How SaaS Teams Should Own OTP Templates for Secure Password Resets

For B2B SaaS password-reset flows, security experts recommend keeping OTP template logic and challenge state within the application itself rather than delegating it to third-party delivery vendors. Both SMS and email are viable channels, but the choice should be treated as a delivery adapter decision, not a security one — the application must control code lifetime, content, and rate limits. A single, atomically consumed challenge record is advised to prevent race conditions where multiple delivery channels could each hold a valid code simultaneously. Template ownership is framed as a core security boundary, since the message content itself can be a vector for user confusion or attacker exploitation. Retention policies for challenge logs should be made configurable to accommodate differing US and EU legal requirements, and reset flows must require a previously verified destination address.