep the report, the comparables and photographs of condition, then report the figure to HMRC as part of the estate. The five steps below set out the sequence.
- Decide the route. Choose an estate agent appraisal or a RICS Red Book valuation based on the estate's likely tax position and the property's complexity.
- Get the figure as at the date of death. Ask for the open market value on the day the owner died, in writing. A surveyor can prepare a retrospective valuation dated to that day if time has passed.
- Gather at least one written valuation. For borderline estates, two or three appraisals, or a single RICS report, give a defensible figure rather than a guess.
- Keep the evidence. Retain the report, the comparables it relied on, and photographs of condition. HMRC can look back at valuations for several years.
- Report it to HMRC. Many estates are "excepted" and report values through the probate application; where a full account is needed, land and buildings go on form IHT405 attached to form IHT400 (gov.uk, form IHT405, as at August 2026, subject to change).
If the estate later sells the property, the sale price is a useful cross-check but does not replace the date-of-death figure. Our guide to valuing land for probate covers gardens, paddocks and agricultural parcels, which follow the same open market rule with extra factors.
Range of possible penalties on extra tax from an inaccurate valuation, from careless to deliberate and concealed (gov.uk, penalties, as at August 2026, subject to change).
What people get wrong: the too-low trap and the tax link
The most common mistake is treating a probate valuation as a figure to minimise. Valuing too low to save inheritance tax can create a larger capital gains tax bill when the property is later sold, because the probate value becomes the base cost. A second error is relying on an unofficial "15% margin" that HMRC does not publish. An honest, well-evidenced open market value protects against both.
Valuing too low to cut inheritance tax can create a bigger capital gains tax bill. The probate value becomes the estate's base cost for capital gains tax. If the property is later sold for more than that figure, the gain is taxed. For 2026/27 the capital gains annual exempt amount is £3,000 and the higher rate on residential property gains is 24% (gov.uk, Capital Gains Tax rates, as at August 2026, subject to change). Shaving the probate figure to save 40% inheritance tax can therefore hand back tax at 24% on the way out, and on a spouse-exempt or below-threshold estate it saves no inheritance tax at all while raising the eventual gain.
There is no official HMRC tolerance. Guides often quote a "15% margin" that HMRC supposedly ignores. HMRC publishes no such safe band. It may not query small differences, but a personal representative who relies on an unpublished margin has no protection if the figure is challenged. The safeguard is a reasonable, well-evidenced valuation, not a guessed cushion.
What happens if HMRC disagrees with the valuation?
HMRC can refer a property valuation to the Valuation Office Agency, whose District Valuer is a chartered surveyor acting for HMRC (gov.uk, Valuation Office Agency, as at August 2026, subject to change). Higher-value homes, unusual properties and figures that look low are the most likely to be reviewed. If the figure is found too low, extra tax, interest and a penalty can follow, though a properly evidenced valuation is usually accepted.
If the District Valuer considers the figure too low, the personal representative may be asked to justify it, and extra tax plus interest can follow. Penalties depend on behaviour: up to 30% of the additional tax where reasonable care was not taken, up to 70% for a deliberate under-valuation, and up to 100% where it is deliberate and concealed (gov.uk, penalties, as at August 2026, subject to change). In practice, a personal representative who obtained a proper professional valuation and disclosed it honestly is unlikely to face a penalty even if HMRC later negotiates a higher figure. A clear RICS valuation, dated at the date of death and backed by comparables, is the strongest response to a query.