You can write to anyone you can identify, and there are several ways to identify them. A phone number is only one of them, and increasingly the least used.
The ways to start a conversation
- A contact. Anyone in your contacts who also uses Telegram appears at the top of your Contacts.
- A username. Search for @name and message the account directly, without ever exchanging numbers.
- A t.me link. Opening t.me/name in any browser leads straight to the chat.
- A shared group. Tap someone's name in a group you are both in to open a private chat, subject to their privacy settings.
- A QR code. Each account has one under Settings. Scanning it opens the chat, which is the quickest way to swap details in person.
- A phone number. Add it as a contact in the usual way.
When someone cannot be reached
Privacy settings are the usual explanation. A person can restrict who may add them to groups, who can see their number, and who may message them at all. If a chat cannot be opened, it is almost always a deliberate setting rather than a fault, and there is nothing to work around.
New accounts are limited on purpose
A brand new account that starts messaging a long list of strangers will hit rate limits quickly. This is anti-spam behaviour and it eases as the account is used normally. If you are setting up an account for a business, build the audience through a public username and an invite link rather than by messaging people first.
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