Not every vehicle modification in Queensland needs a mod plate.

Some changes can be made without certification. Others need to be inspected and certified by an Approved Person.

What applies can depend on:

• your vehicle’s make, model and year

• what you want to change

• how the modification will be carried out

• the vehicle’s original specifications

• any existing modifications.

That’s why something that was okay on someone else’s vehicle may not necessarily be okay on yours.

What Vehicle Modifications May Need a Mod Plate?

Depending on the vehicle and the work being done, certification may be required for modifications involving:

• seats and seatbelts

• suspension and vehicle lifts

• GVM or other mass changes

• engines

• brakes

• steering

• body or chassis changes

• campervan and motorhome conversions.

This does not mean every change in these areas automatically needs a mod plate.

It means you need to check what applies to your particular vehicle and modification.

Do I Need a Mod Plate to Remove Seats?

This is a good example of why the answer is often “it depends.”

Removing seats may affect a vehicle’s seating capacity, and Queensland Transport and Main Roads (TMR) publishes specific information about removing seats and changing seating positions.

So even when a change seems simple, it is worth checking before starting the work.

Check First. Modify Second.

It can be much easier and cheaper to find out what is required before buying parts or carrying out the modification.

TMR provides free official information for Queensland vehicle owners:

Vehicle Modifications

https://www.tmr.qld.gov.au/safety/vehicle-standards-and-safety/vehicle-modifications

Vehicle Standards Information Sheets

https://www.publications.qld.gov.au/dataset/vehicle-standards-information

Queensland Vehicle Modification Codes

https://www.tmr.qld.gov.au/business-industry/accreditations/approved-person-scheme/vehicle-modification-codes

These links take you to official Queensland Government information.

Still Not Sure?

Sometimes you can read the rules and still be left wondering:

“But what does that mean for my vehicle?”

That’s when vehicle-specific advice may be needed.

If you contact us, have ready:

• vehicle make and model

• year

• VIN

• a short description of what you want to do

• clear photos of the vehicle and the area being modified.

Need help with your particular vehicle?

Submit your request via our online enquiry form.

Important Information

This information has been prepared independently by TechEng Queensland using information published by Queensland Transport and Main Roads.

It is a general plain-English guide only. It is not a TMR publication, does not imply TMR endorsement, and does not replace current TMR requirements or vehicle-specific engineering advice.

Already engineered interstate? So do you need a Queensland mod plate?

If you're bringing a modified vehicle into Queensland, you may assume that because the modifications were engineered or certified in another state or territory, nothing further is required.

That isn't necessarily the case.

Queensland Transport and Main Roads (TMR) advises that modifications performed and certified in another Australian jurisdiction are not automatically recognised in Queensland.

For most recreational modifications to light vehicles, the vehicle will need to be assessed and certified by a Queensland Approved Person before it can be registered in Queensland.

What happens to my interstate certification?

Keep your interstate engineering and certification documents. They may assist with the Queensland assessment, including:

• engineering reports and certificates

• modification approvals

• drawings or specifications

• component information

• photographs and details of the work performed

What does a Queensland Approved Person assess?

A Queensland Approved Person assesses the vehicle against the applicable requirements of the Queensland Road Vehicle Modification Handbook and relevant modification codes.

The Approved Person will need to determine:

• what modifications have been made

• which Queensland modification codes apply

• whether the vehicle complies with the applicable requirements

• whether further engineering information or changes are required

Where the modification complies and falls within the Approved Person's approved codes, it can be certified and the required Queensland modification plate attached.

Are there exceptions?

Yes. TMR has a process for considering recognition of interstate-certified modifications in limited circumstances, including certain disability-related modifications or modifications that provide a community benefit.

For other modifications, including recreational modifications, TMR advises that certification by a Queensland Approved Person is required before Queensland registration.

Buying a modified vehicle interstate?

Check the Queensland requirements before you buy. Find out:

• what has been modified

• how it was certified

• what engineering documentation comes with the vehicle

• whether the modifications can be certified in Queensland

Check First. Buy Second.

Need the modification reviewed?

TECHENG provides an Initial Engineering Review to establish the likely Queensland engineering and certification pathway.

David Turner RPEQ is a Queensland TMR Approved Person and can assess vehicle modifications within his approved modification codes and engineering scope.

Official Queensland Resources

TMR – Vehicle Modifications Includes TMR requirements for modifications performed and certified outside Queensland.

Queensland Light Vehicle Inspection Manual Queensland inspection requirements for light vehicles.

Queensland Road Vehicle Modification Handbook Queensland modification codes and certification requirements.

TMR – Approved Person Scheme Information about the role of Approved Persons in vehicle modification certification.

This information is general in nature and is not engineering advice. Requirements may vary depending on the vehicle and modification. Always refer to current Queensland TMR requirements.

Removing rear seats can create useful space in a 4WD or passenger vehicle. Whether you need a modification plate depends on whether the removal is temporary or permanent, and how it affects the vehicle.

Temporary or Permanent?

TMR’s guidance allows temporary removal of original quick-release seats without a modification plate. Temporary removal of bolt-in seats does not require Approved Person approval, provided it does not change the vehicle category.

Seats removed indefinitely, or with no expectation of being refitted, are considered a permanent change requiring certification by an Approved Person and a modification plate.

What Happens at a Safety Certificate Inspection?

TMR’s instruction says the vehicle must have its original seating configuration restored or a modification plate fitted covering the seating configuration presented.

This matters if you are preparing to sell or register a vehicle with seats missing.

