Two-factor authentication
2FA requires two independent proofs to log in: something you know (password) plus something you have (a phone receiving a code, an authenticator app or a hardware key).
What is Two-factor authentication?
2FA requires two independent proofs to log in: something you know (password) plus something you have (a phone receiving a code, an authenticator app or a hardware key).
SMS as a second factor
SMS 2FA sends a code to the phone number on the account. It is convenient but exposed to SIM swap and phishing, so services increasingly prefer authenticator apps or passkeys.
Using a rented number for 2FA
If an account's second factor is SMS, the number must still be yours at the next login. Rent the number rather than buying a one-time activation, or switch the account to an authenticator app after sign-up.