Key takeaway: Buying a used car without proper checks is one of the most expensive mistakes you can make. Some used cars carry hidden history (outstanding finance, a mileage discrepancy, a write-off record, or a stolen marker). A thorough pre-purchase process protects you from costly surprises and strengthens your negotiating position.
The UK used car market is massive: over 7 million used cars change hands every year (7.8 million in 2025, according to the SMMT). Most transactions go smoothly, but a significant minority result in buyers discovering problems they could have avoided with better preparation. This checklist covers every step, from initial online research through to final paperwork.
Start with a free check using our car cost tool. Enter the registration number to see the car's full MOT history, mileage verification, and predicted running costs. This takes 10 seconds and gives you a solid foundation before you even visit the car.
Stage 1: Online Checks (Before You Visit)
Before driving across town to see a car, do these checks from your phone or computer:
1. MOT History Check
The DVSA makes MOT history publicly available. You can view it through our free tool or directly on gov.uk. What to look for: To see how the car's make compares, our 2025 MOT failure rates by car brand rank first-MOT and 10-year fail rates from 33.2 million tests.
- Mileage consistency: Compare the recorded mileage at each MOT. The figures should increase steadily each year. Any sudden drops or large gaps between tests are red flags for mileage tampering (clocking).
- Failure patterns: Recurring failures in the same category (e.g. suspension every year) suggest an underlying structural issue or a car that is driven hard.
- Advisory trends: Advisories that appear and then disappear without time for repair may indicate the car was tested at a lenient station.
- Gaps in testing: A car that has missed one or more years of MOT testing may have been off the road (SORN) or abroad. Ask the seller to explain any gaps.
- Check for safety recalls. A recent MOT pass does not mean recall work has been done. Our free report shows DVSA's recall status for the car and the recalls DVSA lists for its model, with the fix. Recall repairs are usually free at a franchised dealer, so ask the seller to book any outstanding one before you pay.
2. Vehicle Tax and SORN Status
Check on gov.uk that the car is currently taxed. An untaxed car cannot legally be driven on public roads (except to a pre-booked MOT). If the car is on SORN, you will need to tax it before driving it home.
3. Running Cost Estimate
Before committing to a viewing, check what the car will cost you to run. Our tool shows the road tax band, estimated fuel costs, and predicted repair bills based on the car's MOT history. A car that looks cheap to buy can be expensive to own.
4. Market Value Check
Research the car's market value using AutoTrader, Cazoo, and similar platforms. Search for the same make, model, year, and approximate mileage to see what comparable cars are selling for. If the car you are looking at is significantly cheaper than market value, there may be a reason.