Understanding the Importance of the Red Book Valuation for Probate

A RICS Red Book valuation is the most defensible property valuation available to an executor. It is not compulsory, and a great many estates are administered without one, but where a property is valuable, unusual or close to a tax threshold it is the report that stands up when HMRC asks questions.

This guide explains what the Red Book actually is, what a Red Book valuation gives you that a free appraisal does not, and when it is worth the fee. It applies to England and Wales.

What the Red Book is

The Red Book is a set of mandatory professional standards for valuation, published by the Royal Institution of Chartered Surveyors. Its formal title is RICS Valuation – Global Standards, and it is universally known as the Red Book because of its cover.

The current edition took effect on 31 January 2025 and incorporates the International Valuation Standards. For a UK probate valuation there is a second document that matters just as much: the RICS Valuation – Global Standards: UK national supplement, which came into effect on 1 May 2024 and applies to valuations with a valuation date on or after that date. A UK probate valuation should be prepared under both.

One point that is often stated loosely. The Red Book is mandatory for RICS members and RICS-regulated firms. An estate agent who is not a RICS member is not bound by it and cannot produce a Red Book valuation. That is the practical difference between the two routes, and it is worth being clear about when you are deciding who to instruct.

What the standards require

A valuation prepared under the Red Book must follow a defined process, which includes:

• Agreed terms of engagement setting out the purpose of the valuation and the basis of value.
• Inspection and investigation appropriate to the purpose, rather than a drive-by opinion.
• Use of comparable evidence to support the figure.
• A stated basis of value, a stated valuation date, and any assumptions or special assumptions made explicit.
• Disclosure of any conflict of interest, and compliance with RICS ethical standards.
• A written report in a prescribed form, signed by a valuer who is accountable for it.

That last point is the one that matters most to an executor. You end up with a named professional who has put their name to a figure and can be referred to if it is challenged.

Red Book valuation and market value: a common misunderstanding

You will often see these presented as two competing methods, with the Red Book described as the thorough one and market value as the rough one. That is not right, and it is worth correcting because it leads people to the wrong conclusion.

Market Value is a basis of value defined inside the Red Book. The standards define it as the estimated amount for which an asset should exchange on the valuation date between a willing buyer and a willing seller in an arm’s length transaction, after proper marketing and where the parties had each acted knowledgeably, prudently and without compulsion.

A Red Book valuation for probate reports Market Value. They are not alternatives. One is the professional framework; the other is the basis of value that framework requires the valuer to report against.

So the real distinction is not between two kinds of value. It is between two kinds of evidence for the same figure: an opinion given informally and without liability, or an opinion given under a professional standard by someone accountable for it.

A Red Book valuation is point in time, not long term

A related error worth clearing up. A Red Book valuation does not smooth out short-term market movements or offer a longer-term view of what a property is worth. The standards are explicit that a valuation applies at a stated valuation date, and where values can move materially within a day, at a stated time.

For probate that is exactly what you want, because the figure HMRC requires is fixed to one specific day.

The standard a probate valuation has to meet

Whoever produces the valuation, the legal test is the same. Under section 160 of the Inheritance Tax Act 1984, the value of an asset is the price it might reasonably be expected to fetch if sold on the open market at the date of death.

Two riders follow. The price is not assumed to be reduced on the ground that the whole property is placed on the market at one and the same time, and the costs of selling are not deducted from it.

This is why the instruction matters as much as the instructed. HMRC expects personal representatives to ensure the valuer is properly instructed to give an open market valuation in accordance with section 160, and to question advice that does not on the face of it meet that requirement. A Red Book report prepared for the wrong purpose, or as at the wrong date, does not help you.

Is a Red Book valuation required for probate?

No. There is no legal requirement to obtain one, and no rule that a probate valuation must be produced by a chartered surveyor.

What the law requires is that personal representatives take reasonable care. HMRC’s own guidance says that unless the personal representatives are easily able to determine the market value themselves, it is entirely appropriate for them to obtain a professional opinion of value.

HMRC goes a little further than that in its Inheritance Tax Toolkit, which says that for assets of material value personal representatives are strongly advised to instruct a qualified independent valuer, and that for houses, land and buildings the valuation should meet RICS or equivalent standards. Strongly advised is not the same as required. But on a property of real value it means a Red Book valuation is the course HMRC itself points towards.

