House Valuation for Capital Gains Tax
Capital gains tax (CGT) can apply when you sell a property that isn't your main home — a second home, a buy-to-let, or one you inherited.
Working out the gain means knowing the value at two points in time, and in some cases HMRC will expect a formal valuation, not a rough guess.
Estimate the likely gain first
The tool above gives you a fast, data-backed ballpark of today's value — useful for seeing roughly what your gain (and therefore your tax) might be before you get formal figures.
When you need a formal valuation for CGT
You generally need a defensible market value (not just an online estimate) when:
- You inherited the property — you need its value at the date of death (the "probate value") as your starting cost.
- You sold or gave it to a connected person (like a family member) at less than market value.
- You need the value at a specific historic date that HMRC's rules require.
For these, a RICS "Red Book" valuation from a chartered surveyor is what stands up to HMRC. You can also ask HMRC to check a valuation in advance with a Post-Transaction Valuation Check (form CG34).
Can I use an online estimate on my tax return?
Not as the official figure — HMRC wants a supportable market value, and an area-average estimate can't see your specific home. But it's a genuinely useful sense-check of whether a valuation you've been given looks right, and of the tax you might face.
Working out your gain, roughly
Your gain is the sale price minus what you paid (or the probate value if inherited), minus buying/selling costs and any qualifying improvements, minus your annual CGT allowance. Your main home is normally exempt under Private Residence Relief.
Track it for free. Pop your email into the tool above and we'll send a free update when prices in your area move — no account, no estate-agent calls, no catch.
Frequently asked questions
Do I pay capital gains tax on my main home?
Usually no — your main residence is normally exempt from CGT under Private Residence Relief. CGT typically bites on second homes, buy-to-lets and inherited property you didn't live in.
What valuation does HMRC accept for capital gains tax?
A market value you can support — for anything significant that means a RICS 'Red Book' valuation from a chartered surveyor. You can pre-agree it with HMRC using a Post-Transaction Valuation Check (CG34).
More house valuation guides: For selling · For staircasing · For equity release · How much has it gone up? · For divorce · For probate · Without an estate agent
For the full tool and method, see our house value calculator and how we estimate home values.
General information only, not a formal valuation. Estimates use area averages and can't see your specific home — for a precise figure use a RICS surveyor or local agent.
