Deliver OTPs by voice call when SMS fails or isn't trusted- an automated call reads the code aloud, with a repeat option, so customers can verify even when a text message doesn't land.
One account for Voice, SMS, WhatsApp & RCS OTP · 10,000+ Indian businesses
Trusted by 10,000+ businesses across India
Voice OTP replaces the text message with a phone call. Instead of a customer receiving an SMS with a numeric code, an automated call reaches their number and a text-to-speech system reads the code aloud- typically slowly, digit by digit, with an option to hear it again. The customer then enters that code into your app or website exactly as they would with an SMS OTP; only the delivery step changes.
Most businesses don't use Voice OTP as their only channel. It works best layered underneath SMS- triggered automatically when an SMS OTP attempt fails to deliver or times out- so the customer still gets a working verification path instead of getting stuck.
In poor-coverage areas or during carrier congestion, SMS OTPs can arrive late or not at all- a voice call over the same network often still connects.
International roaming can make SMS OTP slow, costly, or unreliable, and some users disable SMS entirely- voice calling reaches them through a different delivery path.
Some users prefer or need audio delivery over reading a text message- voice OTP reads the code aloud, at a deliberate pace, with a repeat option.
Most businesses trigger voice OTP automatically only after an SMS OTP attempt fails to deliver- one extra chance to reach the customer before the flow breaks.
An automated outbound call is placed to the customer's number, usually after an SMS OTP attempt has failed or timed out.
A text-to-speech system reads the numeric code slowly and clearly, digit by digit.
The customer can press a key- typically "press 1"- to hear the code again if they missed a digit.
The customer types the code into your app or website exactly as they would with an SMS OTP- the verification step doesn't change.
SMS OTP is faster and cheaper at scale for the vast majority of successful deliveries. Voice OTP is best reserved for the delivery failures and edge cases where SMS didn't land.
| Aspect | SMS OTP | Voice OTP |
|---|---|---|
| Typical delivery speed | Seconds, at scale | Seconds, but requires the call to be answered |
| Cost at scale | Lower per successful delivery | Higher- a live call costs more than a text |
| Best role | Primary channel for the vast majority of OTPs | Fallback for the delivery failures and edge cases SMS misses |
| User experience | Fast, silent, works with the screen locked | Requires answering a call and listening actively |
Typical delivery speed
Cost at scale
Best role
User experience
Voice OTP isn't meant to stand alone- it's one tier in a layered OTP-delivery strategy that most Get Click Media clients run: SMS OTP as the primary channel for speed and cost, WhatsApp or RCS OTP where the customer has opted in and the app is installed, and Voice OTP as the fallback that catches the delivery failures the other channels miss.
Read how Voice OTP fits alongside SMS and WhatsApp OTP, and alongside SMS and RCS OTP, in our detailed channel comparisons.
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Voice OTP is a one-time password delivered through an automated outbound phone call instead of- or as a fallback to- SMS. The system calls the customer's number and uses text-to-speech to read the numeric code aloud, which the customer then enters into your app or website as normal.
Get Click Media layers Voice OTP underneath your SMS, WhatsApp, and RCS OTP delivery- so verification codes reach customers even when a text message doesn't land.
