Username is Public: Your username itself is public. Anyone can search for it and see your profile picture, chosen display name, and about info. The privacy settings for your phone number apply after they find your profile.
Phone Number is Always Required for Account Creation: While usernames facilitate privacy, you still need a phone number (personal, virtual, or Fragment's +888) to create and register your Telegram account initially. The username is an additional layer of privacy once the account is established.
Mutual Contacts Who Already Have Your Number: If someone already has your phone number saved in their phone's address book and you have them in your contacts, they might still see your number if your "Who can see my phone number?" setting is "My Contacts" or "Everybody." However, if it's set to "Nobody," they won't see it on your Telegram profile, even if they have your number elsewhere.
"People Nearby" Feature: Be aware that the "People Nearby" feature (if enabled) can expose your proximity to others, but it does not directly expose your phone number if your privacy settings are configured correctly. It's generally recommended to turn this off if you prioritize anonymity.
Best Practices for Maximizing Phone Number Privacy with a Username:
to "Nobody." This is the most crucial telegram number database step.
Set "Who can find me by my number?" to "Nobody" or "My Contacts" (depending on your comfort level). "Nobody" is the most private.
Always use a username for communication, especially in public groups or with people you don't know personally.
Avoid sharing your phone number manually within chats unless absolutely necessary.
Enable Two-Step Verification (2FA) to secure your account even if your phone number somehow gets compromised.
Consider using an anonymous number (like Fragment's +888) or a virtual number for registration if you want to completely decouple your Telegram account from your personal phone identity.