Caravan ATM upgrades
A higher loaded limit for the van, approved under your state's rules.
An ATM (Aggregate Trailer Mass) upgrade raises the most the loaded van may weigh.
It does not change the limits in your car's owner's manual: the tow rating, towball limit and GCM (Gross Combination Mass). Your towbar and towball can set a lower limit.
The cost depends on the parts and sign-off your van needs. Ask for a written quote.
Published . 6 min read • Technical Guide
- In Queensland, an Approved Person signs it off.
- In NSW, the maker signs a letter, or a licensed certifier signs it off.
- In Victoria, a letter from the maker or a VASS (Vehicle Assessment Signatory Scheme) signatory.
- In WA, the transport department approves changes from the maker's specification.
- Your car's owner's manual limits stay the same.
General information from road authority pages and published figures. Not a compliance check. Weigh your loaded car and van before you tow.
Who signs it off in your state
On a van that is already registered, your state's road authority sets the steps. This is what each authority's own page said when we read it on 29 October 2026.
Queensland
- Who signs off
- An Approved Person: someone the Queensland Government approves to inspect and certify vehicle modifications.
- The code
- Under code LS14, an Approved Person can re-rate the ATM, the GTM (Gross Trailer Mass) or both, to the maker's specification. The evidence is a letter from the maker, or a comparison with another model from the same maker.
- Other changes
- Code LS12 covers other changes to a light trailer. The van must still meet Vehicle Standards Bulletin 1.
- Find one
- Search your suburb or town and code LS14.
New South Wales
- Who signs off
- The van's maker, with a letter of compliance signed by its chief engineer or compliance manager. A change outside the maker's instructions needs a VSCCS (Vehicle Safety Compliance Certification Scheme) licensed certifier.
- What happens next
- An adjustment of records inspection at an inspection station follows, because the change affects the registration details.
- Good to know
- If nobody can tell who made the van, the maker's letter route is not available.
Victoria
- Who signs off
- A VASS (Vehicle Assessment Signatory Scheme) signatory, or the van's maker, by letter.
- What you send
- The letter, with the change of vehicle details form.
Western Australia
WA's page on modifying a light trailer or caravan says:
- Who approves
- The Department of Transport and Major Infrastructure's Vehicle Safety and Standards section, for a van changed from the maker's specification.
- What you send
- An original letter from the maker specifying the modifications and confirming the van still meets the vehicle standards, or the online vehicle modifications form.
- What happens next
- Once the department approves it, the van needs a full vehicle inspection.
In South Australia, the Department for Infrastructure and Transport lists the engineering signatories it recognises, by field of work. Trailer and caravan ATM upgrades are among the listed fields. The department's light vehicle engineering signatories page has the list.
In Tasmania, the ACT and the Northern Territory, ask your road authority about an ATM change before you pay for work.
It raises the most the loaded van may weigh
The ATM is on the van's plate, with the GTM (Gross Trailer Mass) and the tare. The ATM minus the tare is the most the van can carry: water, gas, food and gear.
A higher ATM raises that figure. Parts added for the upgrade add to the tare. Until the change is signed off and your state's steps are done, use the figures on the plate.
Our caravan payload guide works through the subtraction.
Buying a new van
Some makers offer a higher ATM on particular ranges when you order. Ask the maker in writing which ATM and GTM the van's plate will show, before you pay a deposit.
The van must still meet the trailer standard
Vehicle Standards Bulletin 1 is the national standard for trailers up to 4.5 tonnes. Some of its rules depend on the van's ratings, so a higher rating may bring these with it:
- •Brakes: the GTM sets these. Over 750kg GTM, the van needs brakes. Over 2,000kg GTM, brakes go on every wheel, with breakaway brakes that hold for 15 minutes.
- •Safety chains: one chain up to 2,500kg ATM and two above it. Over 3,500kg ATM, the chains must be Grade T.
- •Coupling: a 50mm ball coupling is rated 750kg, 2,000kg or 3,500kg ATM, and the rating is marked on it.
NSW's towing rules also say the loaded van must stay within the tyres' rated carrying capacity. The tyre placard shows the load rating.
The maker or the certifier decides what has to change on your van. Ask them to list it in the quote.
Check your car against the new figure
The limits in your car's owner's manual stay the same. If a GVM (Gross Vehicle Mass) or towing upgrade is fitted to your car, use its label and certificate. Check three of them against the van loaded to its new ATM:
- The car's braked tow rating, against the loaded van.
- The car's towball limit, against the loaded van's ball weight. More load in the van usually means more ball weight.
- The car's GCM, against the loaded car and van together.
Your towbar and towball can set a lower limit than the car, and the lowest limit applies. Check the labels on your towing gear too.
Questions to ask in writing
- •What will the new ATM and GTM be?
- •Who signs it off: the van's maker, or which certifier?
- •Which parts change, if any?
- •Will the van get a new plate or label?
- •What happens with the registration, and who lodges it?
- •What will the loaded ball weight be at the new ATM?
Common questions
What is a caravan ATM upgrade?
It raises the van's ATM (Aggregate Trailer Mass), the most the loaded van may weigh. On a registered van, your state's road authority sets who signs it off and what follows, such as an inspection.
How much does a caravan ATM upgrade cost?
The cost depends on the parts and sign-off your van needs. Ask for a written quote that names the parts, the new ATM and GTM (Gross Trailer Mass), and who will sign it off. Ask whether it covers your state's next step, such as an inspection.
Does an ATM upgrade increase my towing capacity?
It does not change the limits in your car's owner's manual: the tow rating, towball limit and GCM (Gross Combination Mass). Use those figures. If your car has a GVM (Gross Vehicle Mass), GCM or towing upgrade, use its label and certificate. Your towbar and towball can set a lower limit, and the lowest limit applies.
Can any caravan get an ATM upgrade?
It depends on the van and the state. In Queensland, under code LS14, an Approved Person can re-rate a van to its maker's own specification. In NSW, the maker's letter route needs a known maker. In Queensland, the upgraded van must still meet Vehicle Standards Bulletin 1. Ask the van's maker first.
Who certifies a caravan ATM upgrade in Queensland?
An Approved Person: someone the Queensland Government approves to inspect and certify vehicle modifications. Under code LS14, an Approved Person can re-rate a van's ATM to the maker's specification. On the Queensland Government's find an approved person page, search your suburb or town and code LS14. If nothing shows, try a nearby suburb or your region.