A camper trailer payload claim is verifiable only when it identifies the exact trailer configuration, the Aggregate Trailer Mass (ATM), the tare mass and the date or document revision behind the figures. Check that arithmetic against the physical vehicle plate and the Register of Approved Vehicles (RAV), then weigh the trailer in the condition you actually want to use it.

The result is two different answers. The documents establish the manufacturer’s rated load-carrying figure. A weighing establishes the trailer’s current mass. Neither answer alone proves that the trailer, tow vehicle, axles and components will remain within every applicable limit on a trip.

How to verify a camper trailer payload claim

Use four checks, in this order:

Check Evidence What it establishes
Define the claim Dated brochure, specification sheet or written quotation The model, variant, options and payload figure being offered
Reconcile the ratings ATM and tare for that exact configuration Whether the stated payload equals the difference between the two published values
Match the official records VIN, vehicle plate and RAV result Whether the mandatory mass values agree for the individual trailer
Measure the current trailer Weighbridge ticket with the load state recorded The actual mass of the trailer in that measured condition

Do not collapse the four rows into a single number. A brochure may describe a standard model while the trailer for sale has factory options, dealer-fitted equipment or a later specification revision. A plate and RAV record identify an individual vehicle, but they do not update themselves when accessories are added after its recorded tare was set. A weighbridge measures mass; it does not assign ATM or GTM ratings.

Start by defining exactly what “payload” means

Vehicle Standards Bulletin 1 (VSB1) Revision 6 says that ATM minus tare mass equals the maximum load the trailer can carry. In the same document, ATM and Gross Trailer Mass (GTM) are manufacturer-specified ratings, not values measured on a weighbridge.

That makes the first calculation simple, but the evidence behind it matters:

Published load-carrying figure = published ATM − published tare

Write down all three numbers from the same source revision. Record the units and whether the seller uses “payload”, “load carrying capacity”, “carrying capacity” or another term. If the advertised payload does not equal the advertised ATM minus tare, ask the manufacturer to explain the calculation in writing before treating either number as reliable.

Also confirm that “tare” refers to trailer tare mass rather than an informal “dry”, “base” or “starting” weight. VSB1 defines trailer tare as the total unladen mass, including the mass through the tyres and coupling, with standard equipment and fitted options in the ready-for-service configuration at the time of RAV entry. Its definition excludes water and wastewater tanks from the fluid reservoirs filled to nominal capacity for a caravan.

Those details are why a bare payload headline cannot show what you can pack. Our guide to ATM minus tare and actual camper trailer payload explains the mass calculation; this article deals with proving which figures belong in it.

Freeze the model, configuration and date

Save the page or PDF that contains the claim rather than keeping only a screenshot of the number. The surrounding qualifications may identify a model year, body length, axle arrangement, standard equipment or a note that specifications can change.

Build a configuration list from the written quotation or order form:

  • exact model and variant;
  • VIN, if the individual trailer has already been built;
  • standard equipment shown in the cited specification;
  • factory options fitted before delivery;
  • dealer-fitted accessories;
  • batteries, solar equipment, awnings, spare wheels and storage boxes;
  • water and waste-tank capacities;
  • gas cylinders and whether the claim assumes them full or empty;
  • racks, holders or mounts intended to carry separate equipment; and
  • document title, revision and access date.

Then ask one direct question: which of these items were installed when the stated tare was established?

“Standard” and “included in the sale” do not answer that question. An item can be part of the retail package yet be installed after the recorded tare configuration. Conversely, an option can already be included in the tare of an individually configured trailer. Count only what the documents support.

The ACCC’s general guidance says product claims should be accurate, truthful and based on reasonable grounds. It applies that principle across advertising, websites, quotations, packaging and information provided by staff. Keeping the claim and configuration together makes any later question specific: it identifies the representation, the vehicle and the evidence needed to check it.

