What to look for when buying a used car: the complete checklist

Knowing what to look for when buying a used car is the difference between years of cheap, dependable motoring and a wallet-emptying breakdown six weeks in. Cars don't usually give up their secrets easily, either. The paint looks tidy, the mileage seems plausible, and the photos in the ad were taken on a nice, sunny afternoon.

After years of buying, fixing and (occasionally) wrecking used cars, I can tell you the ones that bite are never the ones that looked rough. Hidden accident damage, clocked mileage, outstanding finance, write-offs sold as clean cars – none of them announce themselves during a quick walkaround. Most buyers only discover them after the money has changed hands.

In this guide, I'll walk you through the checks I do before buying a used car, from the history checks you can run before leaving home to the test-drive that can help uncover problems sellers would rather you didn't find.

What to check when buying a used car

When buying a used car, there are five areas you should check, and the order matters. Start with the vehicle's history, as it’s quick, inexpensive, and can potentially save you a wasted journey and the cost of a pre-purchase inspection. Once the paperwork checks out, it's time to inspect the car itself.

The five things to check when buying a used car, in order:

1. 1.Vehicle history

2. 2.Physical exterior and body

3. 3.Interior and electrics

4. 4.Engine and mechanical condition

5. 5.Test drive

1. Vehicle history checklist: what to verify

Before you book a viewing, run the car through these seven background checks. Most of them take minutes, several are free, and they might just save you thousands.

Service history

When I'm looking at a used car, the service history is one of the first things I check. It tells you whether the car has actually been maintained or just driven from problem to problem.

"Full service history" should mean a record that follows the manufacturer's schedule, ideally main-dealer stamps backed up by invoices, or a digital record you can verify by VIN at a franchised dealer.

Number of previous keepers

High turnover isn't always a bad sign, but several owners in a short period are worth a closer look. When choosing between two similar cars, I'd take a slightly higher-mileage car with full stamps and one owner over a low-mileage car that's been passed around five owners with patchy paperwork. The story of the car matters more than the number on the odometer.

MOT history

The free check at gov.uk shows the mileage recorded at every test back to 2005, plus any advisory, pass, or fail. Mileage that falls between tests or does nothing for years is the easiest clocking clue you'll ever get.

Outstanding finance

If the car was bought on PCP, HP or a secured loan and the finance hasn't been cleared, the finance company still owns it. Buy the car privately, and they can lawfully come and repossess it from you, with no refund. Always ask for a settlement letter.

Write-off category

This is one of the most important checks you can make, as a write-off marker can affect everything from the car's value to its insurability.

Under the ABI Salvage Code, Cat A and Cat B insurance write-offs must be scrapped or broken for parts and cannot legally return to the road. Cat S (structural repairs) and Cat N (non-structural repairs) can be re-registered and sold, but the seller must declare them, and they typically sell for 20 to 40 per cent less than a car without damage.

Stolen vehicle check

A car flagged on the Police National Computer still legally belongs to its original owner. Buy it, and you lose both the car and your money when it's recovered. Cross-check the VIN and engine number on the V5C against the numbers stamped on the car itself, since cloned plates often disguise stolen vehicles.

Odometer fraud

Selling a car with a falsely reduced mileage (also known as ‘odometer rollback’ or ‘clocking’) is illegal. Where the seller is a trader, it is a ‘misleading action’ under the Digital Markets, Competition and Consumers Act 2024. If the seller is a private individual, it can still be fraud under the Fraud Act 2006. Modern digital clusters can be wound back with cheap OBD tools in minutes.

Most of these checks (except service history) are bundled into a single carVertical report, which lets you check whether the car has been in an accident, confirm theft and finance status, and verify the mileage trend in minutes off the VIN or registration. My rule is simple: ask to see the VIN and put it through a history check before agreeing a price. If the seller flinches at that, you’ve got your answer right there.

I've changed my mind on cars plenty of times after running the report. Cars that looked mint until they showed three previous owners in 18 months or a sudden mileage gap that nobody mentioned.

It works the other way, too. I spotted a listing for a supercharged Porsche 911 at £10,000 and assumed it had to be a scam. Ran a carVertical check expecting the worst, and got green ticks all round, low owners, and only 62,000 miles on the clock. Agreed a deal over the phone. The report gave me the confidence to go for it.

The free gov.uk MOT history check is also worth running on every shortlisted car, though the MOT data alone won't surface damage, finance or theft records. It’s worth having alongside a full background check, but not as a replacement.

2. Physical exterior and body check

Once the paperwork is clean, walk around the car in daylight. Take your time, take photos, and put your hands on the metalwork. A lot of common used car problems can reveal themselves if you know where to look.

