Every bicycle has a unique serial number – and for anyone buying or selling a second-hand bike in Australia, that number is one of the most important pieces of information you can find. It’s the difference between buying a legitimate used bike and unknowingly purchasing stolen property.
In this guide, we cover exactly where to find a bike’s serial number, which Australian registers and databases to check it against, what to do if a serial number is missing or tampered with, and how a professional Rideworthy inspection keeps you protected.
Where to Find a Bicycle’s Serial Number
The serial number (sometimes called the frame number) is stamped, engraved or printed on the frame at the time of manufacture. On the vast majority of bicycles, you’ll find it in one of these locations:
- Bottom bracket shell: the most common location – underneath the frame, in the centre where the pedals meet. Look directly below the chainring area.
- Chain stay: the tube running from the bottom bracket towards the rear dropout
- Head tube: on some older or European bikes, the serial number may be near the steering tube at the front
- Seat tube: occasionally stamped on the vertical tube below the saddle
As the NSW Government notes, most bicycles carry a unique serial number stamped on the underside of the frame. If the number is not immediately visible, a torch helps – particularly on dark anodised frames.
On e-bikes, you may find both a frame serial number and a separate battery or motor serial number. Both are worth recording.
Rideworthy Tip: Photograph the serial number before any purchase. Keep the image in your phone’s camera roll along with the seller’s details. If a dispute arises later, you’ll have timestamped evidence of the number at the time of sale.
Australian Registers to Check a Bike’s Serial Number
Australia has several registers where stolen bikes are reported and where you can cross-check a serial number before purchasing. Here are the key platforms to know:
Bike Index
Bike Index is a free, international non-profit bicycle registration and stolen bike database. Rideworthy is a partner organisation with Bike Index, and the platform already has over 568 bikes registered through the network. You can search Bike Index by serial number at bikeindex.org to check whether a bike has been reported stolen anywhere in Australia or internationally.
BikeVAULT (formerly National Bike Register)
BikeVAULT is an Australian registration service that has absorbed the old National Bike Register (NBR). The platform allows owners to register their bikes (free) and provides a searchable database. BikeVAULT also offers theft recovery assistance led by police-trained specialists.
Bikelinc
Bikelinc is powered by Crime Stoppers WA and is used in Western Australia, the ACT and Tasmania. It allows both registration and searching for lost or stolen bikes using serial numbers. Police can search the database to identify owners of recovered bikes.
PPSR (Personal Property Securities Register)
While primarily designed for motor vehicles, the PPSR – the government database that replaced the old REVS system in 2012 – can be searched using a vehicle serial number. The PPSR can reveal whether a bicycle or e-bike has any finance owing against it, or has been recorded as stolen or written off. A basic search costs a few dollars at ppsr.gov.au and is worth conducting for higher-value bikes.
How to Conduct a Serial Number Check: Step by Step
- Ask the seller to show you the bike’s serial number in person before agreeing to anything
- Photograph the number clearly with your smartphone
- Search Bike Index using the serial number – it’s free and takes under a minute
- Search BikeVAULT for additional Australian records
- If in WA, ACT or Tasmania, also check Bikelinc (bikelinc.com.au)
- For higher-value bikes, run a PPSR search at ppsr.gov.au
- If any result shows the bike as stolen or encumbered, do not proceed with the purchase and consider notifying police
What If There’s No Serial Number?
A missing or tampered serial number is a serious red flag when purchasing a used bicycle. While some older bikes – particularly those manufactured before the late 1980s – may not carry serial numbers as a standard, a missing or scratched-out number on any modern bicycle should prompt extreme caution.
Thieves commonly remove or grind off serial numbers to make stolen bikes harder to trace. If you’re inspecting a bike and the number appears to have been deliberately removed, consider walking away from the purchase entirely.
The NSW Government recommends that if your bicycle does not have a serial number, you can engrave your own identification number and record the details separately.
Rideworthy Tip: A Rideworthy certified inspection includes verification of frame details and documentation of the serial number as part of the inspection report. This gives buyers an independent record of the bike’s identity at the time of purchase.
Registering Your Bike After Purchase
Once you’ve purchased a bike, register it immediately on Bike Index and/or BikeVAULT. Registration is free and takes less than five minutes. In the unfortunate event of theft, a registered bike with a documented serial number gives police the best chance of identifying and returning it to you.
Victoria Police notes that all bike owners should take note of and record their serial numbers in a safe location. Don’t wait until after a theft to discover you never recorded it.
Verifying the serial number is just one part of a safe purchase – make sure you also know the other things to check before buying a secondhand bicycle. Buying a used bike in Sydney, Melbourne, Brisbane, Perth, Adelaide or Canberra? A Rideworthy bicycle inspection report documents the bike’s serial number, frame condition and component state – giving you independent, certified proof of what you purchased. Book at Rideworthy.