Australians selling items online are being urged to stay alert as scams targeting the booming second-hand market ramp up. Australia Post has issued a new warning about increasingly sophisticated fraud aimed at people using platforms such as Facebook Marketplace, as criminals try to cash in on the country’s growing online resale activity.

With Australians spending a record $18.9 billion on online marketplaces in the past year, scammers have more chances to insert themselves into private sales.

The scam typically starts when a buyer shows instant interest in an item. Instead of organising pick-up or paying directly, the “buyer” sends a link or QR code through Messenger, claiming it leads to an official “Australia Post courier service” that will manage payment and delivery. Clicking the link can redirect the seller to a convincing fake website designed to steal personal and financial information.

Australia Post chief information officer Adam Cartwright said these tactics are becoming harder to spot because they play on the convenience and familiarity of digital delivery services. He warned criminals are falsely presenting Australia Post as a middleman that collects money from buyers, transfers it to sellers, and organises delivery. “Be aware that Australia Post does not handle payments for buyers and does not have a courier service associated with Facebook Marketplace,” Mr Cartwright said.

Australia Post says more than 2500 Australians have reported these specific Facebook Marketplace scams so far this year, highlighting how quickly the problem is growing.

To reduce the risk, Australia Post says the official AusPost app is the safest way to track real deliveries, using secure push notifications rather than texts or emails that can be easily faked. It also reminded customers it will never ask for passwords, credit card numbers, or bank details over the phone, by text, or via email.

If a buyer insists you must click a link to “verify” payment or arrange a courier, it is almost certainly a scam.