Everything held on your account is removed from Telegram: all messages, groups and contacts associated with it. The deletion is irreversible. There are two consequences people usually do not expect.
What survives, and why
- Groups and channels you created keep running. They are left without a creator, but the members remain and the administrators keep the rights they already had. A community does not collapse because its founder left.
- Other people keep their copy of what you sent them. Deleting your account removes your side. It does not reach into somebody else's chat history and remove messages they received.
If the goal is for messages to disappear
Account deletion is the wrong tool. Use the self-destruct timer, which removes a message from both devices when the time expires, or delete specific messages for both sides, which leaves no trace at all in the conversation. Deleting the account is about ending the account, not about retracting what you said.
Signing up again later
Registering the same number afterwards creates a new, empty account. No messages, no contacts, no groups, and no username if somebody claimed it in the meantime. Nothing is recovered, because nothing was retained.
Before deleting, export your data from Settings, Advanced, Export Telegram Data, and hand ownership of any channel or large group to somebody you trust. Neither is possible afterwards.
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