• Panels and paint. Uneven panel gaps, mismatched paint shades, overspray on door rubbers or window seals, wheel arch lips that have been bent and pulled back, a bonnet sitting proud on one side – all signs of accident repair. A paint-depth gauge can reveal if filler was involved.
• Rust. UK winter road salt is brutal on older metal, so check the sills, rear wheel arches, underside, boot floor and spare-wheel well, sunroof drains, fuel filler and suspension.
• Tyres. The UK legal minimum tread depth is 1.6mm. Each illegal tyre is three penalty points and a fine of up to £2,500. Look for cracking, mismatched brands and uneven wear.
• Glass. Windscreen damage is an MOT failure if it is over 10mm in the driver's area or 40mm anywhere else. Test the wipers and washers, too.
• Suspension. Press down hard on each corner and let go. It should rebound once, cleanly. Two or more bounces mean worn dampers.
• Lights. Test the lot: headlights (dipped and main), front and rear fog lights, indicators, hazards, brake, reversing and number-plate lights.
• Boot. Lift the boot floor and inspect the spare-wheel well for water staining and rust, which is a classic flood indicator. Confirm that the spare or repair kit, the jack and the locking wheel-nut key are all there.
• Underbody. Have a look at the subframe and exhaust for any suspicious corrosion, fluid leaks and jacking damage.

3. Interior and electrics checks

The cabin is where clocking gives itself away. A car claiming 38,000 miles with a shiny steering wheel, a polished gear knob, worn pedals and a collapsed driver's seat bolster has done a lot more than the seller claims. Compare what you see against the vehicle’s recorded mileage.

Other important checks to make:

• Warning lights. Turn the ignition on without starting the engine and watch every light light up, then start the car and check that each one goes out. A light that never illuminates may have had its bulb removed to mask a fault.
• Air conditioning. It should blow cold within a couple of minutes. A re-gas in 2026 typically runs £50 to £90, but an actual repair is more.
• Heating and demister. Test front and rear, plus heated screens and heated mirrors.
• Electric windows, mirrors and central locking. Every switch on every door. Same for the sunroof, if fitted.
• Infotainment. Touchscreen, reversing camera, Bluetooth pairing, parking sensors, satnav, and software version. If there’s an aftermarket head unit, ask what the original did before it was replaced.
• Seatbelts. Smooth retraction, no fraying, click and release on every belt, including the rear ones.
• Smells. Damp or musty points to water ingress and could be flood damage signs. A sweet, oily smell from the vents can mean a leaking heater or head-gasket trouble. Heavy air freshener could be trying to hide something.
• Carpets and boot floor. Lift them. Water staining and rust underneath are the clearest flood indicators you will find without a workshop.
• Keys. Confirm there are at least two. A replacement smart key in 2026 usually costs £200 to £600, depending on the manufacturer.

4. Engine and mechanical checks

Before you start checking the mechanicals, make sure the car is genuinely cold. Ask the seller not to start or move the car before you arrive, then watch and listen as it fires up from properly cold. A warmed-up engine hides knock, smoke, and a rough idle that a cold start can quickly uncover. If you turn up and the bonnet is warm, be wary.

• Oil. Pull the dipstick. Brown or black is normal. Milky, foamy grey "mayonnaise" usually means coolant in the oil (head gasket or cracked block).
• Coolant. Correct level, no rusty film or brown sludge under the cap. Oily contamination is a head-gasket issue.
• Visible leaks. Look under the car and around the engine bay: engine oil (brown or black), coolant (pink, green or orange), brake fluid (clear yellow), and power-steering fluid. Note where it is coming from, not just that it is there.
• Engine bay. A bit of dirt is normal and healthy. A suspiciously clean bay (often used to hide leaks) and heavy oil splatter are both red flags. Look for any wiring in poor condition, loose hoses and missing cover bolts.
• Belts and hoses. Squeeze the rubber: it should be firm, not cracked or spongy. Check the auxiliary belt. Ask whether the car has a cam belt or a timing chain, when it was last done, and at what mileage.
• Engine running. Listen for top-end ticking, bottom-end knock, turbo whine, and exhaust smoke.
• Exhaust smoke. A brief puff on start-up is normal. Continuous blue smoke is burning oil. White smoke is coolant or, on a cold morning, condensation. Black smoke is over-fuelling.
• Gearbox. Manual: a clean clutch bite and no crunch on any gear. Automatic: smooth shifts with no flare or slip.

5. What to check during the test drive

The test drive is your chance to see how all the mechanical components work together once you're out on the road.

Aim for 20 to 30 minutes on a mixed route: motorway or dual-carriageway, urban streets, and a stretch of uneven B-road. Anything that feels even slightly off probably is, so trust your instincts.

