Even if you delete a contact, your existing chat history with them on Telegram usually remains visible in your chat list until you explicitly delete the chat itself.
Their Privacy Settings: You can only add someone as a contact if their Telegram privacy settings allow them to be found by phone number. If they have set "Who can find me by my number?" to "Nobody," you might need their username to add them, even if you have their number.
Username as Alternative: If you struggle to re-add them via phone number (e.g., due to their privacy settings or issues with their number), you can always ask them for their Telegram username (@username) and search for them directly that way.
They Don't Get Notified (Usually): Telegram generally does not notify someone when you delete them as a contact or re-add them. Notifications typically occur when a contact joins Telegram.
In essence, "recovering" a deleted contact using their telegram number database phone number involves treating them as a new contact and re-adding them to your address book and/or Telegram manually.
When you "delete" a contact in Telegram, you're primarily removing them from your Telegram's contact list and, optionally, from your phone's address book. Telegram doesn't have a "trash" or "recycle bin" for contacts. To "recover" them using their phone number means re-adding them.
Here's how to do it:
1. Understand What "Deleting a Contact" Means on Telegram:
Removes from your Telegram list: When you delete a contact within the Telegram app (by going to their profile, tapping "Edit" or "More," and then "Delete Contact"), they are removed from your list of contacts within the Telegram app.