You can change your username on Telegram as many times as you want. People can find you by your username and contact you without knowing your phone number. Furthermore, someone can open a chat with you by using a link like this:
https://t.me/your_user_name
A username can only be used by one person. In addition, it must be at least 5 characters and contain only a-z, 0-9, and underscores.
The steps below show you how to update your username on Telegram.
1. Tap the hamburger icon in the top left corner to open the drawer menu then select “Settings”:
2. Tap on your current username. See the screenshot below to determine exactly the location:
3. Type your desired username into the text field. If someone has taken this username before, you must choose another username. Once the entered username is available, you can hit the button with the checkmark icon to save you change.
It’s important to note that a username is far different from a display name. Many people can user a display name but this isn’t allowed with a username. If you want to change your display name on Telegram, check this article.