Trailer and Caravan ATM Upgrade

It is illegal and potentially unsafe to use a trailer or caravan above it’s rated ATM, especially if the trailer structure is not capable of handling the additional load. An ATM upgrade will not only ensure that your trailer becomes compliant on the road, but also give you peace of mind knowing that it satisfies minimum structural requirements.

As engineers we certify modifications to trailers and caravans with an aggregate trailer mass (ATM) of up to 4500 kg in the Brisbane area. This normally involves an inspection of the trailer and detailed compliance checks in accordance with Queensland Transport requirements as specified in Modification Code LS12. If successful, and the trailer is structurally capable of handling the additional load, we will issue a blue modification plate. We can also assist and arrange with making structural alterations (drawbar or chassis reinforcements) where this may be required.

ATM upgrades Queensland Transport trailers caravans

Modifications covered by modification code LS12 include:

  • Rerating of a trailer or caravan’s ATM (ATM upgrade)
  • Suspension upgrades
  • Brakes (modifications or upgrades)
  • Tow couplings (new or modified installations)
  • Drawbars modifications/upgrades
  • Wheels (rims & tyres)
  • Trailer chassis modifications
  • Safety chain attachment point modifications

Typical situations where an ATM Upgrade may be required:

  • More load carrying capacity is required. It may be that the trailer/caravan is already over-loaded, or/and that additional load capacity is required.
  • Legal compliance – typically if a trailer is over-loaded, an ATM Upgrade may reinstate compliance (and avoid risking being fined).
  • Brakes have been fitted, modified or upgraded.
  • Wheel track width has changed by more than 50mm overall (25mm per side). Note that wheel track reductions are not permitted.
  • Wheel/rim offset has been changed by more than 12.5mm
  • Tyre diameter on a braked “on- road” trailer has been changed to more than 15mm larger, 26mm smaller or 30% wider.
  • Tyre diameter on an “off-road” trailer has been changed by more than 50mm larger, 26mm smaller or 50% wider.
  • Coupling replacements up to 3500kg ATM that result in an increase in drawbar length or if the coupling mounting position differs from the original.
  • All coupling replacements over 3500kg
  • Modifications/replacement of safety chain attachment points

For more information visit Queensland TMR Light Vehicle Modifications page.

Contact Us

For more information or to book an inspection, call or email us:
Mobile:   0408 112 604 (text message, SMS or voice message only)
Or use our contact form

Modification Codes

We are approved to certify modifications under the following 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 LC – Vehicle Controls

LC1: Dual-controls for Driver Trainer Vehicles (Design)

LC2: Dual-controls for Driver Trainer Vehicles (Modification)

LC3: Vehicle Controls for Persons with a Disability (Design)

LC4: Vehicle Controls for Persons with a Disability (Modification)

Section LG – Brakes

LG1: Brake System Conversion (Design)

LG2: Brake System Conversion Section

Section LH – Body and Chassis

LH1: Roof Conversion (Design)

LH2: Roof Conversion

LH3: Modified Wheelbase Conversion (Design)

LH4: Modified Wheelbase Conversion

LH5: Vehicle Construction (Design)

LH6: Vehicle Construction

LH7: Body/Chassis Variants Conversion

LH11: Campervan, Motorhome Conversion Section

Section LK – Seating and Occupant Protection

LK1: Seat and Seatbelt Installation/Removal

LK2: Seat and Anchorage Certification

LK6: Child Restraint Anchorage Installation

LK8: Construction and Installation of One-Off Roll-bars and Roll-cages by Individuals

LK9: Design and Manufacture of Commercial Aftermarket Roll-bars, Roll-cages and Other Types of Roll Over Protection Systems (ROPS)

LK10: Installation of Aftermarket Roll-bars, Roll-cages and ROPS Section

Section LM – Fuel Systems

LM1: Fuel Tank Installation Section

Section LO – Vehicle Standards Compliance

LO1: ADR Compliance

LO2: ICV Passenger Cars and Derivatives

LO3: Personally Imported Vehicle Compliance

LO4: ICV LEM1 Tricycle

LO5: ICV LEP1 Tricycle

LO7: ICV Motorcycle

Section LS – Tyres, Rims, Suspension and Steering

LS1: LHD Vehicle Steering Conversion (Design)

LS2: LHD Vehicle Steering Conversion

LS3: Front Suspension and Steering Modification (Design)

LS4: Front Suspension and Steering Modification

LS5: Rear Suspension Modification (Design)

LS6: Rear Suspension Modification

LS9: High Lift – 50mm – 125mm (Design) (More information in the QCOP)

LS10: High Lift – 50mm to 125mm Modification (More information in the QCOP)

LS11: GVM Increase (More information in the QCOP)

LS12: Light Trailer Modifications (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 LT – Test Procedures

LT1: Beam and Torsion Tests

LT2: Lane Change Maneuver Test

LT3: Exhaust Emissions – IM240 Test

LT4: Noise Test

Section LV – Alternative Power Units

LV1: Installation of Electric Drives in Motor Vehicles


Plus, we conduct modification approvals under the following Heavy Vehicle modification codes:

Section H – Chassis 

H5: Trailer chassis modifications

Section S – Vehicle Rating

S7: ATM/GTM re-rating

S12: ATM/GTM re-rating (design)


Contact Us

For more information or to book an inspection, call or email us:
Mobile:   0408 112 604 (text message, SMS or voice message only)
Or use our contact form

Deon van Deventer
TMR Approved Person MA3365