Safety and legal
Privacy, legality and good practice with temporary numbers.
Is using a temporary phone number legal?In most countries, yes: receiving an SMS on a number you rented is lawful. What changes it: the app's terms, fraud, impersonation, KYC services.
Keep your phone number off data broker listsYour number links your accounts across data brokers. How sign-ups leak it, why spam calls follow, and how a temporary number for minor accounts breaks the chain.
OTP and two-factor authentication explainedWhat a one-time password is, how SMS 2FA differs from authenticator apps and passkeys, where SMS codes are weak, and how to use temporary numbers with 2FA safely.