What VSB 14 Covers for Light Vehicle Modifications

Vehicle Standards Bulletin 14 (VSB 14) is the National Code of Practice for Light Vehicle Construction and Modification. It provides technical requirements for many changes to vehicles with a Gross Vehicle Mass (GVM) not exceeding 4.5 tonnes.

VSB 14 is not a single national approval scheme. Each state and territory controls who may certify a modification, what documents are issued and how the vehicle's registration record is updated.

What VSB 14 does—and does not do

VSB 14 helps determine whether a light-vehicle modification can meet relevant safety and Australian Design Rule requirements. It divides work into minor modifications, basic modifications without certification and modifications requiring certification.

It does not:

• authorise every modification described in the code in every jurisdiction;

• make an engineer automatically authorised to certify in every state or territory;

• replace registration-authority approval or inspection requirements; or

• guarantee that an interstate certificate will be accepted without further checks.

The code should be read together with the requirements of the jurisdiction where the vehicle is or will be registered.

What types of modification are covered?

VSB 14 contains sections for:

• engines and transmissions;

• brakes;

• body and chassis;

• seating and occupant protection;

• motorcycles and three-wheeled vehicles;

• fuel systems;

• Australian Design Rule compliance and individually constructed vehicles;

• tyres, rims, suspension and steering;

• test procedures; and

• alternative power units.

Each section defines the scope of its modification codes. A build involving suspension, brakes, seating and chassis work may require assessment under several sections.

Minor, basic and certified modifications

Minor modifications are listed changes that do not require reference to a registration authority when completed within the stated conditions.

Basic modifications can be completed without formal certification only when they remain within the limits and technical requirements stated in the relevant section and jurisdictional rules.

Certified modifications can materially affect safety, strength, structural integrity, handling or compliance and require assessment by an appropriately authorised signatory.

The category depends on the exact design, not simply the name of the accessory. For example, a standard bolt-on component may be treated differently from an installation that changes structure, steering geometry or occupant protection.

Does VSB 14 govern every GVM upgrade?

Not by itself. A light-vehicle GVM increase is a vehicle-rating change whose availability and approval pathway vary between jurisdictions and between pre-registration and post-registration vehicles.

Before first supply, an approved Second Stage of Manufacture pathway may change the GVM under the Commonwealth Road Vehicle Standards framework.

After registration, the state or territory authority controls the pathway. Some jurisdictions publish specific GVM codes or type-approval arrangements. Do not assume that fitting an SSM suspension kit after registration automatically changes the registered GVM.

A GVM upgrade also does not automatically increase GCM, braked towing capacity or every axle rating.

Who can certify a VSB 14 modification?

The national code uses the general term signatory for a person accredited or recognised by a registration authority. The schemes and titles differ, including Approved Persons, licensed certifiers and recognised engineering signatories.

Authorisation is limited by jurisdiction and modification code. A qualified engineer is not necessarily authorised to issue the required certificate for every code or state.

Typical approval process

1. Identify the vehicle, registration jurisdiction and proposed changes.

2. Check whether each change is minor, basic or requires certification.

3. Confirm the applicable codes and the signatory's authority before work begins.

4. Develop the design and collect manufacturer and component evidence.

5. Complete installation with staged inspections where required.

6. Undertake the necessary inspection, measurements and tests.

7. Obtain the jurisdiction-specific certificate, plate, report or permit.

8. Complete any registration-authority inspection or record update.

The order may differ where prior approval is required.

Why jurisdictional differences matter

VSB 14 deliberately does not set the administrative process for the states and territories. Queensland supplements national material with its own modification code and Approved Person scheme. NSW uses the Vehicle Safety Compliance Certification Scheme. Victoria uses VASS. Other jurisdictions have their own signatory, inspection and documentation arrangements.

Owners transferring a modified vehicle interstate should confirm recognition with the receiving authority before purchase or transfer.

Official references

• Commonwealth: Vehicle Standards Bulletin 14

• Commonwealth: Road Vehicle Standards laws

• Commonwealth: Second Stage of Manufacture

Technical content reviewed 13 August 2026. Check the current VSB 14 documents and the registration authority for the vehicle's jurisdiction before beginning work.

KME Vehicle Engineering can assess whether a proposed modification needs engineering and identify the appropriate pathway. Learn about vehicle modification engineering.