About MOD/CHECK
A clearer way to check modified vehicles.
MOD/CHECK turns published vehicle-modification requirements into practical, source-linked pre-checks. It helps users understand which dimensional limits apply, how a result was reached and whether certification may be required.
Who it is for
Useful at the workshop, roadside or planning desk.
One transparent checking process can support different people looking at the same modification.
01
Owners & modifiers
Check a proposed or already-fitted change and understand which published limits and certification triggers may apply.
02
Authorised officers
Use a consistent dimensional pre-check with an understandable result and a traceable path back to the relevant published requirements.
03
Vehicle professionals
Identify likely certification triggers, missing information and the official source material relevant to a modification.
How it works
Guidance that shows its working.
Each ruleset records its jurisdiction, official source documents, version information and review date. Results explain the selected checks separately and identify requirements that still need inspection, further information or specialist assessment.
MOD/CHECK does not issue certification or replace an authorised officer’s judgement, a physical vehicle inspection, an official decision by the relevant road transport authority or an engineering assessment by an approved certifier.
Current coverage
New South Wales and Queensland.
New South Wales: system-specific assessments, a basic tyre diameter and width check, combined wheels and suspension checks, and multi-system Inspection Mode.
Queensland: selected checks across 11 vehicle systems, plus combined wheels and suspension. These cover wheels and tyres; suspension and ride height; engine and performance; driveline and steering; seats and occupant protection; braking systems; vehicle ratings and towing; lighting and visibility; body and chassis; mobility adaptations; motorcycles and trikes.
Each result identifies the selected requirements assessed. Other modifications, design suitability and the vehicle’s overall compliance may need separate assessment.
Review and corrections
How we look after the guidance
MOD/CHECK is an independent guidance service responsible for the content and operation of this website. Government authorities publish the requirements; an appropriately accredited certifier or Approved Person makes the relevant professional assessment. Referencing an official source does not imply government endorsement.
- Use the applicable source. Check the jurisdiction, vehicle scope, document edition and relevant requirements before adding or changing a calculation.
- Explain the result. Keep the reason, source, review date and limits with each finding. Missing evidence and a known defect are recorded separately.
- Check changes. Reproduce expected outcomes and keep earlier dated records intact. A source review or automated test is not an engineering approval.
- Keep limits visible. Where a current instruction or individual approval cannot be confirmed, refer the affected case for the appropriate advice.
Recent website updates
27 October 2026: current Queensland coverage descriptions, guide navigation and evidence preparation were brought into a consistent format. These presentation changes do not expand the approval scope of an assessment.
Help us correct a problem
Email info@modcheck.com.au with the page link, jurisdiction, assessment date or version, the finding you are querying and the official reference if available. Review your message before sending and remove registration plates, VINs, personal details and confidential records unless needed. Nothing is sent automatically.
A saved result reflects the guidance and entries at its recorded date. If the vehicle, evidence or requirements change, run a new assessment and keep both records.