Flash call

Verification by a brief incoming call where the last digits of the calling number are the code, so the call never needs answering.

A flash call verifies a number without an SMS: the service rings the number and hangs up, and the app reads the last few digits of the caller ID as the verification code. It is cheaper for platforms than SMS in many markets and faster when SMS routes are congested.

MarioSMS supports flash-call and voice activations for services that offer them, alongside standard SMS.