An AirTag for bike security is the cheapest upgrade most riders will ever make, and the one most often fitted badly, because a single tag stuck under a saddle usually gets found and binned. Two tags, fitted with some thought and set up in advance, cost less than a decent lock and give a recovery team something to work with.
This guide covers how many to buy, the fitting principles our team works to, the Find My settings that matter once a bike is gone, and what to do when a tag starts moving. For how tags compare with proper GPS units, read our guide to the best bike trackers in the UK.
Fit two AirTags, not one
Apple's own safety features work against you here, because nearby iPhones are alerted when an unknown AirTag is travelling with them and the tag beeps by itself. The second generation AirTag has Apple's loudest tag speaker yet, which is handy down the back of a sofa and unhelpful on a stolen bike. Assume the first tag will be found.
That is the argument for fitting two. The first tag is a decoy, because thieves who find one usually stop looking, and the second carries on reporting. Our recovery team watched that happen in east London, where one tag was ripped off quickly, the second kept pinging in an area full of iPhones, and the bike turned up locked to railings nearby.
- One AirTag is £29 and a four pack is £99, so two tags cost around £58, or about £50 a bike if you split a pack between two bikes.
- Set both up before the bike next leaves the house, rather than after something happens.
- Name the two tags differently in Find My, so you know at a glance which one is still reporting.
Where to fit them, and where not
Most people searching for an AirTag for bike use want one answer, which is where it goes. We do not publish hiding places, because thieves read buying guides too and a list of spots is a checklist for stripping trackers off a bike in a car park. What we will publish are the principles our fitters work to: a tag should be covert, dry, not fully wrapped in metal, and not the first place anyone looks.
The physics is simpler than it sounds, because unlike GPS a Bluetooth tag needs no view of the sky. Picture a sphere of signal around the device: things in the way shrink the sphere, they do not make it vanish. A tag therefore tolerates places a GPS unit will not, so long as it is not sealed inside metal.
How you fix a tag matters as much as where. A decent mount runs from £5 to £25 and is worth buying, but keep clear of the bottle cage bosses, because that is one of the first places a thief looks. Keep both tags away from water and road spray, and out of a metal housing that would smother the signal. Since you are fitting two, they should fail differently, with the decoy quick to reach and the second costing a thief tools and time.
A tracker is the recovery layer rather than the prevention layer, so pair whatever you fit with a properly rated lock.
Set up Find My before you need it
Turn on Lost Mode straight away
Marking an item as lost lets you show your contact details to whoever finds it, and Apple's instructions are to tap Lost Mode or Show Contact Info. Do it the moment you know the bike has gone, rather than after an hour of walking the street. Find My will also share a lost item's location with somebody else, useful when the police or a recovery team are helping.
Know what Precision Finding will do
Precision Finding is the arrow that walks you in over the last few metres, and it needs an iPhone with Ultra Wideband, with Apple naming iPhone 15 and later for the newer Find Nearby version. It only helps once you are already on top of the bike, which in a live theft is exactly the part you should not be doing alone.
Check the battery twice a year
An AirTag runs on a user replaceable CR2032 coin cell that Apple says lasts more than a year, so play a sound from the app every few months. A tag with a flat battery is a sticker.
What to do when a tag starts moving
Do not go and collect the bike yourself, because the people who have it are not expecting a conversation and a phone showing a blue dot proves very little on a doorstep.
- Report the theft to the police and get a crime reference number.
- Screenshot the location history with times, so the trail is evidence rather than memory.
- Share the item location with whoever is helping you recover the bike.
- Tell your insurer today, and if your cover includes recovery, tell them before you think about a claim.
The first hours matter more than the rest of the week, and our guide to what to do if your bike is stolen sets out the order. Be realistic about what a tag gives you, because the Find My network puts you in a street or a building rather than on the bike, and closing the last few metres is what proximity detection is for.
AirTag bike FAQ
Can a thief tell there is an AirTag on my bike?
Yes, because Apple alerts nearby iPhones when an unknown AirTag is travelling with them and the tag beeps on its own. No hiding place changes that, which is the main reason we suggest fitting two, so the tag a thief finds acts as a decoy for the one they miss.
Do AirTags need a subscription?
No, because Bluetooth crowd network tags have no SIM and no monthly fee, borrowing the phones that walk past them instead. Cellular GPS trackers need mobile data, so they carry a fee of some kind, which is why any tracker is best compared over three years rather than on its sticker price.
Will an AirTag work in a lock-up or a block of flats?
It depends entirely on who walks past, so on a busy high street updates arrive often and accuracy is good. In a lock-up behind a block of flats a tag can go a long time without an update, and may then put you on a row of houses rather than a door.
Is an AirTag enough on its own?
No, because it is a cheap extra layer rather than a recovery plan. Reporting where something is differs from getting it back, which needs a device the theft did not remove, proximity detection for the last few metres, and somebody able to attend.
The bottom line
Two tags fitted to those four principles, named in Find My and backed by Lost Mode, turn an AirTag for bike security from a gesture into something a recovery team can use, although it remains the cheapest layer you can add and the weakest. BackPedal fits a covert tracker to every bike we cover and sends a team after it.