While you are driving, run through these:

• Steering. Any vague steering, vibration through the wheel, clunks on full lock, or a dead spot off-centre – anything that feels off is worth flagging.
• Brakes. Pulling to one side under braking, judder at speed (warped discs), spongy pedal travel, a faint knock over speed bumps that the seller swore wasn't there. On a hill, does the handbrake actually hold?
• Suspension. Drive over potholes, speed bumps and broken tarmac and listen for knocks and rattles – worn bushes and dampers give themselves away on rough surfaces.
• Gearbox under load. Run through every gear including reverse – a slow or crunchy change into reverse is a classic gearbox wear sign. Kickdown on an auto. A hill start on a manual.
• Engine under load. When you join a faster road, accelerate assertively in a lower gear, as that’s where worn engines smoke. Lift off and feel for engine braking – a car that doesn't pull cleanly or blows smoke under load has something to hide.
• Warning lights. All should go out once the engine is running and stay off under load – a light that comes on and stays on means there's a fault the seller may not have mentioned.
• Driver assistance. Test cruise control, lane assist, parking sensors and the reversing camera if fitted – these are expensive to fix and sellers often know they're not working.

Set your budget before you start looking

Now that you know what to inspect, it's worth taking a step back. The best used-car purchases are often made long before you ever arrange a viewing.

Set a realistic budget before you start browsing, not after you have fallen for a car. Total cost of ownership in the UK breaks down into seven parts, and the purchase price is just one of them.

• Purchase price. The average UK used car sold for around £17,306 in May 2026, according to the Auto Trader Retail Price Index, up 0.7% year on year.
• Insurance. According to ABI, the average comprehensive premium is at £560. Young drivers pay much more, with 17 to 24-year-olds averaging £1,099.
• VED (road tax). Cars registered before April 2017 are taxed by CO₂ emission band (A to M), so the figure stays the same each year but varies by car. Cars registered after April 2017 pay a CO₂-based first-year rate, then a standard rate of £200 from 2026/27. The Expensive Car Supplement of £440 a year (2026/27) is added in years 2 to 6, with higher thresholds for EVs.
• MOT. The DVSA maximum fee is £54.85, though most garages charge between £30 and £45. The first MOT is due three years after first registration, then annually. Budget £150 to £250 a year overall, once likely repairs are included.
• Fuel. At current rates, 8,000 miles a year at 45mpg petrol at £1.45 a litre is around £1,170, so bear it in mind.
• Servicing. Interim services £90 to £180, with full services £180 to £400.

Depreciation also belongs on this list, and it is steepest in year one. Buying a car at around three years old lets the first owner take the biggest hit.

Decide how you're going to pay

The right way depends on what you have, what you can borrow, and how much exposure you want.

One protection worth knowing about: under Section 75 of the Consumer Credit Act 1974, paying between £100.01 and £30,000 by credit card (even just the deposit) makes the card provider jointly liable with the seller if the car turns out to be misdescribed, defective or undelivered. A small deposit on a credit card gives you a lot of options if things go wrong.

Paperwork and legal checks

Walking away from a deal because the paperwork doesn't add up costs you nothing. Check every item on this list before money changes hands.

• V5C logbook. The current version is red. Hold it up to the light: there should be a "DVLA" watermark, and the VIN, engine number and keeper details must match what is on the car. A blue (pre-2011) V5C is a red flag. Stolen V5C serial number ranges (BG8229501 to BG9999030, and BI2305501 to BI2800000) are not in circulation and never will be so if a seller produces one in those ranges, walk away and report it to the police. Never accept a photocopy.
• V5C/2 green new-keeper slip. This is the slip you need to tax the car straight away. If the seller cannot find it, you can still tax the car using the V5C/2 reference number, and the registered keeper can request a replacement V5C from DVLA.
• MOT certificate. The legal record is the online one. Verify by registration plate at gov.uk.
• Service history. A stamped book, invoices and receipts, or a digital print-out you can verify by VIN at a franchised dealer.
• Finance settlement letter. If the car was financed and the finance has now been settled, get written confirmation from the lender.
• Bill of sale. Not legally required in the UK, but strongly recommended. Two copies, signed by both parties, with the date, price, full names and addresses, VIN, registration and recorded mileage. For private sales, include "sold as seen, tried and approved".
• Tax before driving. Since October 2014, car tax does not transfer with the sale. The seller is auto-refunded from the date of sale, and you must tax the car before driving it. Do it online, by phone or at a Post Office using the V5C/2 reference.
• Insurance before driving. This is for every UK vehicle that is not on a SORN. The car must be insured in your name before it moves.
• Notify DVLA. Tell DVLA online about the change of keeper. It is free, instant, and there are penalties if you don’t do it.
• Don't forget to collect. Both keys, the locking wheel-nut key, any infotainment or radio codes, the satnav SD card if the car has one, the spare wheel and the service book.

