Modification Plates

Do I need a Modification Plate?

Modifications to light vehicles can be generally classified in 4 ways:

Minor modifications

Basic modifications

Modifications under a Code of Practice

Specific modifications.

Minor modifications 

Many minor modifications can be carried out without obtaining written approval.

Commonly, minor modifications involve the installation of an accessory (e.g. long range aerial, tow bars, roof racks etc) and provided the vehicle continues to meet the vehicle standards, do not require approval.

Basic modifications

Basic modifications are changes to a vehicle that are more significant than a minor modification, but not significant enough to require formal approval from an Approved Person or the Department of Transport and Main Roads.

Modifications under a Code of Practice 

Complex modifications such as engine upgrades, gearbox and rear axle changes, vehicle body modifications and steering and brake replacements are significant modifications to a vehicle and can seriously affect the safety of a vehicle if not performed properly.

Complex modifications to light vehicles must be certified by approved persons, providing the modifications have been performed in accordance with an approved code of practice.

Specific modifications 

Some owners require approval for vehicle modifications which may be outside the scope of the approved codes of practice and approval by an Approved Person and must be approved by the department.


Minor modification

Minor modification includes the fitting of optional equipment or alterations to a vehicle within manufacturer’s specifications that do not cause the vehicle to be non-compliant with heavy vehicle standards. Should clarification be required on whether a modification requires approval the NHVR will make a determination.

Examples include; additional lighting, aerials, air conditioning, alarm systems, plastic shields for lamps and windscreens, and manufacturer’s wheel and tyre options (that do not affect the Gross Vehicle Mass (GVM) or Gross Combination Mass (GCM) rating of the vehicle). These modifications do not require approval provided the vehicle continues to be within manufacturer’s specifications and comply with the heavy vehicle standards.

Modifications under the Code of Practice (Section 86 of the HVNL) – require approval by an AVE

These modifications are those outlined in the NHVR Code of Practice for the Approval of Heavy Vehicle Modifications (PDF, 433KB).

This includes complex modifications that can affect the safety of a vehicle if not performed properly. The modifications included in the Code are based on accepted vehicle engineering practices and the requirements of the heavy vehicle standards. The Code also supplements the recommendations of the original vehicle manufacturer in relation to vehicle modification techniques or standards and provides guidelines where manufacturer’s specifications do not exist.

For more information on light vehicle modifications please visit this website:
Modification Codes:

Light vehicle modification codes

Section LA – Engine  

  • LA1: Equivalent Engine Installation 
  • LA2: Performance Engine Installation 
  • LA3: Supercharger and Turbo Charger Installation 
  • LA4: Engine Modifications 

Section LB – Transmissions 

  • LB1: Transmission Substitution 
  • LB2: Rear Axle Substitution

Section LG – Brakes 

  • LG2: Brake System Conversion Section 

Section LH – Body and Chassis 

  • LH11: Campervan, Motorhome Conversion Section 

Section LK – Seating and Occupant Protection 

  • LK1: Seat and Seatbelt Installation/Removal 
  • LK6: Child Restraint Anchorage Installation 

Section LS – Tyres, Rims, Suspension and Steering

  • LS6: Rear Suspension Modification 
  • LS10: High Lift – Up to 150mm Modification Certification (More information in the QCOP
  • LS14: Re-rating of Aggregate Trailer Mass (ATM)/Gross Trailer Mass (GTM) of a Light Trailer to Manufacturer’s Specifications (More information in the QCOP)

Section LX – TMR Individual Approval

  • LX1: Modification of Light Vehicles to TMR individual approval. 

Heavy vehicle modification codes 

Section A – Engine and Ancillaries 

  • A1: Engine Substitution 
  • A2: Air Cleaner Substitution or Additional Fitment 
  • A3: Turbo Charger Installation 
  • A4: Exhaust System Alteration 
  • A5: Road Speed Limiter Installation

Section B – Transmission Modification 

  • B1: Transmission Substitution of Additional Fitment 

Section C – Tail Shaft Modification 

  • C1: Tail Shaft alterations    

Section D – Rear Axles

  • D1: Rear Axle Installation 
  • D2: Differential Substitution

Section E – Front Axle, Steering Wheels and Tyres

  • E1: Front Axle Installation 

Section F – Suspension Modifications 

  • F1: Suspension substitution     
  • F2: Trailer suspension modifications

Section G – Brakes

  • G1: Relocation of air brake components
  • G2: Installation of trailer braking controls 
  • G3: Trailer brake system upgrade 
  • G5: Fitting of auxiliary and endurance brakes
  • G6: Fitting of air operated accessories
  • G7: Brake system substitution/wheelbase extension
  • G8: Trailer brake system upgrade (design)

Section H – Chassis   

  • H4: Chassis alteration 
  • H5: Trailer chassis modifications

Section J – Body Mounting

  • J1: Body mounting

Section K – Cabin

  • K1: Seating capacity alteration, seat, seatbelt and anchorage alteratio

Section M – Fuel Systems 

  • M1: Fuel system alterations 

Section P – Tow Couplings

  • P1: Towbar and coupling installation other than fifth wheels and kingpins
  • P2: Fifth wheel and kingpin installation

Section S – Vehicle Rating 

  • S1: GVM/GCM re-rating (to S2 or S3 Approved Design or within Manufacturer’s Specifications) 
  • S7: ATM/GTM re-rating