Lost Your Phone? What to Do About Your Telegram Account

First: whoever has the number has the account

Telegram's FAQ is blunt about it: the phone number is the only way Telegram identifies you, it collects nothing else about you, and "whoever has the number, has the account." So Telegram can only help if you still have one of two things: the phone number, or Telegram logged in on another device. Work out which you have, then follow that list in order.

If Telegram is logged in on another device

A computer, tablet or second phone that is still logged in is your best tool. Do these three things from it, in this order:

1. Turn on Two-Step Verification in Privacy and Security, if it is not on already. From then on, the number alone is not enough to log in, so a thief with your SIM cannot get back in.
2. End the lost phone's session. Open Devices (in Telegram Desktop: Privacy and Security, Active sessions), tap the lost phone and choose Terminate Session. If you are not sure which one it is, use Terminate All Other Sessions, which "logs out all devices except for this one."
3. Contact your phone provider to block the old SIM and issue a new one with your number.

Once the session is ended and a password is set, whoever has the phone cannot log back in, because they do not know the password.

If you have no other device

1. Call your phone provider first. Ask them to block the old SIM and give you a new one, or an eSIM, with the same number.
2. Log in on your new phone with that number. If Two-Step Verification was on, enter the password after the code.
3. End the old phone's session from Devices on the new phone.

Until the SIM is blocked, the old phone can still receive your codes. That is why the provider comes first when you have nothing else.

Worried about what is on the phone

The FAQ points out that ordinary thieves usually throw the SIM away straight away and wipe the phone to sell it, so there is not much risk to your data in a typical theft. If you have reason to worry and cannot log the phone out, wipe it remotely: Find My on an iPhone, or Google's Find Hub (formerly Find My Device) on Android. That only works if it was switched on beforehand.

If you are getting a new number instead

If you decide not to keep the old number, change the number on your Telegram account from a logged-in device: tap your number in Settings and change it. The FAQ notes that this keeps everything, including your chats, contacts and media. Do it before the old number is given to someone else. Changing your number without losing chats walks through it.

If you have lost the number, the device and the password all at once, see account recovery. Next step: one account on two phones, and eSIM setups.