How to Value a Property for Probate or Inheritance Tax

Valuing a property after someone has died is a different exercise to valuing one for a sale. The number you need isn't "what would a buyer pay today" in the ordinary sense — it's a specific, defensible figure for a specific date, one that HMRC can and does check. See our guide on how UK property valuations work for the comparable-sales method behind any starting estimate.

What HMRC actually wants: open market value at the date of death

For probate and Inheritance Tax purposes, a property must be valued at its "open market value" as at the date the person died — the price it would have achieved if sold on the open market on that specific date, between a willing buyer and a willing seller, neither under pressure to transact. This figure feeds into the total value of the estate, which determines whether Inheritance Tax is due, and how much.

Why this matters more than people expect

Two mistakes are common, in opposite directions. Undervaluing the property understates the estate and, if HMRC's District Valuer later assesses it higher (they can, and do, particularly check probate valuations against subsequent sale prices), the estate can face additional tax, interest, and in some cases penalties. Overvaluing it means the estate may pay more Inheritance Tax than it needed to. Neither is a paperwork formality — both have a real financial cost to the beneficiaries.

How estates actually get this valuation

Two routes are common in practice:

• Estate agent appraisals. Getting two or three local estate agents to give a written opinion of value is a widely used, low-cost approach for smaller or more straightforward estates, particularly where the total estate is clearly well under the Inheritance Tax threshold and the risk of a later challenge is low.
• A formal RICS "Red Book" valuation. A qualified RICS valuer produces a formal report specifically for probate purposes, following recognised valuation standards. This carries more weight if HMRC queries the figure, and is the more defensible choice where real tax is at stake, the property is unusual or high-value, or beneficiaries disagree on what it's worth.

See our guide on RICS surveys vs online valuations for what a formal RICS valuation actually involves and what it costs. If different estate agents give noticeably different figures, our guide on why valuation tools disagree explains why that gap is normal, not a sign one of them is wrong.

What an online tool like this one can, and can't, do here

A comparable-sales-based estimate (like this site's own) is a genuinely useful starting point — it can tell an executor roughly what to expect before commissioning anything formal, and can flag whether the estate is likely to be anywhere near the Inheritance Tax threshold at all. What it cannot do is stand in for the date-of-death valuation HMRC expects on the IHT paperwork, because it isn't a professional opinion tied to a specific date and doesn't account for the property's actual condition. Treat it as a sense-check for the executor, not the figure you submit.

If the property later sells for a different amount

It's common for a probate valuation to differ from what the property eventually sells for, sometimes because the market moved in the months it takes to administer an estate, sometimes because probate valuations are inherently a snapshot estimate. UK law includes a specific relief (loss relief on land sold by personal representatives) that can, subject to conditions and time limits, let the estate substitute a lower actual sale price for the original probate value and potentially reclaim overpaid Inheritance Tax. This is genuinely worth raising with a solicitor if the eventual sale price comes in notably below the probate figure — but the rules are specific enough that it needs proper advice, not an assumption that any drop in price automatically qualifies.

A worked example

An executor is administering an estate that includes a house. Two estate agents give informal appraisals of £410,000 and £425,000. Because the total estate value is close to the Inheritance Tax threshold and one beneficiary has queried the figure, the executor commissions a formal RICS probate valuation, which comes back at £417,500 — a more defensible, professionally documented figure to use on the IHT paperwork. Fourteen months later, after some necessary repairs and a change in local market conditions, the house actually sells for £398,000. The executor's solicitor reviews whether the loss-relief provisions apply, given the sale happened within the relevant time window and for a genuinely lower price, and where they do apply, the estate can potentially use the £398,000 figure instead and reclaim some of the Inheritance Tax already paid on the higher probate value.

Frequently asked questions

Can I use a free online valuation for probate?

You can use one to get a rough sense of the figure early on, but HMRC expects the value declared on the probate/IHT paperwork to be a genuine, defensible open market value as at the date of death. For a straightforward, clearly low-value estate that isn't near the Inheritance Tax threshold, informal estate agent appraisals are commonly accepted. Where real tax is at stake, a formal RICS valuation specifically for probate purposes is the safer route.

What if the property sells for less than the probate valuation?

UK inheritance tax law includes relief for land and property sold at a loss within a set period after death, which can allow the estate to substitute the sale price for the original probate value and potentially reclaim overpaid tax. The rules and time limits are specific, so this needs a solicitor or tax adviser, not a general assumption that it applies automatically.

Who is responsible for getting the valuation right?

The executor or personal representative administering the estate. Submitting a figure that's later found to be too low can result in HMRC's District Valuer challenging it, with additional tax, interest, and potentially penalties due — which is why executors of estates with any real value at stake commonly commission a formal valuation rather than relying on their own estimate.

Does every estate need a formal RICS valuation?

No. Many straightforward estates, particularly where the total value is clearly well under the Inheritance Tax threshold, are administered using informal estate agent appraisals without issue. A formal valuation becomes more important the closer an estate sits to the threshold, the more valuable or unusual the property, or the more likely the figure is to be scrutinised or disputed between beneficiaries.

In summary

• Probate valuation needs a specific, defensible "open market value" as at the date of death — not a general sense of current worth.
• Getting it wrong in either direction has a real cost: understating risks HMRC challenge, interest and penalties; overstating risks paying more Inheritance Tax than necessary.
• Informal estate agent appraisals suit smaller, straightforward estates; a formal RICS "Red Book" valuation is the more defensible choice where real tax is at stake.
• An online comparable-sales estimate is a useful early sense-check for an executor, not a substitute for the formal valuation HMRC expects.
• If the property later sells for materially less, ask a solicitor about loss relief — it may allow the estate to reclaim overpaid tax, but the conditions are specific.

Executors are often dealing with this for the first time, at a difficult moment, with real financial consequences riding on getting a technical process right. It's one of the areas of property valuation where the cost of professional advice is genuinely small relative to what getting it wrong — in either direction — can cost the estate.

If you're an executor and unsure whether a formal valuation is necessary for a particular estate, a solicitor handling the probate application can usually give a quick, low-cost steer based on the estate's likely total value and how close it sits to the Inheritance Tax threshold, before you commit to the cost of a full RICS report.