An unknown device appears on your Apple Account

An unfamiliar name in your Apple Account device list deserves a check, but a renamed computer or an old phone can look unfamiliar. First distinguish a device you own from a sign-in you did not authorize. Do this from Settings on a device you control or by typing Apple's account address yourself, never through a security-alert link.

Check and contain​

1. On iPhone or iPad, open Settings → your name and scroll to the devices. On a computer, sign in at account.apple.com and choose Devices. Open the entry for its model and other details; compare it with your current and retired devices.
2. If it is not yours, select Remove from Account. Apple says this remotely signs the device out and stops it displaying verification codes. If you still own the device and it remains signed in, it can reappear when it connects; sign out on that device or erase it before disposal.
3. Change your Apple Account password from a trusted device. Review email addresses, phone numbers and other security information at account.apple.com. Remove only recovery methods you do not recognize; keep a working method under your control.
4. Check purchases, messages and iCloud activity for changes you did not make. Contact your payment provider promptly about unauthorized charges; changing the password does not reverse a purchase.

If you cannot sign in​

Use Apple's account recovery at iforgot.apple.com. Its waiting period can take days, and support cannot shorten it. Someone offering a faster recovery in a direct message is not a substitute. Apple's compromise checklist and device-list instructions distinguish account control from device removal. If a phone is physically missing too, use our lost-phone checklist; removing an account entry alone does not locate or erase the phone.