Check ATM and tare against the vehicle plate

VSB1 says every trailer must carry a durable, permanently attached vehicle plate. The mandatory information includes the manufacturer’s name or vehicle make, the Vehicle Identification Number (VIN), ATM, GTM and tare mass.

Photograph the whole plate square-on so the VIN and all three mass values remain legible. Do not record only ATM. A payload claim cannot be checked without tare, and the relationship between ATM and GTM is needed to avoid treating the load carried through the coupling as if it disappeared.

Compare the plate with the documents line by line:

Field Sales document Vehicle plate Difference or explanation
VIN or vehicle identifier
ATM
GTM
Tare
ATM minus tare
Configuration date or revision

If the plate subtraction differs from the brochure payload, that does not by itself establish why. The brochure may cover another variant or revision, or the individual vehicle may have a different recorded configuration. The correct next step is a written reconciliation from the approval holder or seller, not an assumption about which value is “close enough”.

Search the RAV using the VIN

The Department of Infrastructure’s RAV public search accepts a vehicle’s permanently marked VIN. The department describes the RAV as a publicly searchable database of vehicles provided in Australia under the Road Vehicle Standards Act 2018.

Its RAV guide says trailers require both a digital RAV record and a physical vehicle plate. VSB1 states that the mandatory plate details must match those entered on the RAV, and specifically lists ATM, GTM and tare among those details.

Use the VIN from the trailer itself, not a VIN copied from an undated email. Save the result with the access date and compare:

  1. VIN on the trailer, plate and RAV result;
  2. make and other identifying information;
  3. ATM;
  4. GTM; and
  5. tare mass.

A matching RAV entry supports the identity and recorded ratings. It is not a weigh ticket, a packing allowance or proof that later accessories are included in tare. The RAV search also carries a departmental disclaimer about the timeliness and accuracy of results, so preserve the result and raise a discrepancy rather than silently substituting another figure.

For the full search process, see our separate guide to checking a camper trailer on the RAV. The trailer vehicle-plate guide covers plate construction and mandatory fields.

Reconcile what VSB1 says the capacity should cover

Revision 6 added caravan-specific load-carrying guidance in August 2026. Section 13.2.5 says capacity should allow the caravan to serve its intended purpose while remaining within the manufacturer’s GTM and ATM. It identifies three groups:

  • supplied equipment and the mass of fluids and gas at full capacity;
  • equipment not supplied but intended to be fitted because a feature has been provided, such as loaded jerry-can holders or a bike rack with bikes; and
  • personal effects, using 50 kg for each of the first two sleeping berths and 10 kg for each additional berth.

This is a design-evidence check, not extra weight above ATM. Ask the manufacturer for a capacity worksheet showing how those groups fit inside the stated load-carrying figure. If an item was already included in tare, it should not be deducted from the available figure a second time. If it was excluded from tare but will be carried, its mass consumes actual capacity.

The August guidance is also classification-specific. It appears in VSB1’s caravan section. Confirm the trailer’s category in the approval material instead of assuming that every product marketed as a camper has the same regulatory classification.

Our explainer on the VSB1 Revision 6 load-capacity changes examines the new section and its stated boundaries.

Weigh the trailer in a defined condition

Once the documentary figures reconcile, measure the trailer that will be used. The National Measurement Institute (NMI) says public weighbridges are open for public use, usually for a charge. Its national page lists licensed locations by state and territory.

NMI describes direct weighing of the entire vehicle in one weighing as the most accurate method and says it should be the preferred approach. End-and-end weighing is available when a vehicle does not fit, but the weighbridge must be approved for that method. A weighbridge can also record axles or axle groups separately.

Before attending, ask the operator whether the platform and procedure suit a coupled combination and an uncoupled trailer, and whether the intended axle measurements are available. Do not unhitch on a platform unless the operator confirms the procedure is permitted and safe.

