My phone says an unknown tracker is moving with me — what should I do?

Small Bluetooth trackers are genuinely useful things attached to keys, bags and luggage, and they work by quietly borrowing the location of every passing phone. That same mechanism makes them usable for following a person, which is why Apple and Google agreed a shared specification so that a phone of either kind will notice a tracker that is not yours moving with you, whichever platform it was paired with. The alert is a good feature working correctly. It is also alarming to receive, arrives with almost no explanation, and is most often triggered by something entirely ordinary. Working through it calmly, in order, is the aim here — and knowing what to do if the ordinary explanations run out.

Safety

Step by step

1. Read the alert properly before doing anything else.Tapping it opens a map showing where and when the tracker was detected near you. That history is the most useful thing you have: a tracker seen with you across several separate journeys is a different matter from one seen once on a single train. Screenshot the map and the times now, because the record is more useful than your memory later.
2. Rule out the ordinary explanations, because most alerts are one of them.A partner's or a friend's keys in a shared bag. A borrowed coat. A hire car or a courtesy car with a tracker left in it. A taxi or a lift where someone else's luggage travelled with you. An item you bought second-hand with a tracker still inside. A tracker in a delivery. In a household where several people carry trackers, alerts on a shared car journey are routine.
3. Make it play a sound, which is the fastest way to find it.The alert offers to make the tracker beep. Search the obvious places while it sounds: coat pockets and linings, bag seams and base panels, the inside of a case, under and behind car seats, in the boot lining, in the glovebox, under the spare wheel cover, in a pushchair or a rucksack. Some trackers have had their speakers deliberately disabled, so silence does not prove there is nothing there.
4. Use the alert's identify option before touching anything.Both platforms can read the tracker's identifier by holding the phone near it, and can show whether the owner has marked it as lost, which sometimes displays a contact message and explains the whole thing. This also records the serial number, which is what the police will need.
5. Do not destroy it, and do not remove the battery in a hurry.The instinct is to break it or throw it away. If there is any possibility of a police report, that is the evidence and the serial number going in the bin. Photograph it in place, then decide. Disabling it stops the tracking; destroying it removes the only route to identifying who was doing it.
6. Think about where you are before you go home.If you believe someone may be following you, going home tells them where you live. Go somewhere public, or to a police station. This is the single most important line in this guide and it costs nothing to follow while you work out whether the alert was innocent.
7. Report it, with the evidence you have gathered.In an emergency call 999. Otherwise report to the police on 101 or through your force's online reporting, with the screenshots, the times, the locations and the tracker's serial number. Only the police can compel the manufacturer to identify the owner. Using a tracker to follow someone without their knowledge is capable of amounting to a criminal offence, and it is the police who assess that.
8. Get specialist advice if you have any suspicion about a specific person.If this involves a current or former partner, or anyone who has previously threatened or harassed you, contact a domestic abuse or stalking support service before making changes. They deal with this constantly, they can help with evidence and safety planning, and a change made in the wrong order can alert the person you are worried about. The catalogue's guide on untangling accounts after a relationship ends covers the wider picture.
9. Check whether anything else is following you.A physical tracker is one method among several. Location sharing left switched on in a phone's own settings, a shared family account, a linked account on a car, a shared cloud account, or an app installed on your phone can all do the same job. The catalogue's guides on signs someone has access to your phone and on app permissions are the ones to read next.
10. Know the limits of the alerting.Detection is not instant and not guaranteed. It relies on the tracker broadcasting, on your phone having Bluetooth on, and on the tracker being genuinely separated from its owner — a tracker whose owner is also travelling with you will not trigger anything. Some cheap trackers do not implement the standard at all. An absence of alerts is reassuring, not proof.

Common mistakes

• Ignoring the alert because it is probably nothing — It usually is nothing. The cost of checking is ten minutes; the cost of ignoring the one that matters is much higher. Rule it out rather than assuming.
• Destroying the tracker immediately — Understandable and it throws away the serial number, which is the only route to identifying who placed it. Photograph it, keep it, and let the police read it.
• Going straight home while worried you are being followed — If someone is tracking you and does not know where you live, that is the moment they find out. Go somewhere public first.
• Confronting the person you suspect — It removes any element of surprise from a police investigation and can escalate a dangerous situation. Report it and take advice instead.
• Assuming no alert means nothing is there — Detection depends on Bluetooth being on, on the tracker implementing the standard, and on it being genuinely separated from its owner. It is a good safety net and not a guarantee.

If it doesn't work

Questions people ask