How to Find the Chassis Number on a Car in the UK
If you are buying a used car in the UK, someone will eventually ask for the chassis number. Sellers say it, insurers ask for it, history checks run on it. Then you look at the logbook and it says “VIN” instead. So which one is it?
Both. On a modern car, the chassis number and the VIN are the same 17-character code. The UK just uses both words, often in the same sentence. Here is where to find it and how to check you have got the right one.
Chassis Number and VIN: Same Thing?
For any car built since the early 1980s, yes. The V5C logbook even labels the box “VIN / Chassis / Frame No.” so it covers all the names at once. If you want the wider picture of how other countries name it, see our reference on what a VIN is called around the world.
The exception is older cars. A classic from before the 17-character standard carries a shorter chassis number stamped by the maker, with no check digit and no encoded year. Our guide to decoding a pre-1981 VIN covers those.
Where to Find the Chassis Number
There are four places worth checking. A genuine car shows the same number in all of them.
| Location | What to look for |
|---|---|
| V5C logbook | The vehicle identification box, labelled VIN / Chassis / Frame No. |
| Base of the windscreen | A small plate you read from outside, through the glass. Often on the passenger side of right-hand-drive cars, though it varies. |
| Driver’s door frame | A label or plate on the door pillar or frame. |
| Under the bonnet | Stamped into the bulkhead, a chassis leg or the suspension mounting. |
The V5C is the easiest start. You do not even need to be near the car. If a seller sends you a photo of the number, you can compare it against the logbook later, which is exactly the check that catches problems.
Check It Matches Everywhere
This is the step people skip. Read the number on the windscreen plate, then on the door frame, then in the V5C. Every character should match.
A mismatch is a warning, not always a disaster, but you should not buy until it is explained. Altered or swapped plates are how cloned and cut-and-shut cars get passed on. Our article on how VIN cloning scams work explains what to watch for.
Also check the plates themselves. They should look factory-fitted, with no scratches, glue marks or rivets that do not belong.
Read What the Number Says
Once you have it, you can read a lot from the 17 characters. A UK-built car usually starts with S (the first letter for the United Kingdom), a German one with W. Paste the number into our VIN Decoder to see the country, maker and model year. For a full walk-through, see how to read a VIN.
One honest caveat. Our decoder and validator follow the North American standard, which includes a check digit in position nine. Plenty of European-built cars do not use it that way, so a UK car can fail that test and still be genuine. We explain why in how to decode a European import VIN.
Use the Number for Checks, Not Just Looking
The chassis number is what a paid history check runs on, so it is the thing to have in hand before you pay a deposit. The free gov.uk services work from the registration number instead. The vehicle enquiry service shows tax and MOT status, and the MOT history service lists past tests, mileage and advisories. Neither one tells you about outstanding finance or insurance write-offs, so a car that looks clean on gov.uk can still have a problem. If you want the details of what the number does and does not reveal, read what a VIN tells you.
Keep Reading
- What a VIN Is Called Around the World
- Where to Find Your VIN: Every Location
- How VIN Cloning Scams Work
- How to Decode a European Import VIN
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