PBS and Mass Limit Changes 2026: What NHVR’s New Rules Mean for Your Trailer
From 1 August 2026, national mass limits changed under the amended Heavy Vehicle National Law (HVNL). If you run a PBS combination, or your operation has ever relied on Concessional Mass Limits (CML), there are a few things worth understanding.
The short version: for most operators, nothing needs to happen. Your approvals stay valid, and in a lot of cases you get access to more mass without lifting a finger.
Here's what actually changed, what it means for PBS operators specifically, and where you might want to check in with your PBS assessor.
From 1 August 2026, General Mass Limits (GML) rose to the levels that previously applied under Concessional Mass Limits (CML), and the separate CML category was removed from the national Mass, Dimension and Loading Regulation. Operators who only held Mass Management Accreditation for CML access may no longer need it, but accreditation is still required for Higher Mass Limits (HML) and Performance Based Standards (PBS) combinations.
CML Is Gone. GML Absorbed It.
CML hasn't been renamed. It's been retired. From 1 August 2026, GML rose to match the mass levels that used to require CML, and the CML category no longer exists in the regulation at all.
For a standard tandem or tri-axle group, that means more tonnes at general access, with no permit application and no accreditation needed to get there.
Tandem axle group: 17 t GML
Tri-axle group: 21 t GML (up from 20 t)
Tri-axle group, HML: 22.5 t
General access combination length: up to 20 m, if requirements are met (up from 19 m)
Source: NHVR, Mass, Dimension and Loading Changes fact sheet, effective 1 August 2026.
Do You Still Need Accreditation?
If NHVAS Mass Management Accreditation was only sitting on your file to unlock CML mass, you may not need it anymore. But that only applies to general access GML.
Accreditation is still required if you're running:
Higher Mass Limits (HML)
A Performance Based Standards (PBS) combination, including split axle and quad axle configurations
Mass Management Accreditation itself is transitioning to a new model, Alternative Compliance Accreditation, as part of the broader shift from NHVAS to the new Heavy Vehicle Accreditation scheme under the amended HVNL. If your combination runs on PBS or HML, that transition is worth a call to your PBS assessor rather than assuming nothing's changed.
Your Existing Approval Is Still Valid
If you hold a Design Approval (DA) or Vehicle Approval (VA) issued before 1 August 2026 that references CML, you don't need to reapply. Any reference to CML in an existing approval is now read as GML, so your paperwork keeps working without an update.
The only reason to go back to the NHVR is if you want to increase your mass limits further, or your PBS assessor identifies a change worth making under the new rules.
Euro VI Gets a Bit More Room
Road trains with a Euro VI compliant prime mover picked up a steer axle concession from 1 August 2026, extending a concession that previously applied to other vehicle classes. Depending on tyre section width, the steer axle limit rises to 6.5 t or 7.0 t.
Tag trailer tow mass ratio conditions were also amended in the same update. Midland's current reference is a 1:1.3 tow mass ratio for a rigid truck towing a tag trailer (with the towing vehicle required to carry at least 20% of the combined axle mass limits), against a 1:1 cap for dog and pig trailers.
Why This Matters for PBS Operators
Midland Pty Ltd manufactures trailers at Parkes NSW and Kyneton VIC, including PBS combinations built to a customer's specific mass and access requirements. A mass limit change doesn't move your trailer's rating on its own, but it can change what's worth asking for on your next build, or whether your current Vehicle Approval still reflects the best access level available to you.
If you're planning a new PBS build, this is a good moment to talk to your assessor about whether the new GML settings change your ideal axle configuration before the design is locked in.
Frequently Asked Questions
Do I need to reapply for my PBS approval because of the August 2026 changes?
No. If your Design Approval or Vehicle Approval was issued before 1 August 2026 and references CML, that reference is now read as GML automatically. You only need to apply again if you want to increase your mass limits beyond what your current approval allows.
Is CML still a thing after August 2026?
No. CML has been removed from the national Mass, Dimension and Loading Regulation. General Mass Limits (GML) rose to the levels that previously required CML, so the same mass is now available without a separate CML category.
Do PBS operators still need NHVAS accreditation?
Yes. While operators who only needed accreditation for CML access may no longer require it, Mass Management Accreditation (transitioning to the new Alternative Compliance Accreditation model) is still required for Higher Mass Limits and PBS combinations, including split axle and quad axle configurations.
Talk to Midland
Midland Pty Ltd manufactures PBS combination trailers at Parkes NSW and Kyneton VIC, engineered from your brief to fit your mass and access requirements. If you're planning a PBS build and want to talk through what the new GML settings mean for your configuration, get in touch before you lock in your spec.
Related guides:
Heavy Vehicle Regulations Change This August: Here's What You Need To Know
Exploring 5 Significant Benefits of Performance-Based Standards (PBS) and High-Productivity Freight Vehicles in Australia
PBS Combination Trailers