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Vehicle Modification Certification Requirements by State and Territory

The Australian Design Rules are national. Certifying your modification isn't: the scheme you deal with changes with the state or territory you're in, and so do the name for it, the qualifications your certifier needs, the paperwork and the level of government involvement.

What you'll read here applies to light vehicles, meaning a Gross Vehicle Mass of 4,500 kg or less. If yours is heavier, it sits with the National Heavy Vehicle Regulator (NHVR).

National overview

Where you are Scheme you'll deal with Who signs it off Authority
NSW VSCCS Licensed Certifier Transport for NSW
VIC VASS VASS Signatory Transport Victoria / VicRoads
QLD Approved Person Scheme Approved Person Dept. of Transport and Main Roads
SA RES Scheme Recognised Engineering Signatory Dept. for Infrastructure and Transport
WA Direct approval Automotive Consultant Dept. of Transport and Major Infrastructure
TAS AVCAIS Approved Vehicle Certifier Dept. of State Growth
NT Approved Engineers Recognised Engineer Motor Vehicle Registry
ACT Engineering Signatories Recognised Engineering Signatory Access Canberra
Important: a modification certificate issued in one state isn't automatically accepted in another. If you're buying a modified vehicle interstate, or moving, check with the transport authority in the receiving state first. Don't assume your certification travels with you.

New South Wales

In NSW you go through the Vehicle Safety Compliance Certification Scheme (VSCCS). If your vehicle is significantly modified, individually constructed or one of certain imports, a VSCCS licensed certifier has to certify it.

The certifier you use holds at least a Certificate IV in a relevant discipline and carries $20 million public liability and $5 million professional indemnity insurance. Each one is authorised for specific licence categories, so check the category covers your work. Your certificate comes through electronically and doesn't expire. If you're holding an old ECS certificate, it's no longer accepted.

Authority: Transport for NSW
Reference: Modified and non-standard vehicles (NSW Gov)
Find a certifier: VSCCS Certifier Search (Service NSW)

Victoria

In Victoria you work through the Vehicle Assessment Signatory Scheme (VASS). Touch an applicable ADR, structural integrity, a safety system, handling or emissions and you'll need a VASS approval certificate.

The signatory who signs your certificate holds a four-year engineering degree and is eligible for professional engineer registration. On a light vehicle the certificate is valid for 30 days, so line up your inspection. Some minor modifications are exempted under VSI 8.

Authority: Transport Victoria / VicRoads
Reference: VSI 8: Guide to Modifications (Transport Victoria)
Find a signatory: VASS Signatory Contact List

Queensland

In Queensland you go through the Approved Person Scheme, run by TMR. Your modification is sorted into Minor, Basic, Complex or Specific. Only a Complex modification needs certification by an Approved Person. If yours is a Specific modification, TMR has to approve it directly.

Certification from another state doesn't carry over here. If you hold an interstate certificate, it has to be re-certified by a QLD Approved Person.

Authority: Dept. of Transport and Main Roads
Reference: Vehicle Modifications (TMR)
Find an Approved Person: QLD Approved Person Search

South Australia

In South Australia your work is signed off through the Recognised Engineering Signatory (RES) scheme. For many modification types SA will also accept a VASS certificate you had issued in Victoria.

Authority: Dept. for Infrastructure and Transport
Reference: Vehicle Standards and Modifications (SA Gov)
Contact: 13 10 84 (Service SA)

Western Australia

In WA you apply to DTMI before a spanner goes near a complex modification. The order is fixed: submit the application, get approval in principle, do the work, get engineering certification, submit the report for final approval, then present the vehicle for government inspection.

Note: the WA government stays involved throughout. Start work before you have approval in principle and your modification may not be accepted.

Authority: Dept. of Transport and Major Infrastructure
Reference: Complex Light Vehicle Modifications (Transport WA)
Contact: 13 11 56

Tasmania

In Tasmania you work through the AVCAIS scheme, run by the Department of State Growth. Your Approved Vehicle Certifier operates out of an authorised inspection station.

Authority: Dept. of State Growth
Reference: Modification Inspections (Transport TAS)
Contact: avc@stategrowth.tas.gov.au or (03) 6166 3271

Northern Territory

In the NT you deal with approved engineers recognised by the Motor Vehicle Registry. In most cases the NT will recognise certification from an interstate engineer who's approved in their home jurisdiction.

Authority: Motor Vehicle Registry
Find an engineer: NT Approved Engineers
Contact: 13 23 11

Australian Capital Territory

In the ACT you use recognised engineering signatories. Your modification is assessed against VSB 14 and ACT-specific requirements. Access Canberra accepts signatories approved in other states and territories.

Authority: Access Canberra
Reference: Modified Light Vehicles (Access Canberra)
Contact: 13 22 81

Interstate transfers of modified vehicles

A Victorian VASS certificate you hold is generally accepted in SA, WA, NT, ACT and TAS. A NSW VSCCS certificate is generally NSW-specific. Queensland recognises no interstate certification automatically. WA wants you through its own government approval process.

If you're buying a modified vehicle from another state, or moving there, there's one call worth making first. Contact the transport authority in the receiving state and confirm what they'll accept before you travel.

You may want someone qualified to sign your work off: find a certifier in our automotive engineer directory.

Last updated: May 2026