Losing a phone sets off a rush of panic, and that is when people make mistakes like erasing a phone they could have found. Work through these steps in order.
1. Ring it
Call it from someone else's phone, or use Play Sound in Find My or Find Hub. Play Sound works even if the phone is on silent.
2. Check the map
From a friend's phone or any computer, sign in at icloud.com/find (iPhone) or android.com/find (Android). Note the time next to the location, because it may be the last place the phone was seen rather than where it is now.
3. Lock it before you do anything else
Use Mark As Lost (iPhone) or Secure device (Android). The phone locks, and you can put a contact number on the lock screen for whoever finds it. Hold off on erasing it until you have tried everything else.
4. Retrace and call around
Ring the last venue, taxi firm, or train operator's lost property office. Most phones that go missing are simply left behind.
5. If it has been stolen
Do not try to recover it yourself, even if you can see where it is. Report it to the police on 101 or online and get a crime reference number, which your insurer will need. Then ask your network to block the SIM and the handset.
6. Secure your accounts
If the phone had no passcode, change the passwords for your email and banking straight away, and tell your bank. Keep an eye out for unexpected "your SIM has changed" messages.
