Where are VIN stamps and chassis plates | What do they show?

The Vehicle Identification Number (VIN) uniquely identifies every trailer, while the chassis or VIN plate displays the key technical and legal information used for compliance. On Don-Bur chassis, the VIN is permanently stamped into the offside front chassis I-beam, and a tamper-proof chassis/VIN plate is typically fitted on the nearside front I-beam. The plate repeats the VIN and lists type-approval references, tyre specification, key dimensions and permitted weight (plating) data. Together with the plating certificate, these provide full traceability and confirm the trailer’s approved limits. The plate is sometimes informally referred to as a "ministry plate", although the correct term is the chassis or VIN plate.

What the VIN is and why it matters

The VIN is a 17-character code (letters and numbers) that serves as the legal identity of the vehicle. It links the physical trailer to its approval, service history and statutory documents. Enforcement officers and maintenance providers use the VIN to confirm the correct weights, components and records for the vehicle in front of them.

Don-Bur body number: The last five digits of the VIN form the Don-Bur body number (internal build reference). Quote either the full VIN or these last five digits when requesting parts, documents or service history.

Where to find identifiers on a Don-Bur trailer

1) VIN stamping (primary legal identifier)

• Location: Offside, front of the chassis, stamped into the main I-beam.
• Purpose: Permanent, tamper-resistant marking required by type approval.
• Tip: Clean the area; dirt, underseal or over-paint can obscure the stamping. A torch and phone camera help.

2) Chassis / VIN plate (information plate)

• Typical location: Nearside front chassis I-beam (riveted or bonded).
• Purpose: Displays the vehicle’s approved specification and permitted limits for compliance checks.
• Shows: VIN (repeated), manufacturer details, type-approval number, tyre size and wheel-nut torque, key dimensions, and permitted weight data.

3) Plating certificate / VTG paperwork

• Document: The official certificate that mirrors the same weight limits shown on the plate.
• Use: Required for records, testing and enforcement contexts.
• Good practice: Keep both physical and digital copies accessible.

What the chassis plate shows

Exact layouts vary, but you will typically see:

• Manufacturer and approval number — builder identity and type-approval reference.
• VIN — the 17-character vehicle identifier (last five digits = Don-Bur body number).
• Tyres — size and construction (e.g., 385/65 R 22.5).
• Wheel-nut torque — reference torque figure for wheel fixings.
• Dimensions — length, width and coupling-centre to rear.
• Year of build — manufacturing year of the trailer.
• Permitted weights (plating data):
  • Max gross weight (GVW) — maximum authorised mass of the trailer in operation.
  • Max kingpin load — vertical load permitted at the fifth-wheel.
  • Axle load limits — per-axle maxima.
  • Axle group load — permitted total for the axle set.

How to interpret the weight information

• GVW (Gross Vehicle Weight): Maximum operational mass of the trailer (unladen plus load).
• Kingpin load: Vertical load transferred to the tractor via the fifth-wheel. Must not exceed either the trailer or tractor limit.
• Axle loads: Maximum permitted load per axle; individual axle limits must not be exceeded.
• Axle group load: Combined permitted load for the axle set, commonly used for weighbridge checks.

Note: Legal road limits, site restrictions and operator rules may impose lower limits than those shown on the plate. Always follow the lowest applicable limit.

Quick reference

• Finding the VIN: Offside front I-beam (stamped). If obscured, read from the plate and confirm by cleaning the stamping.
• Ordering parts or documents: Quote the last five digits (Don-Bur body number) or the full VIN.
• Checking weights before MOT or RBT: Use the plate and VTG certificate to confirm limits and ensure correct test loading.
• Spec queries: Use plate data and cross-check with build or maintenance records.

If the plate is missing, damaged or unreadable

1. Use the stamped VIN on the offside I-beam as the primary identifier.
2. Check VTG/plating certificate, RBT printouts and service records.
3. Take clear photographs of the VIN stamping and any remaining labels.
4. Contact us with photos, registration (if applicable) and your fleet reference for advice on replacement or re-plating.

Good practice for records and inspections

• Keep clear photographs of VIN stamping and chassis plate on file.
• Record the full 17-character VIN on all maintenance and inspection documents.
• Confirm correct laden condition before Roller Brake Tests and record the test weight.
• Avoid covering VIN stamping or plates during painting or graphics work.

Additional note on rigid bodywork

For rigid truck bodywork, there is no separate Don-Bur VIN stamping or chassis plate. The VIN and plating data are defined by the truck manufacturer. Don-Bur provide a body number only, typically located on the offside edge of the front bulkhead, for internal traceability and support.

Related reading

• What documents are issued with new trailers?

Need help?

If you cannot locate the VIN stamping or need a replacement plate, contact our team with photos and available paperwork. Identification can be confirmed and next steps advised.