Where to find a bike's serial number
Check these spots, in order — flip the bike upside down first:
- Under the bottom bracket (where the pedal cranks meet the frame) — the most common location
- Head tube, rear dropout, or seat tube
- On the original receipt or owner's registration
A seller who won't send you a photo of the bottom bracket before you drive across town has told you everything you need to know.
What we check
Your search runs against theft registries including stolen bicycle databases, the largest bicycle registration database in the world, plus our own submitted-theft records. If the serial matches a theft report, you'll see when and where it was reported.
The price test
Before you even check the serial: look up the model's retail price. A $1,400 bike listed at $250 with a "moving, must sell today" story is the single most reliable stolen-bike pattern there is. Thieves price for speed, not value.
If your own bike was stolen
Register the serial with us and with stolen bicycle databases immediately — recovery almost always happens because a buyer or a shop ran a check. Report a stolen bike →
Frequently asked questions
How can I check if a used bicycle was stolen?
Find the serial number stamped into the frame — usually underneath the bottom bracket where the pedal cranks meet — and enter it at SafeOrStolen before you buy. SafeOrStolen searches that serial against stolen property reports from all 50 states, insurance claim records, and community theft registries. Ask the seller to photograph the frame serial before you travel; a refusal is the most common warning sign on a stolen bike.
Is there a stolen bike database?
There is no single national stolen bicycle database that covers every theft — reports are split between individual police departments, insurers, and community theft registries, and many stolen bikes were never registered by their owner in the first place. SafeOrStolen searches across those theft records from one place using the frame serial. A no-match result means nothing was found in the sources checked, not proof the bike was never stolen.
How do I check a bike serial number?
Turn the bike upside down, read the serial stamped into the frame, and enter it at SafeOrStolen — the check takes a few seconds and returns a match or no-match result plus a dated verification record. Compare the number you read against any number the seller sent you in advance. If the serial has been filed, ground off, or painted over, do not buy the bike.
Where is the serial number on a bicycle?
On most bikes the serial is stamped underneath the bottom bracket, the shell the pedal cranks pass through, so you need to flip the bike over to read it. Other common locations are the head tube at the front, the rear dropout near the back wheel axle, and the underside of the seat tube. The same number should appear on the original receipt or registration if the seller still has it.