Is It Illegal to Sell a Car Privately With a Known Fault?

Selling a car privately with a fault you know about isn't automatically illegal in Australia, but lying about it can be. Private sales are generally governed by "buyer beware" rather than the consumer guarantees that cover dealer sales, so there's no blanket law forcing a private seller to list every flaw. What can get a seller into real trouble is actively misrepresenting the car's condition, or in some states, selling a registered vehicle without the safety certificate the law requires.

Here's how that actually breaks down.

This article is general information only and isn't legal advice. Laws and state roadworthy requirements change, and how they apply depends on your specific situation. If you're dealing with a dispute or need certainty before a sale, check the official links below or speak with a legal professional or your state's consumer affairs body.

Does Australian Consumer Law apply to a private car sale?

Mostly, no. The Australian Consumer Law's consumer guarantees, the ones that force dealers to repair, replace, or refund a faulty car, only apply to sales made "in trade or commerce." A one-off private sale between individuals generally doesn't meet that bar, even for a high-value vehicle. In one Federal Court case, the private sale of a $135,000 collectable car was found not to be "in trade or commerce," despite the car's value and the seller having occasionally hired it out.

Private sellers still have to guarantee a handful of things under the ACL regardless: that they actually own the car (clear title), that the buyer won't have their possession disturbed by someone else's claim on the vehicle, and that there's no undisclosed security interest, like outstanding finance, attached to it. Beyond that, the ACL's usual "acceptable quality" and "fit for purpose" guarantees don't apply to a private sale.

So what stops a seller lying about a fault?

Two things outside the ACL.

First, ordinary contract and common law still apply. If a seller actively lies about a known defect, rather than just staying quiet, that can amount to misrepresentation or fraud, and a buyer may have grounds for a civil claim. Genuinely staying silent about a fault the buyer never asked about sits in murkier legal territory than answering a direct question dishonestly. If a private seller is asked outright "has this had any accidents?" and says no despite knowing about one, that's a very different legal position to a seller simply not volunteering the information.

Second, some state fair trading rules go slightly further, particularly around statements made in advertising. Describing a car as being in "excellent condition" when the seller knows about a serious fault can shade into misleading conduct in some circumstances, even outside a strictly commercial sale, though this is genuinely a grey area and the details depend on the specific facts.

None of this is enforced automatically. Unlike a dealer dispute, which the ACCC or state fair trading bodies can pursue, a dispute between two private individuals over a car fault is a private civil matter. The buyer would generally need to pursue it themselves through a civil claim, not through a regulator.

Does a private seller have to provide a roadworthy certificate?

This is where the real legal risk sits for private sellers, and it varies significantly by state. A roadworthy or safety certificate confirms the vehicle met minimum safety standards on the day it was tested. It's not a full mechanical report, and it doesn't certify the car is fault-free, just that it passed a specific safety checklist.

Victoria: a current Roadworthy Certificate (RWC) is legally required before a registered vehicle can be sold privately and the registration transferred. It must be no more than 30 days old at the time of transfer. Official source: Transport Victoria, Roadworthy certificate.

Queensland: a current Safety Certificate is legally required for the private sale of a registered vehicle. The seller must provide it, and failing to do so carries a fine of more than $700. The buyer can't transfer the registration without one. Official source: Queensland Government, Safety certificates.

New South Wales: there's no separate requirement to hand over a safety inspection report at the point of sale itself. However, most light vehicles over five years old need a current safety inspection report (pink slip) before registration can be renewed or transferred, so in practice, a buyer will often need one shortly after purchase if the car falls into that category. Official source: Service NSW, Get a safety inspection report (pink slip).

Western Australia: no roadworthy certificate is required for a private sale. Inspections in WA are generally tied to registration renewal for vehicles over five years old, defect notices, or specific circumstances like imported or modified vehicles, not to the act of selling itself. Official source: Transport WA, Get a vehicle inspected.

South Australia: no roadworthy certificate is required for a private sale either. SA only requires a roadworthy inspection in specific circumstances, such as a modified vehicle, an interstate transfer, or a vehicle issued with a defect notice, not for an ordinary private sale. Official source: SA.GOV.AU, Roadworthy inspection.

ACT, NT and Tasmania each have their own variations again, generally falling somewhere between the Victorian/Queensland model and the WA/SA one. For a side-by-side comparison across every state and territory, the Federal Government's Office of Road Safety publishes an official summary: Rules for vehicle roadworthy standards in Australia (PDF).

Given how much this varies, and how often road rules get updated, always check the current requirement with your own state's transport authority (linked above) before selling, rather than relying on general advice like this article.

What actually happens if a private seller doesn't disclose a fault?

If it comes out that a seller lied outright about a known issue, the buyer's realistic options are a civil claim for misrepresentation, or in a state where a roadworthy certificate was legally required and wasn't provided, a fine for the seller and a stalled registration transfer for the buyer. There's no criminal offence for simply not mentioning a fault the buyer didn't ask about in a private sale.

That's exactly why a pre-purchase inspection and a PPSR check matter so much more in a private sale than a dealer sale. There's no statutory safety net waiting to catch a problem after the fact.

FAQ

Can I get in trouble for selling a car privately with a fault I didn't mention?

Not simply for staying silent, in most circumstances. Actively lying about a fault, especially in response to a direct question, is a different matter and can expose a seller to a misrepresentation claim.

Do I need a roadworthy certificate to sell my car privately?

It depends entirely on your state. Victoria and Queensland require one by law. NSW ties its safety inspection requirement to registration renewal rather than the sale itself. WA and SA don't require one at all for a private sale. Links to each state's official transport authority page are above, always check the current rule before selling.

Is a roadworthy certificate a guarantee the car has no faults?

No. It confirms the car met a specific safety checklist on the day of inspection. Non-safety items like air conditioning, infotainment, or general wear aren't covered.

What can a buyer actually do if a private seller lied about a fault?

Generally, pursue a civil claim for misrepresentation. Unlike a dealer dispute, this isn't something a regulator like the ACCC will typically pursue on the buyer's behalf.