E-Bike and E-Scooter Serial Numbers: Where to Find Them and How to Check a Used One

A regular bike has one serial number worth knowing. An e-bike usually has several: one on the frame, one on the motor, one on the battery, and often another on the display or controller. E-scooters are simpler, but they still keep their number in more than one place. Knowing where each one lives makes your bike or scooter far easier to identify if it's stolen, and it gives you a solid way to check a second-hand one before you hand over the money.

Why an e-bike has more than one serial number

Most e-bikes are built by one company and powered by another. The frame comes from the bike brand, while the motor, battery and display often come from a system maker such as Bosch, Shimano or Bafang. Each of those parts is manufactured and tracked separately, so each carries its own serial number.

That matters for two reasons. First, the battery is removable and valuable on its own, so thieves sometimes take just the battery and leave the bike. A battery with a recorded serial number is much easier to identify later. Second, when you're buying, the numbers on the different parts should tell a consistent story. If they don't, you want to know why.

Where to find the serial numbers on an e-bike

Frame

On most bikes the frame number is stamped into the metal underneath the bottom bracket, where the cranks pass through the frame. On many e-bikes the motor sits in that spot, so the number moves elsewhere: common places are the underside of the down tube, the back of the seat tube, the head tube or near the rear dropout. Some brands also add a QR code or barcode sticker beside the stamped number. If you can't find it, check the owner's manual or ask the brand. Turn the bike upside down, wipe off the grime and use your phone's torch.

Motor (drive unit)

Mid-drive motors carry a label or engraving on the housing, usually on the underside or the side facing away from the chain. Bafang motors have an identification badge on the casing that includes the model and a production serial. On Bosch systems you can also see the drive unit details on the display under Settings > My eBike > Components, or in the Bosch eBike Flow app under the bike's component settings. Shimano's E-TUBE PROJECT Cyclist app connects to Shimano e-bike components over Bluetooth and identifies the connected units, but the drive unit's own label is the place to copy the full number from.

Battery

The battery serial is on the type label stuck to the battery itself, which you usually only see once the battery is out of the frame or rack. For Bosch batteries, the number is also shown in the Flow or eBike Connect app, on the display under Settings, on the original invoice, and on the diagnostic report a dealer prints during a service. Remove the battery and photograph the label today, because it's awkward to find once the bike has gone.

Display and controller

Displays and remotes often have a small sticker on the back or underside. Hub-motor e-bikes and conversion kits frequently have a separate controller box with its own label. These parts are cheaper and easier to swap, so treat them as supporting evidence rather than the main identifier.

Where to find the serial number on an e-scooter

Segway-Ninebot scooters have the serial number on a sticker on the underside of the deck, and it is also shown in the Segway-Ninebot app under the scooter's device information. Xiaomi scooters usually carry it on the underside or side edge of the deck. Some newer models put a sticker near the charging port. It is also listed in the Xiaomi Home app: open the scooter's device card, tap the three-dot menu and choose Basic info. Don't be caught out by the QR code on the tyre or the sticker on the stem: those identify components, not the scooter.

For other brands, check under the deck, around the stem folding joint and inside the battery compartment, then look at the box and the user manual.

Checking a second-hand e-bike or e-scooter before you buy

E-bikes and e-scooters are expensive, easy to move and in steady demand, which makes them attractive to thieves and common on Facebook Marketplace and Gumtree. Before you meet a seller, and again when you inspect the bike:

1. Get the serial numbers first. Ask for the frame number at least, and ideally the motor and battery numbers too. Run each one through the SerialCheck search.
2. Check they match in person. Compare the frame number on the bike with what the seller sent you, and compare the motor and battery labels with what the app or display shows. On scooters, compare the deck sticker with the app. Controllers can be replaced, and the number an app shows comes from that electronics, so a mismatch deserves an explanation and a repair invoice.
3. Walk away from damaged numbers. A frame number that has been ground off, filed, painted over or restamped, or a battery label that has been peeled or scratched away, is a serious warning sign.
4. Ask for the receipt. A tax invoice from a bike shop normally lists the model and often the frame number. Bosch bikes may also have an eBike pass in the app that the owner can show you. No paperwork is not proof of theft, but it shifts more weight onto the other checks.
5. Take the battery seriously. Look for cracks, swelling, dents, water damage, taped-up casing or non-original chargers. NSW Fair Trading's advice for second-hand buyers is to check for an electrical safety approval mark, have a professional check the bike hasn't been modified, and never use a second-hand battery, because it could be damaged, modified or faulty. Be especially wary of anything advertised as "unlocked", "derestricted" or fitted with an upgraded battery.
6. Trust the usual warning signs. A price well under market, no charger or keys, a seller who won't meet at their home or let you test ride, or pressure to pay before inspecting are all reasons to pass. Our guide to buying safely on Marketplace and Gumtree covers the rest.

The NSW safety rules

Lithium-ion battery fires involving e-bikes and e-scooters have prompted regulation, and NSW has gone furthest so far. From 1 February 2025, only e-bikes, e-scooters and their batteries and chargers that comply with prescribed safety standards can be sold or supplied in NSW. From 1 February 2026, those products must also be tested by an accredited lab, certified and marked with a safety approval mark before sale. NSW Fair Trading says the requirements apply to second-hand sales too; whether a one-off private sale is caught is less clear, so treat a missing safety mark as a reason for caution either way. Other states have their own advice, so check with your state's fair trading or electrical safety regulator.

Whatever state you're in, the practical advice is the same: charge on a hard, non-flammable surface away from exits, in a room with a working smoke alarm, and don't leave a battery charging while you sleep or are out.

Buying stolen goods can cost you the bike and the money you paid, even if you had no idea. We explain why in why you should always check the serial number before buying second-hand.

If your e-bike or e-scooter is stolen

Report it to police and give them every serial number you have: frame, motor, battery and display, plus the make, model, colour and any stickers, accessories or damage that make it recognisable. If only the battery was taken, report that too, with its serial. Tell your insurer, and let the shop you bought it from know, since stolen bikes sometimes turn up for servicing. Then mark it stolen on SerialCheck so anyone who checks those numbers is warned. Our guide on what to do if your property is stolen walks through police reports and insurance claims step by step, and our tips to protect your bike from theft will help you avoid needing it.

Record it today

Five minutes with a torch and your phone camera is all it takes. Photograph the frame number, the motor label and the battery label, then register your e-bike or e-scooter on SerialCheck so there's a timestamped record of ownership if you ever need it. For everything else in the house, see our guide to where to find serial numbers on common items.