13 Free Car Checks You Probably Didn't Know Existed

There is a strange asymmetry in how people buy used cars. They will spend hours comparing prices, reading reviews, watching walkaround videos on YouTube. Then when it comes to actually checking the specific car they are about to hand money over for, they do almost nothing.

Part of that is because the industry has conditioned people to think "car check" means one thing: a paid HPI-style history check. Finance, write-off, stolen. Important, yes. But it is one dimension of a much larger picture, and it is the only one that costs money.

Everything below is free. No account, no email address, no trial that quietly starts billing you. Just a registration number and a few seconds.

The Checks Most Buyers Already Know About

1. MOT history

This is the one most people have at least heard of. Every MOT test a car has been through since 2005 is stored by the DVSA and publicly accessible. Not just pass or fail, but every advisory, every defect, every dangerous item. The full record.

What most people miss is how to read it properly. An advisory for "slight play in a track rod end" at the last test is not just a note. It is a repair that is coming. It might be three months or twelve, but it is coming, and if you are the one who buys the car, you are the one who pays for it. A free MOT check puts the full timeline in front of you so you can see what is wearing and how quickly.

2. Mileage verification

Clocking is not a thing of the past. The National Mileage Register still flags roughly 1 in 16 cars with a mileage discrepancy. The simplest way to catch it is to look at the mileage recorded at each MOT test. If the numbers do not go consistently upwards, something has happened.

This is not just about outright fraud. Sometimes a dashboard is replaced and the mileage resets. Sometimes a car is imported with kilometres that get entered as miles. The mileage trail does not tell you why the number dropped, but it tells you that it did. That is enough to ask the right questions before you buy rather than after.

3. Number plate lookup

The basics. Make, model, colour, engine size, fuel type, year of manufacture, date of first registration. It sounds obvious, but it catches more problems than you might think. A car advertised as a 2018 that was first registered in 2017. A "2.0 diesel" that the DVLA has recorded as a 1.6. A colour that does not match what is in the listing. These are the discrepancies that make you ask further questions.

The Checks Most Buyers Do Not Think to Run

This is where it gets more interesting. The three checks above cover the ground that most careful buyers already know about. The next ten cover ground that almost nobody thinks to check, despite the data being freely available.

4. Tax status

You would be surprised how often a car is advertised as taxed when it is not, or listed as SORN when it is actually on the road. A free tax check shows the current status, when it expires, the tax band and the annual cost. If someone is selling a car with three months of tax left, that is a small saving. If they are selling one that has been SORN for two years, that raises questions about why it has been sitting.

5. ULEZ compliance

London's Ultra Low Emission Zone now covers the entire Greater London area. Other clean air zones are live in Birmingham, Bradford, Bristol, and Sheffield, with more coming. If you are buying a car to drive in or around any major UK city, you need to know whether it is compliant before you buy, not when the first penalty charge lands on your doormat.

The rules are not complicated but they are specific. Petrol cars generally need to meet Euro 4 (roughly 2006 onwards). Diesels need Euro 6 (roughly 2015 onwards). But "roughly" is doing a lot of work in that sentence. The actual standard depends on the engine, not the year. A free ULEZ check tells you definitively whether the specific car is compliant.

6. Emissions data

Related to ULEZ but broader. CO2 output, Euro standard, engine capacity, tax band. Useful if you are comparing two similar cars and want to know which one will cost more to tax, or if you are buying a company car and need to understand the BIK implications. Also useful for spotting cars that have been remapped. A car that the DVLA has recorded as producing 120g/km of CO2 but that is producing noticeably more on the road has probably been tuned.

7. Known faults

This is one of the most underused checks available. Every model has a failure profile. Some are excellent. Some have well-documented weak points. A Vauxhall Astra will eat suspension bushes. A BMW N47 diesel has a timing chain that runs at the back of the engine instead of the front, which turns a routine replacement into an engine-out job. A Ford 1.0 EcoBoost built before mid-2014 has a documented coolant hose issue that can cause catastrophic overheating.

None of this is secret information. It is all in the MOT data, the forums, the technical service bulletins. The problem is that it is scattered across dozens of sources and nobody pulls it together in one place against the specific car you are looking at. A free faults check does exactly that.

8. MOT failure rate

A model's aggregate MOT failure rate tells you something that no individual check can: how reliable this type of car actually is in the real world, across thousands of examples, over years of testing. Not what the manufacturer claims, not what the press launch reviews say, but what actually happens when these cars reach three, five, eight years old.

Some models hold up remarkably well. A Honda Jazz has one of the lowest failure rates of any car on UK roads. A Renault Scenic has one of the highest. If you are choosing between two cars at a similar price point, the model with a 15% lower MOT failure rate is, on average, going to cost you less in the years ahead.

9. Running costs

The purchase price is what you pay once. Running costs are what you pay every month for as long as you own the car. Tax, typical repair costs, common failure items and their price range, MOT pass rate. A car that costs £8,000 to buy but £2,400 a year to run is more expensive over three years than a car that costs £10,000 to buy but £1,200 a year to run. Obviously. But almost nobody does that maths before buying.

