Vehicle Assessment Signatory Scheme approval certificate

You will need a VASS approval certificate from a Signatory in the Vehicle Assessment Signatory Scheme (VASS) if your vehicle has been modified, imported or is an individually constructed vehicle.  

Vehicle modifications, such as those aimed at improving performance or appearance, may have an adverse effect on the vehicle’s safety or emissions performance. Government regulations require that all vehicle modifications must:

  • be carried out in accordance with guidelines issued by VicRoads, or
  • have VicRoads' specific approval. This applies to a vehicle that is already registered or when an application for registration is being made.

Vehicle standards information VSI8 - Guide to modifications for motor vehicles [PDF 280 Kb] provides guidelines covering many common modifications. Modifications carried out within the guidelines of VSI8 do not require specific approval, i.e. modifications are owner certified.

A vehicle modification beyond the guidelines in VSI8, require a VASS approval certificate. See below for examples of vehicle modifications that will require an approval certificate.

The Vehicle Assessment Signatory Scheme (VASS) is a scheme for the certification of modified, individually constructed vehicles and certain types of imported vehicles in Victoria.

An individual authorised by VicRoads to inspect, test and certify these vehicles is known as a VASS Signatory (referred to as an authorised vehicle inspector in the Road Safety (Vehicles) Regulations 2021) and is responsible to ensure all modified, individually constructed and certain imported vehicles meet standards for registration.

Once a VASS Signatory certifies a vehicle they will issue a VASS approval certificate and a blue modification plate that is attached to the vehicle

VASS Approval Certificate

A VASS Approval Certificate is required for:

  • all light vehicle modifications beyond the guidelines of:
    • VSI8 The guide to modifications to motor vehicles, or 
    • VSI33 VicRoads guidelines for modifications to vehicles operated under VicRoads Club Permit Scheme, or
    • VSI4 Summary of Registration requirements for motorcycles and mopeds
    • new Street Rods 
    • or Individually Constructed Vehicles (ICVs), including replica vehicles
    • some imported vehicles

If you're thinking about modifying, importing or building a vehicle, we recommend you discuss your plan with a VASS signatory Signatory before you start.

A VASS Approval Certificates issued to light vehicles are valid for 30 days from the date of issue. If the VASS Approval Certificate is for a modified heavy vehicle, the certificate does not expire.

Once submitted at a VicRoads Customer Service Centre, you  should retain a copy of the certificate in the vehicle for future reference.



Contact a VASS signatory for an appointment to get your vehicle inspected. 

For Light Vehicles

For Heavy Vehicles

Download the VASS Signatory Contact List - Heavy Vehicles [PDF 431 Kb]

For definitions of vehicle types go to Definitions of vehicles that may require a VASS Certificate to learn more.

What will the VASS Signatory do?

The VASS signatory will:

  • inspect the vehicle
  • ensure all work, including any modification, is correctly carried out
  • issue a VASS Approval Certificate that certifies the vehicle complies with the standards for registration.

Certificate validity

A VASS Approval Certificate is valid for 30 days from the date of issue. VicRoads will not accept a VASS Approval certificate more than 30 days from the date of issue for a light vehicle.

If the VASS Approval Certificate is for a modified heavy vehicle, the certificate does not expire.

Certificate cost

VicRoads does not regulate or specify the cost for the services of a VASS Signatory to issue a VASS approval certificate.

The cost for the services provided by a VASS Signatory will be dependent on the amount of work involved in the inspection and testing of your vehicle and will need to be discussed and arranged between yourself and the VASS Signatory.

To ensure the VASS Signatory can provide you with an accurate quote for their services, you are encouraged to provide them with as much information as possible regarding your project during the consultation.

If you need to register your vehicle after obtaining your VASS approval certificate you will need to:

  • follow steps outlined in registering your vehicle and
  • bring your valid VASS approval certificate along to your registration appointment.

If your vehicle is imported, check additional requirements to register your imported vehicle.

If your vehicle is registered and the modifications require a VASS approval certificate to be issued, you must notify VicRoads of the modifications before the registered vehicle can be used on a road or road related area.

A VASS approval certificate is required for modified vehicles if the modification is structural or affecting compliance with the standards for registration.

Refer to the VSI-8 Modification Guide within Vehicle Standards Information Sheets for detailed information.

Examples of modifications for which a approval certificate will be required include:

  • conversions of motor vehicles to motor homes
  • engine changes where the engine is not an option offered for that model by the vehicle manufacturer
  • installation of additional adult seats and seat belts
  • structural modifications e.g. conversion to a limousine, truck chassis extension
  • brake modifications (check VSI 8 - Modification guide for acceptable modifications not requiring an approval certificate)
  • left hand to right hand steering conversions
  • vehicles modified to provide wheelchair access and restraint
  • modifications or additions to heavy vehicles (check VSI 8 - Modification guide for acceptable modifications not requiring an approval certificate)
  • chassis replacement on a vehicle that has a separate chassis
  • vehicle has been modified to a tow truck.
Aggregate Trailer Mass (ATM)

The ATM of a trailer is the maximum it can weigh when fully loaded, as specified by the manufacturer.

Gross Vehicle Mass (GVM)

The GVM of a vehicle is the maximum it can weigh when fully loaded, as specified by the manufacturer.

Heavy Vehicle

Any motor vehicle with a GVM exceeding 4.5 tonnes and any trailer with an ATM exceeding 4.5 tonnes.

Imported Vehicle

A motor vehicle that has been brought into Australia in accordance with an option outlined in the National guidelines and requirements for importing a motor vehicle.

Individually Constructed Vehicle (ICV)

A vehicle that has been constructed by an individual for their own personal use, has not been adapted from or built off a production vehicle and has a GVM of 4.5 tonnes or less.

Light Vehicle

Any motor vehicle with a GVM of 4.5 tonnes or less and any trailer with an ATM of 4.5 tonnes or less.  Does not include Motor Cycles.


A motor vehicle with two wheels or a two wheeled motor vehicle with a sidecar attached to it that is supported by a third wheel.

Motorhome (or Campervan) 

A motor vehicle manufactured or modified to be used as living quarters and must contain specified equipment for accommodation, sleeping, cooking and storage.

Street Rod

A motor vehicle, or a replica of a motor vehicle, that has a body and frame that were built before 1949 and has been modified or built for safe road use in accordance with the National Street Rod Guidelines (NSRG).

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