Choose between a dealer and a private seller

Is it better to buy from a dealer or privately? From a dealer, you are covered by the Consumer Rights Act 2015. Privately, you mostly are not, so for most buyers who want a safety net, a dealer is the better choice. Confident buyers who know what they are looking at can save roughly 10 to 15 per cent by going private, but the risk sits entirely with them.

What the Consumer Rights Act gives you (trader sales only). Per the law, a used car must be of satisfactory quality, fit for purpose and as described, and if it isn't, you have specific rights when a dealer sells you a faulty car. You get a 30-day short-term right to reject for a full refund, and from 30 days to six months you give the trader one chance to repair or replace, with the burden of proof sitting on them (any fault is presumed to have been present at sale). After six months, that burden shifts over to you.

What you get from a private seller. Caveat emptor, or buyer beware. The seller only has to describe the car accurately and have the legal right to sell it. The Misrepresentation Act 1967 still protects you against outright lies, but that is about the limit of it.

Negotiate and finalise the deal

You can start to negotiate the price even before seeing the car. Call or message the seller first to confirm the spec, ask why it is for sale, run through any mechanical issues and dig into any accident history (as accident damage means big discounts).

Listen for things the ad doesn't mention, as an inexperienced seller will often give details on the phone that didn’t appear in the listing. Don't ask what the lowest price is at this stage, just turn up as a serious, prepared buyer instead.

Then, build your price:

• Research the market. Look up the same make, model, age and mileage on Auto Trader, Motors and CarGurus.
• Use the history report as evidence. MOT advisories, prior accident records, multiple owners in a short period, a Cat S or Cat N marker. Each one is a documented reason to pay less.
• Cost imminent work. Tyres near 3mm, an MOT due in a fortnight, a cam belt due at the next service: all of those are repair invoices waiting to happen.
• Be willing to walk. There is always another car. A polite "thanks, but no thanks" is a powerful negotiating tool.
• Time the dealers. End of the month and end of quarter, when finance and volume targets bite, give you the most leverage. Negotiate the car price first, then any part-exchange separately, so you can see what each is actually worth.
• With private sellers. Cash is still convincing, within reason. Insist on seeing the car in daylight at the seller's own driveway, which also confirms the V5C address matches. Bring a mechanic friend or, better, arrange a pre-purchase inspection.
• On agreement. Pay any deposit by credit card so Section 75 covers you, then agree the collection-day checks and the final payment method in writing.

Main questions to ask the seller when buying a used car

Ask these on the phone or by message before you travel. A confident seller will answer openly and have the documents to hand, whereas an evasive seller often deflects, rushes you, or makes excuses for missing paperwork.

1. 1.Why are you selling? Context is important. Vague or shifting reasons are a red flag.

2. 2.Are you the registered keeper on the V5C, and at this address? Confirms the right to sell. "It's my mate's car" or "I'm selling it for someone" means walk away unless the actual registered keeper is there.

3. 3.How many previous keepers has it had? Several keepers in a short period is something worth asking more about.

4. 4.Is there any outstanding finance on the car? If yes (or "I'm not sure"), stop until they produce a settlement letter from the lender.

5. 5.Do you have the full service history? No history means the upkeep is unknown, and solid grounds for a discount.

6. 6.When was the cam belt or chain last done, and at what mileage? No answer on a belt-driven car means you are about to spend £300 to £700.

7. 7.Has it ever been in an accident or been declared a write-off? Cross-check the answer against the carVertical report. And get the answer in writing.

8. 8.Are both keys present? Only one key means a £200 to £600 replacement.

9. 9.When is the MOT due, and were there any advisories at the last test? Verify on gov.uk.

10. 10.Is the mileage accurate, and does it match the MOT history? Any differences point to clocking.

11. 11.Was it ever used as a taxi, driving-instructor car or rental? Heavy commercial use shortens the service life and reduces resale value.

12. 12.May I take it to an independent mechanic for a pre-purchase inspection? A refusal is one of the biggest red flags in used car buying.

For a longer working list, see the guide to used car buying questions.

Remember, not every flaw should put you off a car. The trick is knowing which issues are cosmetic and which can turn into expensive problems later.

I’ll compromise on paint condition, a slightly tired interior, non-original wheels, small cosmetic stuff. What I’ll never compromise on: service history, accident history, and structural integrity. Those are the things that cost you proper money down the line.