The Complete Used Car Buying Guide

1. Before You Start Looking

Before you even browse listings, it pays to have a clear idea of what you need. Consider the following:

• Budget: Set a realistic budget that includes insurance, tax, fuel and potential repairs — not just the purchase price. A general rule is to budget 10-15% on top of the purchase price for first-year running costs.
• Body type: Do you need a hatchback for city driving, an estate for family life, or an SUV for rural roads? Think about practicality over style.
• Fuel type: Petrol is generally cheaper to buy but more expensive to fuel. Diesel is better for high-mileage drivers. Hybrids and electric vehicles have lower running costs but higher purchase prices. Consider the ULEZ zones if you drive in London.
• Insurance group: Get quotes before you buy, especially if you're a younger driver. A car that's cheap to buy can be expensive to insure.
• Reliability: Research common faults for models you're interested in. Our MOT history checker is a great starting point — check several examples of the same model to see if certain defects come up repeatedly.

2. How to Read an MOT History

The MOT history is one of the most valuable free resources available to used car buyers. Here's how to make the most of it:

Pass Rate

A vehicle with a 100% pass rate has never failed an MOT — that's the ideal. Anything above 80% is generally good. Below 60% suggests the car has had issues. However, context matters: a 10-year-old car with occasional fails is less concerning than a 3-year-old car that's already failed twice.

Test Frequency

Look for consistent annual testing. Gaps of more than 14 months between tests can indicate the car was off the road — possibly due to damage repair, financial issues or abandonment. Our tool flags MOT gaps automatically.

Mileage Trend

The odometer reading is recorded at each MOT. These should increase steadily year on year. If the mileage drops between tests, it could indicate the odometer has been tampered with (clocking). Our tool detects and flags this automatically.

Defect Patterns

Recurring defects are a red flag. If the same component keeps failing — especially brakes, suspension or steering — it might indicate a deeper structural or design issue with that particular car.

3. Checking Mileage & Spotting Clocking

Mileage clocking — winding back the odometer to make a vehicle appear lower-mileage — is unfortunately still common in the UK. Here's how to protect yourself:

• Check the MOT mileage history: Use our free MOT checker to see every recorded mileage reading. The numbers should go up consistently. If they drop between tests, that's a major red flag.
• Cross-reference the service history: If the seller provides a service book, check the mileage stamps match the MOT readings.
• Look at wear: A car claimed to have 30,000 miles but with a heavily worn steering wheel, pedals and driver's seat is suspicious.
• Average UK mileage: The average UK car does 7,000-10,000 miles per year. Significantly lower than this might be genuine (elderly owner, second car) or could indicate clocking.
• Digital odometers: Don't assume digital odometers can't be clocked — they can, and professional clocking services are widely advertised online. Always verify with independent records.

4. Understanding MOT Defects

Since 2018, MOT defects fall into four categories:

When reviewing a car's history, pay close attention to dangerous and major defects. Our tool also classifies major defects as "easy fixes" (tyres, bulbs, wipers) or "serious" (structural, brakes, steering) to help you gauge the true severity.

5. Timing Chains vs Cambelts

Every engine uses either a timing chain or a cambelt (timing belt) to synchronise the crankshaft and camshaft. Understanding which your car has is crucial:

Timing Chain

• Made of metal — typically lasts the life of the engine
• Does not have a scheduled replacement interval in most cases
• Can stretch or develop tensioner issues over time
• Listen for a rattling noise on cold starts — this can indicate a worn chain or tensioner
• Common in: BMW, Toyota, Mazda, Nissan, most modern petrol turbos

Cambelt (Timing Belt)

• Made of rubber — must be replaced at set intervals (typically 60,000-100,000 miles or 5-10 years)
• If it snaps, the engine can be destroyed — catastrophic, often uneconomical to repair
• Replacement costs £300-£600+ depending on the car
• Always ask when it was last changed and request proof (receipt/stamp in service book)
• Common in: Peugeot, Citroen, Renault, Volvo, Fiat, Subaru, older VW diesels

Our Used Car Checker automatically tells you whether a vehicle is likely to have a chain or belt based on the make and model.

6. Checking for Recalls

Vehicle manufacturers issue safety recalls when a defect is discovered that could affect safety. Key facts about recalls:

• Recalls are free — the manufacturer pays for all parts and labour
• You can get recall work done at any authorised dealer for that brand
• Check the official GOV.UK vehicle recall checker
• Our tool cross-references known significant recalls when you search for a vehicle
• When buying, always ask the seller if recall work has been completed — the dealer can verify this

7. What to Check When Viewing a Car

Armed with the MOT history from our tool, here's your physical viewing checklist:

Exterior

• Check all panels for colour mismatches, uneven gaps or rippled paint — signs of accident repair
• Look underneath for rust, especially on sills, arches, subframe and chassis rails
• Check all tyres for even wear (uneven wear suggests suspension/alignment issues)
• Check for chips, cracks or damage to the windscreen
• Open and close all doors, boot and bonnet — they should move smoothly

Interior

• Check the dashboard for warning lights with the engine running — none should be lit
• Test all electrics: windows, mirrors, air con, heating, radio, USB ports
• Check for damp, mould or musty smells (water leaks are expensive to fix)
• Look at pedal and steering wheel wear — does it match the claimed mileage?
• Check the service history book and any receipts

Under the Bonnet

• Check the oil — it should be golden/brown, not milky (milky = head gasket issue)
• Check coolant level and condition
• Look for oil leaks, corroded battery terminals, or cracked hoses
• The engine should start easily and idle smoothly

8. The Test Drive Checklist

Never buy a car without driving it. Here's what to assess:

• Cold start: Arrive before the seller has warmed up the car. A cold start reveals more than a warm one.
• Steering: Should be smooth and responsive with no pulling to one side.
• Brakes: Should be firm, progressive and straight. No grinding, pulsing or vibration.
• Gearbox: All gears should engage smoothly. Listen for whining or crunching.
• Clutch: Should bite at a reasonable point, not right at the top of the pedal travel.
• Suspension: No clonking over bumps, no excessive body roll on corners.
• Engine: Should pull smoothly without hesitation, misfiring or excessive smoke.
• Exhaust: Blue smoke = oil burning. White smoke = head gasket. Black smoke = overfueling.
• Drive at least 15-20 minutes, including some dual carriageway if possible.

9. Negotiating the Price

Our MOT history data gives you powerful negotiating leverage:

• Use defect history: "I can see it's had recurring brake issues and a corrosion advisory — I'd want that reflected in the price."
• Cambelt due: "The cambelt hasn't been changed in 5 years — that's a £500 job I'll need to do straight away."
• High mileage: "It's averaging 14,000 miles a year which is above average — there'll be more wear on components."
• MOT expiry: "The MOT runs out next month. I'd want a fresh one before buying or an equivalent reduction."
• Compare listings: Use our comparison tool to show the seller you have other options with better histories.

10. Completing the Purchase

Before you hand over the money:

• Verify the V5C registration document — the seller's name and address should match
• Check the VIN (Vehicle Identification Number) on the V5C matches the one on the car (visible on the windscreen and door frame)
• Never pay a deposit to "hold" a car unless you're certain about the purchase
• For private sales, pay by bank transfer — not cash — so you have a record
• From a dealer, you have legal protections under the Consumer Rights Act 2015
• Get any verbal promises in writing
• Make sure the seller gives you: V5C, service history, spare key(s), MOT certificate, any warranties