VRM and VIN

Almost every endpoint identifies a vehicle by one of two values: its VRM or its VIN. Pass whichever you hold as a vrm or vin, either as a query parameter or in the request body, depending on the endpoint.

VRM

The VRM (Vehicle Registration Mark) is the number plate. It is the most common identifier in trade and insurance work because it is what is on the glass and what a customer reads out.

A VRM is not a permanent identifier. When a plate is moved (a cherished transfer of a private registration), there can be a delay before the new plate maps to the correct vehicle, typically a week or two while the change works through. If you look up a vehicle in that window you may get the previous vehicle, or no match. When you need a stable identifier, use the VIN.

VIN

The VIN (Vehicle Identification Number) is the 17 character identifier stamped on the chassis. It does not change, so it is the reliable choice when you need to match a vehicle consistently over time.

If you have a VRM and need the VIN, use VRM to VIN.