Capital Gains Tax Valuation
12 November 2026
A Capital Gains Tax valuation fixes the value of a property at a past date, so you can work out the gain when you sell it. You need one when you did not buy the property at arm's length, for example because it was gifted or inherited, or when HMRC rules say market value applies instead of the price paid.
Quick answer: Your gain is usually the sale price minus what you paid and certain costs. Where the property was inherited, gifted, transferred between family members or owned since before 31 March 1982, HMRC uses market value at a set date instead. A written valuation by a qualified valuer supports the figure in your return.
Key Takeaways
Capital Gains Tax applies to gains on property that is not your main home.
Inherited property usually uses its value at the date of death as the starting point.
Gifts and transfers between connected people use market value, not the price paid.
UK residents selling UK residential property must report and pay any tax due within 60 days of completion.
HMRC can check a valuation, so a reasoned report matters.
How the Gain Is Worked Out
Capital Gains Tax is charged on the profit when you sell or give away an asset that has gone up in value. For property, that usually means buy-to-let homes, second homes, inherited houses and business premises. You do not usually pay it on the home you live in as your main residence, although there are conditions.
The gain is broadly the amount you receive minus your acquisition cost, with deductions for some buying and selling costs and for improvements that added to the value. The difficulty comes when there is no clear purchase price to start from.
When You Need a Capital Gains Tax Valuation
HMRC uses market value rather than the actual price in several situations. In each one, you need a figure for what the property was worth on a specific date.
You inherited the property, so the value at the date of death is usually your starting point.
Someone gave you the property, or you gave it away.
You sold or transferred it to a family member or business partner.
You have owned it since before 31 March 1982.
You are selling part of a property or land and need to split the cost.
A valuation can also help if you lost the original paperwork and need to show what improvements added. Keeping records from the start is far easier. If you run a trade business, the same habit of tracking costs that helps you price your services will help here too.
Retrospective Valuations
Most CGT valuations look back in time. A valuer works out what the property would have sold for on the relevant date, using sales of similar homes from around then, the condition and size of the property at that time, and the market conditions of the day. Photos, old estate agent details and records of works help the valuer get it right. Our guide to RICS survey types explains how a valuation differs from a survey.
Because the date is in the past, the quality of the evidence matters. A figure that seems too low or too high may be queried. Using a RICS Registered Valuer gives you a report that follows recognised standards and explains how the figure was reached. If the property is in London or Essex, a Capital Gains Tax valuation from Gibsons Surveyors gives you a written report to keep with your tax records.
Reporting and Paying on Time
GOV.UK says that if you are a UK resident and sell a UK residential property that gives you Capital Gains Tax to pay, you must report it and pay the tax within 60 days of completion. That deadline arrives quickly, so arrange any valuation before you sell rather than after.
You may also need to include the gain in your Self Assessment return. If you are a sole trader or landlord, check how your reporting changes under Making Tax Digital for Income Tax, as that affects how you keep records through the year.
If HMRC Queries the Value
HMRC can ask the Valuation Office Agency to review a property valuation. You can also ask HMRC to check a valuation after the sale but before you file, using form CG34. A clear, reasoned report from a qualified valuer puts you in a much stronger position if questions come up.
Getting the Right Advice
A valuer gives you the figure, but they do not work out your tax. An accountant or tax adviser can tell you which reliefs apply, which costs you can deduct and how to report the gain. Bring the valuation report to that conversation so everyone works from the same number.
Frequently Asked Questions
Do I pay Capital Gains Tax on an inherited house?
You do not pay it when you inherit. You may pay it when you sell, on any rise in value since the date of death. The value at death is usually your starting figure.
Can I use an estate agent's valuation for Capital Gains Tax?
An agent's opinion can be a starting point, but a formal report from a qualified valuer is stronger if HMRC checks the figure. If you would like some help with this, get in touch with our team.
What is a retrospective valuation?
It is a valuation of a property at a past date, such as the date of a gift or death, based on evidence from around that time.
How long do I have to report Capital Gains Tax on property?
GOV.UK says UK residents selling UK residential property must report and pay any tax due within 60 days of completion.
Does Fin-Tech UK value property or give tax advice?
No. Fin-Tech UK is an independent guide. We explain how things work, but we do not value property, give personal tax advice or endorse individual firms.
To check the reporting rules yourself, see the GOV.UK page on how to report and pay your Capital Gains Tax.