Build or modify a light trailer

All trailers must comply with the applicable standards:

• Vehicle standards bulletin 9 - trailers manufactured before 1 July 1991 (PDF) (Please note that this is a historical document and is for reference only.)
• Vehicle standards bulletin 1 - trailers manufactured from 1 July 1991 to 30 June 2023 (PDF)
• Vehicle stanrds bulletin - trailers manufactured or registered for the first time in Australia from 1 July 2023 (PDF)

If you're unsure whether the modifications you are planning for a light trailer will affect its compliance to VSB1, you should consult with a vehicle assessment signatory scheme (VASS) signatory and obtain an approval letter confirming the compliance of the modifications.. 

The entire chassis or any part of a chassis with its vehicle identifier recorded on an interstate written-off vehicles register as a statutory write-off cannot be used to build or repair a trailer.

A trailer chassis can be constructed of second-hand parts/components provided they're not sourced from a statutory write-off vehicle.

Second-hand parts or accessories may be used to construct a trailer body. You must adhere to the design and construction standards and technical requirements detailed in VSB1. 

Changes to light trailer or caravan aggregate trailer mass

If you wish to change the aggregate trailer mass (ATM) from that which was originally specified by the trailer manufacturer, the following is required:

• a letter from a VASS signatory, or
• a letter from the trailer manufacturer confirming the ATM change
• change of vehicle details form (PDF)

Learn more about notifying VicRoads of changes and modifications.