Seats With Airbags

If airbags are built into the seats, contact the vehicle manufacturer before temporary or permanent removal to establish whether the change would adversely affect the restraint system.

Which Modification Code Applies?

Queensland lists LK1 - Seat and Seatbelt Installation/Removal among its approved light-vehicle modification codes. An Approved Person determines the applicable requirements for the particular change.

Check First. Modify Second.

Before removing seats, gather the vehicle make, model, year, current seating capacity and photographs. Explain which seats you intend to remove and whether they will be refitted.

If you need a vehicle-specific engineering assessment, contact TECHENG about a Preliminary Engineering Review. Certification remains subject to assessment and compliance with the applicable requirements.

Official Queensland Resources

• TMR — Permanent and Temporary Removal of Seats From Light Motor Vehicles

• Queensland Road Vehicle Modification Handbook

This information relates to light vehicles up to 4.5 tonnes GVM and is general in nature, not vehicle-specific engineering advice. Requirements depend on the vehicle and modification. Refer to current Queensland TMR requirements. This article is independently prepared by TECHENG and is not endorsed by TMR.

Lifting your 4WD or ute? Whether you need a modification plate depends on the vehicle, how much it is raised and whether the lift comes from suspension, larger tyres or body blocks.

When Is Certification Not Required?

Queensland’s LS9 and LS10 codes allow eligible vehicles in ADR categories MC, NA and NB1 to have a Basic Modification without certification, comprising:

• Up to 50mm suspension lift.

• Up to 25mm lift from larger tyres.

• Up to 75mm overall when combining the two.

The modification must meet the relevant code requirements and other applicable vehicle standards. These limits apply to vehicles with or without Electronic Stability Control (ESC).

Larger Tyres Count Towards the Lift

Tyre lift is half the increase in tyre diameter. For example, tyres with a diameter 50mm larger than the original add 25mm to the vehicle’s height.

Combined with a 50mm suspension lift, that produces a total lift of 75mm.

What About Body Lifts or Higher Lifts?

Body-block lifts require certification, even if the total lift is under 75mm.

Complex lifts require LS9 design certification and LS10 modification certification against that design. The codes allow:

• Up to 100mm suspension lift.

• Up to 25mm tyre lift.

• Up to 50mm body-block lift, reduced to 25mm if the suspension lift exceeds 75mm.

The combined lift must not exceed 150mm. Individual limits, applicable testing and other compliance requirements must also be met. ESC-equipped vehicles require evidence that the system continues to comply where required by the codes.

Being below 150mm does not automatically make a lift certifiable. Modifications outside the scope of LS9 and LS10 require specific TMR approval.

Check First. Modify Second.

Before buying a lift kit, gather your vehicle’s make, model, year, original and proposed tyre sizes, suspension-kit details and any existing modification certificates. Include photographs and details of any body lift.

Contact TECHENG about a Preliminary Engineering Review to assess the proposed combination. Certification remains subject to assessment and compliance with the applicable requirements.

Official Queensland Resources

• TMR — LS9 High Lift: Design Certification

• TMR — LS10 High Lift: Modification Certification

This information relates to eligible light vehicles in ADR categories MC, NA and NB1, up to 4.5 tonnes GVM. It is general in nature, not vehicle-specific engineering advice. Requirements depend on the vehicle and modification. Refer to current Queensland TMR requirements. This article is independently prepared by TECHENG and is not endorsed by TMR.

Thinking about fitting 35-inch tyres to your 4WD or ute? Whether they comply depends on your vehicle’s original tyre specifications, the increase in diameter and any other modifications.

“35-Inch” Is Not the Approval Rule

Queensland’s LS9 and LS10 codes allow eligible vehicles in ADR categories MC, NA and NB1 an increase in tyre diameter of up to 50mm within those codes, subject to their other requirements.

That is an increase from the vehicle’s original specifications - not a blanket allowance to fit 35-inch tyres.

Check the tyre placard and manufacturer’s specifications, then compare the diameter of the proposed tyres.

Tyres Also Increase Vehicle Height

The lift from larger tyres is half the increase in diameter. A tyre that is 50mm larger adds 25mm to the vehicle’s height.

For eligible vehicles, up to 25mm tyre lift combined with up to 50mm suspension lift can fall within the Basic Modification limits without LS9 or LS10 certification, provided all relevant requirements are met.

Will a Mod Plate Make Them Compliant?

A modification plate does not automatically approve any tyre size.

A tyre-diameter increase exceeding 50mm is outside the scope of LS9 and LS10. It requires consideration through TMR’s specific-approval process; approval should not be assumed.

Even within the diameter limit, tyre width, rim suitability, wheel track, clearance, mudguard coverage and speedometer accuracy must meet the applicable requirements.

Check First. Modify Second.

Before buying tyres, gather your vehicle’s make, model, year, a photograph of the tyre placard, proposed tyre and rim specifications, and details of any suspension or body lift.

Contact TECHENG about a Preliminary Engineering Review to assess the proposed combination. Certification remains subject to assessment and compliance with the applicable requirements.

Official Queensland Resources

• TMR — LS9 High Lift: Design Certification

• TMR — LS10 High Lift: Modification Certification

This information relates to eligible light vehicles in ADR categories MC, NA and NB1, up to 4.5 tonnes GVM. It is general in nature, not vehicle-specific engineering advice. Requirements depend on the vehicle and modification. Refer to current Queensland TMR requirements. This article is independently prepared by TECHENG and is not endorsed by TMR.