Motorbike VIN & Frame Number Check

What is a motorbike VIN (frame or chassis number)?

The Vehicle Identification Number (VIN) is the unique code stamped on a motorbike’s frame. You will also see it called the frame number or chassis number. No two modern bikes share a VIN, which makes it the most reliable way to tell whether the bike in front of you is the one described on the paperwork.

Where to find the VIN on a motorbike

• Steering headstock: the most common spot. Look at the frame tube behind the front forks, often on the right-hand side.
• Frame: on some bikes the number is stamped on a frame downtube, the swinging arm mount or near the footpeg bracket.
• Identification plate: some models carry a riveted plate with the VIN and approval details.
• V5C logbook: the VIN is printed on the document, usually labelled as the vehicle identification, chassis or frame number.

The engine number is separate. It is stamped on the crankcase and is also listed on the V5C. Check both.

Check the VIN matches the V5C and the bike

This is the single most useful check you can do yourself. Ask to see the V5C and compare the frame and engine numbers to the bike, with the seller present. If they do not match, or the numbers look damaged, re-stamped or covered up, walk away. The government’s guidance on checks when buying a used vehicle covers the V5C steps in detail.

Reading a 17-character VIN

Most bikes built since the early 1980s have a 17-character VIN with a standard layout:

Characters	What they usually tell you
1–3	World manufacturer identifier: who built the bike and where.
4–8	Vehicle descriptor: model, engine and body details, set by the manufacturer.
9	A check character used on some markets to validate the number.
10	Model year code, on bikes that follow the standard.
11	Assembly plant code.
12–17	Serial number of the individual bike.

Not every maker follows the same pattern, and older bikes have shorter frame numbers, so use the layout as a guide rather than a test.

VIN vs engine number vs registration number

• VIN or frame number: identifies the frame and stays with the bike for life.
• Engine number: identifies the engine, which can be replaced. A different engine number is not always a problem, but it should be explained and recorded.
• Registration number: the number plate, which can be transferred to a different vehicle. It is not a permanent identity.

Can I run a VIN check here?

No. Our bike check looks bikes up by registration number, and the lookup and the free pro report do not return the VIN or frame number. Use the registration check to compare make, model, colour and engine size with the advert, then match the VIN and engine number to the V5C yourself using the steps above.

Spotting a cloned or ringed bike

A cloned or ringed bike carries the identity of another, legitimate machine. No check on this site can detect that, so look for physical clues:

• Frame or engine numbers that look tampered with, re-stamped or ground down.
• A V5C that looks wrong, such as poor printing, missing watermark or smudged details.
• Numbers that do not match the paperwork, or a seller who will not let you inspect them.
• A bike that does not match its description, such as the wrong colour or engine size for its model and year. A reg check can help here, see the motorbike reg check.
• A price far below the market.

If you suspect a bike is stolen or cloned, read how to check if a motorbike is stolen or written off and contact the police.

Frequently asked questions