Flash call OTP
Missed-call verification that proves the handset — not SMS Verify and not voice alerts.
When CLI is Blocked, Fallback Must Be Honest
Learn how to handle blocked caller line identification in flash-call verification honestly. Avoid false Verify OK states and route to SMS OTP fallback correctly.
Flash-Call Proof Before Production Login
Learn how to verify CLI presentation for flash-calls before moving to production login. Understand the JIT allocation model, prepaid ledger rules, and webhook validation.
Flash-Call OTP Is Not SMS Verify
Understand the core mechanics of flash-call OTP as a missed-call proof of the handset. Learn why it is not an SMS OTP product and how it differs from voice alerts on the IOSOR platform.