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Why You Should Always Check the Serial Number Before Buying Second-Hand

Buying second-hand is a great way to save money and reduce waste — whether you are picking up a bicycle on Gumtree, a laptop on Facebook Marketplace, or a guitar from a mate of a mate. But there is a hidden risk that many buyers never consider: the item you are about to buy might be stolen.

The legal risk is real

In every Australian state and territory, receiving stolen property is a criminal offence — even if you had no idea the item was stolen. Under New South Wales law, for example, knowingly or recklessly dealing with stolen property carries a maximum penalty of up to ten years' imprisonment. In Victoria, the offence of handling stolen goods carries similar penalties under the Crimes Act 1958.

While courts generally consider whether you had reason to believe the item was stolen, ignorance is not always a reliable defence. If the price was suspiciously low, the seller could not provide a receipt, or the serial number had been scratched off, a court may find that a reasonable person should have been suspicious.

Beyond the legal risk, if police identify the item as stolen, it will be seized and returned to the rightful owner. You will lose the item and the money you paid for it, with very little chance of getting either back.

Where to find serial numbers on common items

Most valuable items have a serial number somewhere. Here is where to look for the most commonly traded second-hand goods:

  • Bicycles: Check the bottom bracket — the underside of the frame where the pedal cranks meet. Some manufacturers also stamp it on the head tube or rear dropout.
  • Laptops and computers: Look on the underside of the device, or check in the system settings (e.g., "About This Mac" or "System Information" on Windows).
  • Mobile phones and tablets: Dial *#06# to display the IMEI, or check Settings > About Phone. The IMEI is also printed on the original box.
  • Musical instruments: Guitars typically have a serial number on the headstock or inside the sound hole. Brass and woodwind instruments usually have it engraved near the bell or on the body.
  • Power tools: Check the nameplate or rating label, usually located on the body of the tool near the motor housing.
  • Cameras: Look on the bottom of the camera body. The serial number is also typically recorded in the EXIF data of photos taken with the camera.

How to use SerialCheck to verify

Before you hand over your cash, ask the seller for the item's serial number and search it on SerialCheck. Our registry is free to use and does not require an account to search. Simply enter the serial number on our homepage and you will instantly see whether the item has been reported as stolen.

If the item comes up clean, you can buy with much greater confidence. If it has been flagged, walk away and consider reporting the listing to police.

Red flags when buying second-hand

Beyond checking the serial number, watch out for these common warning signs:

  • Price too good to be true: If a $3,000 mountain bike is listed for $400, there is probably a reason.
  • No receipt or proof of purchase: Legitimate sellers usually have some form of documentation, even if it is just an email confirmation.
  • Serial number removed or obscured: If the serial number has been scratched off, filed down, or covered with a sticker, that is a major red flag.
  • Seller is vague or evasive: If they cannot answer basic questions about the item — when they bought it, where they bought it, why they are selling — be cautious.
  • Rushed sale: Pressure to buy quickly, meet in unusual locations, or pay in cash only can all indicate something is not right.
  • Multiple high-value items from one seller: If someone is selling five laptops and three bikes simultaneously, that warrants suspicion.

Tips for safe second-hand purchases

Whether you are buying on Gumtree, Facebook Marketplace, eBay, or through local community groups, follow these guidelines:

  • Always meet in a safe, public location. Many police stations across Australia now offer "safe exchange zones" specifically for this purpose.
  • Ask for the serial number before you meet and check it on SerialCheck in advance.
  • Request a receipt or proof of purchase. A screenshot of the original order confirmation or a photo of the receipt is usually sufficient.
  • Pay via bank transfer or PayPal where possible, so there is a record of the transaction. Avoid large cash payments.
  • Trust your instincts. If something feels off, it is better to walk away than risk buying stolen property.

Checking a serial number takes less than thirty seconds and could save you from losing your money, facing criminal charges, or inadvertently supporting property crime. Make it a habit — every time, no exceptions.

Search a serial number now on SerialCheck — it is free, fast, and could save you a world of trouble.