Is the chassis plate the same as the plating certificate?

No. The chassis plate is a fixed marker on the vehicle, while the plating certificate is the official document that mirrors the permitted weights. Both should align.

Can I rely on the plate if paperwork is unavailable?

For day-to-day checks, yes, but you should still keep the correct paperwork. In enforcement or administrative contexts, officers may ask to see the VTG certificate alongside the vehicle.

My site weights don’t match the plate — which do I follow?

Always follow the lowest applicable limit: site or operator rules, legal road limits, or the plated limits — whichever is lower.

VIN & Chassis Plate: Location and Meaning on Trailers

The Vehicle Identification Number (VIN) uniquely identifies every trailer. On Don-Bur chassis the VIN is permanently stamped into the offside front chassis I-beam, while 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, the stamping, plate and plating certificate provide full traceability and demonstrate compliance.

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 will use the VIN to confirm the correct weights, components and records for the vehicle in front of them.

Don-Bur body number: On Don-Bur builds, the last five digits of the VIN are the Don-Bur body number (our 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 hide the stamping. A torch and phone camera help.

2) Chassis / VIN plate (tamper-proof information plate)

Typical location: Nearside front chassis I-beam (riveted or bonded).
Shows: VIN (repeated), manufacturer details, type-approval number, tyre size and wheel-nut torque, headline dimensions, and the permitted weight data used for compliance checks.

3) Plating certificate / VTG paperwork

Document: The official certificate that mirrors the same weight limits shown on the plate.
Good practice: Keep a copy with the vehicle records and a digital copy accessible to drivers or the transport office.

What the chassis plate shows (field-by-field)

Exact layouts vary, but you will typically see:

Manufacturer & 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 (useful for site surveys and ferry bookings).
Year of build — the manufacturing year of the trailer.
Permitted weights (plating data):
- Max gross weight (GVW) — the maximum authorised mass of the trailer in operation.
- Max kingpin load — vertical load permitted at the fifth-wheel.
- Axle load limits — per-axle maxima (e.g., Axle 1/2/3).
- Axle group load — the permitted total for the axle set.

How to read the weight information

Use these definitions when planning loads and when presenting the vehicle for checks:

GVW (Gross Vehicle Weight): maximum operational mass of the trailer (unladen + load) as permitted by approval and regulations.
Kingpin load: vertical load transferred to the tractor via the fifth-wheel. Must not exceed the value on the plate or the tractor’s capacity.
Axle loads: maximum for each axle; do not exceed any single-axle value even if the group total is within limit.
Axle group load: combined permitted load for the axle set. This is often the most practical number for weighbridge checks.

Note: Legal road limits, site restrictions and ferry/operator rules may impose lower operational caps than the plate allows. Always observe the lowest applicable limit.

Quick reference: common look-ups

Finding the VIN fast: Offside front I-beam (stamped); if obscured, use the nearside plate to read the VIN, then clean and confirm the stamping.
Ordering parts or documents: Quote the last five digits (Don-Bur body number) or the full VIN to speed up identification.
Checking weights before an MOT or RBT: Use the plate and VTG certificate to confirm GVW and axle loads; ensure the trailer is appropriately laden for testing.
Spec queries (tyres, dimensions): Read the plate, then cross-check with maintenance records or your build documentation.

If the plate is missing, damaged or unreadable

Use the stamped VIN on the offside I-beam as the primary identifier.
Check your VTG/plating certificate, RBT printouts and service documents for weight data.
Take clear photographs of the stamping and any remaining labels.
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 photos of the VIN stamping and chassis plate in the vehicle file.
Ensure maintenance providers record the full 17-character VIN on job cards and inspection sheets.
Before Roller Brake Tests, confirm the correct laden condition and record the weight used.
If graphics or paint work is planned, brief contractors to avoid covering the VIN stamping or plate.

Additional note on rigid bodywork

For rigid truck bodywork built by Don-Bur, there is no separate VIN stamping or Don-Bur chassis plate. The VIN and plating data are controlled by the truck manufacturer. Don-Bur fit a body number only, which is typically found on the offside edge of the front bulkhead. This number provides traceability for Don-Bur’s build records, documents and after-sales support.

Need help?

If you can’t locate the VIN stamping or need a replacement plate, please contact our team with photos and any available paperwork. We’ll confirm the identification and advise on next steps.