Due diligence
How to check a property discount is real
The short version: a discount is only real if similar homes nearby have recently sold for more. Find three to five sold prices on HM Land Registry, get each home's floor area from its energy certificate, work out the price per square metre, and apply it to the property you are being offered. It takes about 20 minutes and costs nothing.
The four free sources you need
- Sold prices: HM Land Registry price paid data shows what each home actually sold for and when.
- Floor areas: the EPC register lists the total floor area of most homes sold or let in the last ten years.
- Price movement: the UK House Price Index shows how prices in each local authority have moved, so you can adjust older sales.
- What it will look like after works: photos from old portal listings of the comparables, to check they were in a similar condition.
Step by step
- Pick like for like. Same type (terrace, semi, flat), same tenure, similar size and condition, as close as possible, sold in the last 12 months. Three is the minimum; five is better.
- Get each floor area from the EPC register, searching by postcode.
- Work out price per square metre for each: sold price divided by floor area. Throw out any that are far from the others and find out why.
- Adjust older sales by the change in the local House Price Index since they sold.
- Apply the average to the floor area of the property you are offered. That is your estimate of its value in the same condition.
- Compare with the price. The difference is the discount you can evidence, which may be very different from the one in the pitch.
A worked example
A deal is pitched as "worth £160,000, yours for £128,000": a 20% discount on a 70 m² two-bed terrace. Three recent sales nearby:
| Comparable | Sold | Price | Floor area | £ per m² |
|---|---|---|---|---|
| 2-bed terrace, same street | Nov 2025 | £142,000 | 68 m² | £2,088 |
| 2-bed terrace, next street | Feb 2026 | £150,000 | 72 m² | £2,083 |
| 2-bed terrace, same street | May 2026 | £155,000 | 75 m² | £2,067 |
The average is £2,079 per m². At 70 m², that puts the property at about £145,600. The evidenced discount is 12%, not 20%. That might still be a good deal, but you would be paying for a £14,400 gap in the pitch that no sale supports. The figures are illustrative.
Warning signs in a discount claim
- The "value" is an estate agent's marketing figure, an online estimate or the asking price of homes still for sale.
- The comparables are bigger, a different type, or renovated when the deal is not.
- The sales are more than two years old with no adjustment.
- No reason is given for why the seller would accept less.
- The words "guaranteed" or "instant equity" appear anywhere.
How DealSold shows this
Each deal on DealSold labels the end value with where it came from: verified, third-party, the sourcer's own assessment or an AI estimate. Where the sourcer has attached sold comparables from Land Registry, they sit beside it, and three or more lift the end value from the sourcer's estimate to third-party evidence. An Optimism Index flags deals where the value, rent, works and borrowing assumptions are all at the generous end at once. You can still run the checks above yourself, and you should. See how we calculate figures.
Frequently asked questions
What does "below market value" mean?
It means a property is being sold for less than similar homes nearby have recently sold for. It is a claim, not a fact, until you have checked it against sold prices. The figure that counts is what a lender's surveyor will value it at.
Is the asking price on a property portal the market value?
No. Asking prices are what sellers hope to get. Use sold prices from HM Land Registry, which record what buyers actually paid.
How recent should comparables be?
Ideally sold in the last 12 months. Older sales can still help if you adjust them for how prices in that area have moved since, using the UK House Price Index.
Why would anyone sell below market value?
Usually because they value speed or certainty over price: a probate sale, a relocation, a repossession, or a property that cannot get a mortgage in its current state. Ask the sourcer which applies and how they know.
Can a sourcer guarantee a discount?
No. Only a valuation tells you what a lender thinks it is worth, and values can change. Be wary of anyone who promises one.
Deals with the evidence beside every figure
See where each end value came from, and the sold comparables behind it where the sourcer has attached them.
Capital at risk. Property values and rents can go down as well as up.
How we made this guide
Written by the DealSold team. The method uses HM Land Registry price paid data, the EPC register and the UK House Price Index, all free government sources linked above, checked on the date shown. The worked example uses illustrative figures. A desk check is not a valuation; only a qualified surveyor can value a property. Our editorial policy.