If you want to keep using an account you created with a one-time phone number, add login and recovery options that don't depend on that number as soon as verification is done. The number won't be yours the next time the platform asks for a code, so don't put these steps off.
Why the first day matters
Platforms don't use your number only at sign-up. They also send codes to it when you log in from a new phone, reset your password, return to an account after a long break or trigger a security check. When that happens, the code goes to the number you signed up with. Without access to it, you can only get back in with the email, password or backup codes you added beforehand.
Four steps for any account
- Add and confirm an email address. Most recovery happens by email.
- Turn on two-factor authentication. Where possible, choose an authenticator app instead of SMS, so login codes go to the app rather than the number.
- Save backup codes. If the platform offers backup or recovery codes, store them offline somewhere safe.
- Stay signed in on at least one device. Some platforms send new login codes to your active sessions.
Go to Settings > Account > Two-step verification, set a 6-digit PIN and add your email address. As WhatsApp explains in About registration and two-step verification, re-registering your number then requires the PIN too. Someone who later gets the same number can't easily register your account on their phone without it.
If you later want to move the account to your own number, use Settings > Account > Change number. The verification code for this step goes to the new number.
Telegram
Go to Settings > Privacy and Security > Two-Step Verification and set a password and recovery email. Because Telegram can send login codes to devices where you're signed in, keeping the account open on your computer makes logging in on new devices easier. See how the feature works in Telegram's FAQ.
Google (Gmail)
In your Google Account's Security section, add a recovery email and turn on 2-Step Verification. For the second step, choose an option that doesn't rely on the number, such as Google Authenticator or Google prompts on your phone. Download Google's backup codes and keep them safe; they let you sign in if you lose your phone or number.
Instagram and Facebook
In Accounts Center, open Password and security, turn on two-factor authentication and choose an authentication app as the method. Add an email address to the account and confirm it. Save the recovery codes you're given when you enable two-factor authentication.
Which accounts should use your own number?
Use your own number for banking, government services, payment apps and your main work email: accounts you need long term and that are linked to your identity. On these, the number confirms transactions and identity as well as logins.
If you'll need the same number again over a few days, see how one-time and rental numbers compare. To understand two-factor authentication itself, read our guide to OTP and 2FA.