The term vehicle reference number usually means the document reference number printed on your vehicle registration certificate (logbook). In the UK, this is the 11-digit number on the front of the V5C. It is not the same as your registration plate number or the VIN (chassis number). The physical number stamped on the vehicle itself is the VIN.
Which “reference number” do you need?
Several different numbers are commonly called a “vehicle reference number.” The table below shows the most common ones, where to find them, and what they are used for.
| Number | What it identifies | Where to find it | Typical use |
|---|---|---|---|
| Registration (plate) number | The vehicle, for public identification | Front and rear number plates; registration certificate | Everyday identification, parking, tolls |
| Document reference number (UK V5C, 11 digits) | That specific V5C document | Front page of the V5C logbook | Taxing the vehicle online, certain DVLA services |
| V11 tax reminder reference (16 digits) | That specific tax reminder notice | Front of the V11 reminder letter | Renewing vehicle tax online or at a Post Office |
| New keeper slip reference (V5C/2, 12 digits) | The new keeper supplement | Green V5C/2 slip given to buyer at point of sale | Taxing the vehicle before the full V5C arrives |
| VIN (17 characters, chassis number) | The physical vehicle | Windscreen base, door pillar plate, chassis frame, registration certificate | Insurance, recalls, parts ordering, ownership verification |
| Fleet/unit number | A vehicle within a company’s fleet | Painted on the cab or stored in the fleet management system | Internal tracking, maintenance scheduling |
| Insurance policy/reference number | Your insurance policy | Insurance certificate or schedule issued by your insurer | Claims, roadside checks, renewals |
Where to find the document reference number on a registration certificate
In the UK, the document reference number is printed on the front page of the V5C logbook. It is an 11-digit number and a new one is issued every time a new V5C is printed — for example, when the vehicle changes keeper. You will need it when taxing your vehicle through the DVLA’s online service and for certain other DVLA transactions.
Registration certificates in other EU and Nordic countries also carry a document reference number, but its position and format vary by country. If you are outside the UK, check the guidance published by your national vehicle registration authority to identify the correct field.
You generally cannot look up a document reference number online. If your registration document is lost or damaged, apply for a replacement through the authority that issued it — in the UK, that is the DVLA.
Is the reference number the same as the registration number?
No. The registration number is the plate number displayed on the front and rear of your vehicle and used for everyday identification. The document reference number identifies the registration certificate itself, not the vehicle. They are two separate numbers and serve different purposes.
Where to find the VIN on a truck or van
The VIN (Vehicle Identification Number) is a 17-character code that uniquely identifies the physical vehicle. On trucks and vans it is typically found in several locations:
- Base of the windscreen — visible from outside, on the dashboard edge below the glass.
- Door pillar or manufacturer’s plate — a metal plate on the driver’s door pillar or door frame, sometimes called the vehicle specification plate. This plate also shows permissible weights, engine details and other build data.
- Chassis frame — stamped directly onto the frame rail, usually visible from underneath or inside the engine bay.
- Registration certificate — on EU-harmonised certificates, the VIN appears in field E.
If you are searching for the vehicle specification plate, this is the manufacturer’s plate on the door pillar described above. It carries the VIN alongside weight ratings and other technical data, and is the authoritative source for the vehicle’s official build specification.
What is a vehicle unit number?
A vehicle unit number is an internal identifier assigned by a fleet operator, not an official government or manufacturer number. Fleets use unit numbers to track individual vehicles within their own systems. The number is typically painted or stickered on the cab door or bumper, and stored in the company’s fleet management software. It has no legal standing outside that organisation.
Which vehicle details you need when ordering truck or van accessories
When ordering cab-specific accessories — such as sun visors, bull bars, roof bars or front spoiler bars — the most important details are the vehicle’s make, model, cab type or variant, and year of first registration. Getting these right ensures the accessory is designed for your exact cab shape and mounting points.
Most of this information is on the registration certificate. EU-harmonised certificates typically show the make in field D.1, the type, variant and version in field D.2, and the date of first registration in field B. For some trucks, the cab type — for example, the roof height (low, medium or high roof) — may not appear on the registration certificate and may need confirming from the manufacturer’s plate on the door pillar, or from the original dealer documentation.
When contacting RST-Steel about fitment, sending the make, model, cab variant, year and any cab-height information gives the clearest picture. A photo of the relevant fields on your registration certificate (with any personal data covered) can also help avoid any ambiguity.
Browse accessories by vehicle type:
Frequently asked questions
Can I find my V5C reference number online?
No. The 11-digit document reference number is printed on the physical V5C logbook only. If you have lost your V5C, you will need to apply to the DVLA for a replacement document. The DVLA does not provide document reference numbers through an online lookup service.
Does the document reference number change?
Yes. A new document reference number is printed every time a new V5C is issued — for example, when a vehicle is sold and the keeper changes, or when you update your details with the DVLA. Each version of the V5C has its own unique 11-digit reference number.
What is a reference number for insurance?
An insurance reference number (or policy number) is issued by your insurer and identifies your specific insurance policy. It appears on your insurance certificate and schedule. It is separate from any vehicle registration document number. You will need it when making a claim or providing proof of insurance at a roadside check.
Is the VIN the same as the chassis number?
Effectively yes. The chassis number is an older term for the same unique vehicle identifier. Modern vehicles use the standardised 17-character VIN format. On older vehicles, the chassis number may be shorter or formatted differently, but both terms refer to the number stamped on the vehicle’s frame that uniquely identifies it.
What details do I need to order accessories for my truck?
You need the make, model, cab variant (including roof height if relevant), and year of first registration. These details are usually on the registration certificate and the manufacturer’s plate on the door pillar. Having these ready — or a photo of the relevant certificate fields — makes it straightforward to confirm which accessories fit your vehicle.
Need help finding the right accessory for your vehicle?
If you are unsure which accessory fits your truck or van, our team is happy to help you confirm compatibility. Contact us with your vehicle details, or submit a quote request and we will come back to you.