When it is worth the fee

A Red Book valuation is usually worth paying for where:

• Inheritance tax is payable, or the estate sits close to a threshold. These are the estates HMRC looks at most closely.
• The property is unusual, in poor condition, has development potential, or is a flat with a short lease.
• The estate includes agricultural, commercial or mixed-use property.
• Beneficiaries disagree about the value, or one of them wants to buy the property from the estate.
• A sale is likely soon after death, because the price achieved will invite comparison with the reported figure.

For a modest estate comfortably below the nil rate band, with an ordinary house in a street of similar houses, a written estate agent valuation given on the date of death basis is usually proportionate. The fee for a Red Book report reflects the complexity of the property, so it is a judgement about proportion rather than a rule.

What happens if HMRC questions the valuation

HMRC does not assess land values itself. It refers them to the Valuation Office Agency, and the District Valuer considers the reported figure against survey details, sale prices of the property or comparable properties sold around the date of death, and the data the VOA holds for council tax purposes.

A referral is routine and does not imply anything is wrong. Where the VOA cannot accept the figure as a fair reflection of open market value, it opens a discussion. That discussion is a very different experience depending on whether you are holding a Red Book report from a named surveyor or a printout from a property portal.

Penalties depend on behaviour, not on being wrong

It is sometimes suggested that an inaccurate valuation leads to penalties. That overstates it. Under Schedule 24 of the Finance Act 2007, penalties attach to carelessness or deliberate understatement. An inaccuracy made despite taking reasonable care carries no penalty at all.

That is precisely the value of a professional valuation: not that it guarantees the right number, but that it evidences reasonable care.

There is one trap. An innocent error that you later discover and do not report is treated as careless. If something comes to light after you have submitted the figures, tell HMRC using form C4.

Why the valuation matters after the inheritance tax is settled

The date of death value becomes the base cost for capital gains tax if the property is later sold, so a figure set too low simply moves tax from one place to another rather than saving any.

There is a further point that makes a defensible valuation more valuable, not less, in a non-taxable estate. The probate figure only binds HMRC as the base cost where it was ascertained for inheritance tax, meaning HMRC actually used it to arrive at a tax charge. Where no inheritance tax was payable, nothing was ascertained, and HMRC can look at the figure afresh when the property is sold. In other words, the estates where people assume the valuation matters least are the ones where the number is least protected.

Where the Red Book valuation fits in the wider job

The property is usually the largest asset but it is not the only one that needs valuing. Our guide to how to value an estate for probate covers the estate as a whole, including contents and chattels, and house valuation for probate purposes goes into the property side in detail, including flats, leasehold, tenanted property and jointly owned shares.

For the figures the valuation feeds into, see gross and net value of an estate, what is an excepted estate and help with the IHT400 form. Our guide to an executor’s responsibilities for probate property covers looking after the property itself while the administration runs.

You can find a probate valuer through The Probate Network.

Frequently asked questions

What is a RICS probate valuation?

It is a valuation of a property for probate purposes, carried out by a RICS member under the RICS Valuation – Global Standards, known as the Red Book. It reports the open market value at the date of death, in a written report that sets out the basis of value, the valuation date, the assumptions made and the comparable evidence relied on. It is the most defensible form of evidence an executor can hold.

Is a Red Book valuation required for probate?

No. There is no legal requirement, and an estate agent’s written valuation given on the date of death basis is acceptable. What the law requires is reasonable care. That said, HMRC’s own Inheritance Tax Toolkit strongly advises a qualified independent valuer for assets of material value and says that houses, land and buildings should be valued to RICS or equivalent standards, so on a valuable property it is the route HMRC points towards.

What is the difference between a Red Book valuation and market value?

They are not alternatives. Market Value is a basis of value defined within the Red Book itself, and a Red Book valuation for probate reports Market Value. The real difference is in the evidence: a Red Book valuation is produced by a qualified valuer under a mandatory professional standard, with an inspection, stated assumptions and a signed report, whereas an informal appraisal is an opinion given without liability.

How much does a Red Book valuation cost?

Fees depend on the property, since the work involved in valuing a farm or a short-lease flat is not the same as a standard semi-detached house. It costs more than a free estate agent appraisal, and on a taxable estate it is generally money well spent. Get a quote for the specific property rather than working from a general figure.

Which edition of the Red Book applies?

The current edition of RICS Valuation – Global Standards took effect on 31 January 2025. For UK valuations the UK national supplement, effective 1 May 2024, applies alongside it. A valuation report should state which standards it was prepared under.

This article is for general guidance only and applies to England and Wales. It does not constitute legal, tax or financial advice. Rules, thresholds and professional standards can change and every estate is different. For advice on your own circumstances, speak to a qualified professional. You can book a free legal consultation through The Probate Network.