Surprised nobody has mentioned NIST SP 800-63B §5.1.3.3. SMS based authentication is explicitly insecure and not allowed. https://pages.nist.gov/800-63-3/sp80

Surprised nobody has mentioned NIST SP 800-63B §5.1.3.3. SMS based authentication is explicitly insecure and not allowed. https://pages.nist.gov/800-63-3/sp800-63b.html#pstnOOB https://pages.nist.gov/800-63-3/sp800-63b.html#pstnOOB