10. Car valuation

What is the car actually worth? Not what the seller is asking, not what Auto Trader says similar cars are listed for, but what comparable cars are actually priced at across the market right now. A free valuation based on live dealer listings gives you a realistic range. If the car you are looking at is priced above the top of that range, you either need to understand why or you need to negotiate.

11. Rarity check

How many of this exact model are registered in the UK? Is the number growing or declining? A car with 200,000 examples on the road will be easy to find parts for and cheap to insure. A car with 800 examples on the road might hold its value better, but parts availability and specialist knowledge become real considerations. Neither is better or worse, but they are different ownership propositions and you should know which one you are walking into.

12. Free car check (combined)

If you want everything in one go, a combined free car check pulls together the DVLA details, MOT history, mileage, tax, known faults and rarity data into a single result. It is the fastest way to get a complete picture of a car without paying anything. Think of it as the starting point. If something in the free check raises a question, you can then dig deeper with the individual tools above.

13. HPI alternative

The phrase "HPI check" has become a catch-all for any car history check, in the same way "Hoover" means vacuum cleaner regardless of brand. An HPI alternative gives you the same government-sourced data (MOT, mileage, tax, DVLA details) without the cost. What it does not include is finance, write-off, and stolen vehicle data, which sit in commercial databases that charge for access. For most casual checks, the free version covers more than enough ground. For a car you are seriously about to buy, the paid data is worth having too.

What Free Checks Do Not Cover

It is worth being honest about what free checks cannot tell you. Three things sit behind paid commercial databases and are not available from government sources:

• Outstanding finance. If the previous owner bought the car on HP or PCP and has not settled the agreement, the finance company has a legal claim on the car. This does not show up in any government database.
• Insurance write-off status. If the car has been written off by an insurer (Categories S, N, or the older A and B), that record sits with the Motor Insurers' Bureau. A car can be repaired after a Cat S write-off and returned to the road legally, but you should know about it before buying.
• Stolen vehicle markers. The Police National Computer holds stolen vehicle records. If you are buying from a private seller you have never met, this check has obvious value.

For a full picture that includes all three, a paid car history check fills those gaps. But the 13 free checks above cover a remarkable amount of ground, and for anyone in the early stages of browsing or shortlisting, they are more than enough to separate the cars worth viewing from the ones that are not.

A Practical Approach

If you are actively looking for a used car right now, here is a sensible way to use these tools without burning an entire afternoon on each listing.

When browsing listings: run the combined free car check on anything that catches your eye. Takes 30 seconds. If the mileage trail looks clean, the MOT history is not littered with advisories, and the tax checks out, keep it on the list.

When you have a shortlist of two or three: run the running costs and known faults checks on each. This is where the real differences between similar cars show up. Two Volkswagen Golfs at the same price and mileage can have very different cost profiles depending on the engine and transmission.

Before you go to view: run a paid check to cover finance, write-off, and stolen markers. And if the car has been through franchised dealers, check the service history. A full service history is worth hundreds on the sale price. A missing one raises questions that a walkaround alone cannot answer.

Thirteen checks sounds like a lot. In practice, most of them take under a minute each and you only need to run the full set on the car you are actually about to buy. For everything else, the combined check and a glance at the known faults will tell you whether it is worth your time.

Related reading

• Free Car Check UK: What You Actually Get (and What You Don't)
• The Real Cost of Buying a Used Car (It's Not the Asking Price)
• Car History Check UK: The Complete Guide
• Your Car History Check Is Missing Half the Picture

Frequently Asked Questions

What free car checks can I do with just a registration number?

Using a UK registration number, you can check MOT history, mileage records, tax status, ULEZ compliance, CO2 emissions, known model faults, MOT failure rates, running cost estimates, a market valuation, rarity data, and basic DVLA vehicle details. All of this comes from government sources and is available without paying or creating an account.

Are free car checks accurate?

Free checks that pull from DVLA and DVSA databases are as accurate as the government records themselves. MOT history, tax status, and vehicle details come straight from official sources. Model-level data like fault profiles and failure rates is derived from aggregate analysis of government MOT records. Free checks do not include finance, write-off, or stolen vehicle data, which require paid commercial databases.

What is the difference between a free car check and a paid HPI check?

A free check covers everything available from government sources: MOT history, mileage, tax, DVLA details, emissions and ULEZ compliance. A paid check adds data from commercial databases: outstanding finance, insurance write-off status, stolen vehicle markers, and plate change history. Both have their place. Free checks tell you about the car's condition. Paid checks tell you about its legal and financial status.

Can I check if a car has been clocked for free?

Yes. Every MOT test since 2005 records the car's mileage. By viewing the full MOT history, you can see the mileage at every test and spot discrepancies. A car showing 60,000 miles at its 2023 MOT and 45,000 miles at its 2024 MOT has had its odometer wound back. This data is free and comes directly from the DVSA.