Why should I add a phone number to my Steam account?

Adding a phone to your account gives you more options to recover your account in case you forget your password, or if your account is stolen. You can use SMS messaging to reset your password, or transfer your Steam Guard Mobile Authenticator from one phone to another.

K obnově Steam stačí obyčejná SMS - ale to si musí uživatel nastavit v profilu telefonní číslo (otázka 20 vteřin). Ale to by nebylo ono, že.