Record the state of the trailer at the time of every measurement:

  • fresh, grey and black water levels;
  • gas-cylinder contents;
  • batteries and permanently fitted accessories;
  • food, luggage, tools and recovery equipment;
  • bikes, jerry cans and external cargo;
  • whether the trailer was coupled or uncoupled; and
  • occupants and load in the tow vehicle for combination measurements.

NMI says a public weighing is recorded on a measurement ticket. Depending on the weighing, the ticket can include gross mass, tare mass and net mass. Keep the original ticket with the configuration notes; the notes explain what the measured number represents.

Do not relabel a weighbridge’s “tare” line as the manufacturer’s recorded trailer tare without checking the conditions. Trade-measurement terminology on a ticket can describe the mass before a load is added, while VSB1 defines trailer tare by a specific ready-for-service configuration at RAV entry. The words can look identical while answering different questions.

Calculate actual remaining mass without changing the ratings

For a complete trailer weighed uncoupled in its current condition:

Mass remaining to ATM = recorded ATM − measured complete trailer mass

That result is conditional on the measured load state. Add water, gas, food or equipment later and the remaining amount changes. It is not a new manufacturer rating and should not replace the ATM or tare recorded on the plate and RAV.

A complete-trailer result also does not prove compliance with GTM, axle, tyre, wheel, coupling or tow-vehicle limits. VSB1 distinguishes ATM—the total loaded trailer mass including the load through the coupling—from GTM, the loaded mass transmitted through the trailer tyres when coupled. Position changes can alter those component loads even when total trailer mass is unchanged.

Keep the payload audit separate from the tow-vehicle assessment. VSB1’s new capacity section expressly says caravan luggage requirements are additional to the towing vehicle’s own luggage and load-distribution requirements.

What to do when the figures disagree

Pause the payload conclusion and send the seller or manufacturer one table containing every conflicting value. Ask for a dated written response identifying:

  1. the correct ATM, GTM and tare for the VIN;
  2. the source and revision of each value;
  3. the exact equipment included when tare was established;
  4. whether the plate or RAV entry requires correction;
  5. how the advertised payload was calculated; and
  6. which full fluids, intended accessories and personal effects were allowed for.

Do not diagnose the cause from a photograph alone, and do not alter a plate or treat a seller’s email as a replacement for the official record. A missing explanation does not prove a particular breach or an unsafe trailer; it means the payload claim remains unresolved.

The ACCC says the first step after seeing a potentially false or misleading claim is to contact the business and explain the problem. The ACCC accepts reports but does not resolve individual disputes or provide legal advice. Keep the advertisement, quotation, order, photographs, RAV result, correspondence and weigh ticket if further consumer assistance is needed.

A payload evidence pack for the purchase file

A claim that survives this process should leave a short, auditable file:

  • the original dated sales claim;
  • the exact model, option and accessory schedule;
  • a clear vehicle-plate photograph;
  • the VIN-based RAV result;
  • the manufacturer’s written capacity worksheet or reconciliation;
  • the weighbridge ticket and load-state notes; and
  • a calculation sheet that never mixes values from different configurations.

This does not turn a buyer into an approval engineer, and it does not certify the trailer. It does make the limits of the claim visible. You can see whether the headline is supported by its own arithmetic, whether the individual trailer’s records agree and how much mass remains in the configuration actually measured.

Disclosure and scope

Camper News AU is edited by Gauthier T., who works with Breath Trailer. Breath Trailer had no role in this article, supplied no figures and received no favourable treatment. No manufacturer or model is scored, ranked or promoted here.

This is a document-based explainer, not a physical inspection, certification or legal opinion. Camper News AU checked the current VSB1 Revision 6, the RAV public search and guide, NMI weighbridge guidance and ACCC claims guidance on 7 September 2026. Where a particular trailer’s documents conflict, the unresolved facts should be taken to the approval holder, relevant authority or an appropriately qualified professional rather than filled with an estimate.