How to check a
used car before
buying

Check the MOT history

This is the single most valuable free check you can do before buying a used car. The DVSA keeps a full record of every MOT test a vehicle has taken — every pass, every failure, every advisory, and crucially, the mileage recorded at each test.

What you're looking for:

• Repeated failures on the same item — brakes, suspension, emissions — which suggest a persistent problem the owner keeps patching
• Any dangerous or major failures in recent tests, especially on structural items
• Advisories that appear on two or more consecutive tests — these are the tester saying "this will fail next time"
• Gaps in testing — if a car hasn't had an MOT for two years, what was it doing?
• Mileage consistency (see step 2)

Verify the mileage

Mileage fraud — clocking — is surprisingly common in the UK used car market. A clocked car can be worth thousands of pounds less than its apparent mileage suggests, and the mechanical wear is hidden.

MOT records are your best free defence. Every MOT records the odometer reading. If those readings don't go consistently upward — if there's a dip, a flat section, or a sudden jump — the mileage has been tampered with.

Also cross-reference the service history if the seller has it. Service stamps should show progressively higher mileage readings, and a full service history with low mileage is unusual enough to be suspicious.

Check the tax and SORN status

Before you even arrange to view a car, check it's taxed. An untaxed car is either being driven illegally, or it's been declared off-road (SORN). Neither is automatically a dealbreaker, but you want to know.

A SORN car may have been sitting unused for an extended period — which raises questions about whether fluids have degraded, tyres have flatspotted, or brakes have seized.

regadvisor.co.uk shows the current tax and SORN status alongside MOT history — all from the DVLA, all free.

What about road tax due dates?

Check when the tax is due for renewal. If it expires soon, you'll need to tax it immediately after purchase. This isn't a problem — just something to factor in when negotiating price.

Check for outstanding finance

This is the check that trips up the most buyers. If a car has outstanding finance against it — a PCP agreement, a hire purchase loan — the finance company technically owns the car, not the seller.

If you buy a car with outstanding finance and the seller doesn't pay it off, the finance company can repossess the car from you. You lose both the car and your money.

You need a paid check from a company like HPI, Experian, or the AA to verify this. It typically costs £10–20 and is absolutely worth it on any significant purchase.

A full paid check will also show if the car has been written off in a category A, B, S, or N incident, or if it's been reported stolen.

Inspect the car in person

No online check replaces seeing the car with your own eyes. Here's what to look for:

Bodywork and paint

• Mismatched paint panels — different shades or textures suggest accident repair
• Wavy panel gaps that should be straight — a sign of poor accident repair
• Overspray on rubber seals, glass edges, or plastic trim
• Rippling or dimpling in panels visible in raking light

Under the bonnet

• Oil level and condition — black sludge suggests poor maintenance
• Coolant level and colour — brown or rusty coolant is a problem
• Mayonnaise-like residue under the oil cap — could indicate head gasket issues
• Fresh underseal or paint on the engine bay floor — potential accident or flood damage cover-up

On the test drive

• Brakes — any pulling, grinding, or sponginess
• Steering — should feel positive and not wander
• Gear changes — smooth, no crunching or hesitation
• Warning lights — none should come on and stay on
• Unusual smells — burning, exhaust in the cabin, musty (damp)

Use AI-powered buying advice

Once you have the registration number, regadvisor.co.uk can generate model-specific buying guidance based on the car's make, model, year, and MOT history. Switch to "I'm Shopping" mode before running the check.

This will highlight known issues for that specific model — common failure points, what to look for at inspection, what questions to ask the seller, and what the car costs to run. It's generated by AI so treat it as a starting point rather than gospel, but it's a genuinely useful shortcut.