Questions to Ask When Buying a Used Car
Published 12 October 2026. Guidance, not legal advice. Figures are correct at the time of writing.
Knowing the right questions to ask when buying a used car can save you from expensive surprises and give you genuine negotiating power. Most sellers are honest, but the wrong answers, or evasive ones, tell you just as much as the right ones. Run through the list below before you part with any money.
Before You Even View the Car
Do your homework from the registration number first. The DVLA record is free to check and shows the make, fuel type, engine size, colour, CO2 output, and current tax and MOT status. BeakCheck also shows the full DVSA MOT history going back to 2005, including every mileage reading at each test and any advisories or failures.
Two things to look for straight away:
- Mileage consistency. If the recorded mileage at one MOT is higher than the mileage at the next test, that is a strong indicator of clocking or a tester error. Either way, investigate before viewing.
- MOT expiry. Driving a car without a valid MOT is an offence except when travelling to a pre-booked test. A car with an MOT that expired months ago may have hidden faults.
The free DVLA and DVSA records do not show outstanding finance, theft markers or insurance write-off categories (A, B, S and N, or the older C and D). For those, you need a paid history check from a recognised provider.
Questions to Ask the Seller
1. Are you the registered keeper, and is this your address on the V5C?
The V5C logbook should match the seller and the address where the car is kept. A seller who cannot produce a V5C, or whose details do not match it, is a serious red flag. Note that the registered keeper is not always the legal owner, which matters if finance is outstanding.
2. How long have you owned the car, and why are you selling?
A short ownership period is not automatically suspicious, but it is worth understanding. A genuine answer costs the seller nothing.
3. Has the car been in any accidents or had any bodywork repairs?
Look at panel gaps, paint depth variations and the colour match around doors and bumpers. Ask for any receipts or insurance documentation.
4. Is there any outstanding finance on it?
If you buy a car with outstanding finance, the finance company can legally reclaim it even after you have paid the seller. Ask to see a settlement letter or run a paid history check before exchanging money.
5. Is the service history stamped and complete?
A full service history (FSH) adds value and shows the car has been maintained. Ask whether the stamps are from franchised dealers or independent garages. Both are acceptable, but gaps in the history are not. Check the service intervals match the mileage on the clock.
6. What do the MOT advisories mean and have they been addressed?
An MOT advisory is not a failure, but it records a defect worth monitoring. Common advisories include tyre wear, brake wear and minor corrosion. Ask whether the seller has had any advisory items fixed since the last test. You can read every advisory yourself for free on BeakCheck.
7. Does the car have any warning lights, and have you had any diagnostic work done?
A seller who says "the light just came on yesterday" should be treated with scepticism. Ask for any garage invoices. A diagnostic file analysis can reveal stored fault codes even if the dashboard light has been cleared.
8. Has the car been remapped?
A remap is not illegal, but it must be declared to the insurer. Ask the seller directly, and look for any paperwork. A reputable remap provider will have supplied a before-and-after dyno sheet or a record of the tune. An undeclared remap can invalidate insurance.
At the Viewing
Run through this quick physical checklist:
| Area | What to look for |
|---|---|
| Oil filler cap | Creamy or frothy residue (possible head gasket issue) |
| Exhaust smoke | Blue (oil), white (coolant), black (rich fuelling) |
| Tyres | Legal minimum tread is 1.6 mm across the central three-quarters |
| Underneath | Fresh oil or coolant stains on the ground |
| Bodywork | Mismatched paint, wavy panels, poorly aligned gaps |
| Interior | Worn pedal rubbers vs low claimed mileage |
Always test drive the car. Listen for knocks, feel for pulling under braking, and check the air conditioning and electrics.
Questions About Tax and ULEZ
Vehicle tax does not transfer when a car is sold. The seller reclaims any remaining full months of tax and the buyer must tax the car before driving it away. You can check current tax status for free from the registration number.
If you are buying in or near London, check the car against the TfL ULEZ checker. Compliance is determined by the exact engine specification, not just the year of manufacture, so the TfL tool gives the definitive answer.
When to Walk Away
Walk away if the seller cannot produce a V5C, if the mileage history does not add up, if there is outstanding finance they cannot settle before sale, or if the car carries a Category A or B write-off marker (both mean the car should not be on the road). A Category S or N marker is not a ban on use, but factor repair costs into your offer.
Take your time. A seller who pressures you to decide on the spot is giving you useful information about how the rest of the transaction will go.
Check any UK car for free
Free DVLA and MOT check, plus the remap verdict for the engine actually fitted to your car.
Thinking about more power?
BeakCheck lists Stage 1 and Stage 2 remap figures for 2,155 UK engines, with the hardware each stage needs and an honest risk rating. Find your engine.