Deliver OTPs as a voice call
Some codes don't arrive by SMS — a failed delivery, a landline, a number with patchy text. Voice OTP reads the code aloud on a call, so verification still completes when SMS can't reach. Set it as a fallback and it costs nothing until it's used.
When a code needs to be heard
Voice OTP places a call and reads the one-time code aloud, digit by digit, in the language you choose. Most often it's a fallback: if an SMS code isn't delivered within a window, the same code goes out as a voice call, with the verification unchanged so your verify step doesn't branch. It can also be the primary channel where the audience suits it.
It reaches numbers SMS doesn't. A landline can't receive a text but takes a call; a feature phone or an older customer may find a spoken code easier than a written one; a number with unreliable SMS delivery still rings. For accessibility and reach, voice fills the gaps a text leaves.
Like an SMS OTP, a voice OTP is service traffic — a response to the user's own action — so it reaches the customer without NDNC scrubbing, and the same expiry and attempt caps apply. The code is generated, delivered, and verified on our side; you only ever call verify, exactly as you would for SMS.
As a fallback it costs nothing until it's needed: an SMS that lands never triggers a call, so you pay for voice only on the verifications SMS couldn't complete. Where it does fire, it turns a failed verification — and a locked-out customer — into a completed one.
What’s included
Read aloud
The code is read digit by digit in the language you choose.
Triggers on SMS failure
Fires only when an SMS code isn't delivered in time.
Landlines and feature phones
Rings numbers that can't receive an SMS at all.
Unchanged verification
The verification_id and verify call don't change.
No NDNC scrubbing
A service OTP call reaches the customer as a response.
Pay only when used
A delivered SMS never triggers a call, so voice is used sparingly.
Frequently asked
When should I use voice OTP?
As a fallback for SMS, and as a primary channel for audiences that suit it — landlines, feature phones, older customers, or markets with unreliable SMS delivery. As a fallback it lifts your overall verification completion rate without you changing the verify call.
What languages can the code be read in?
Hindi, English, and the major regional languages. The digits and the brief wrapper around them are spoken in the language you set, so a customer hears the code in a language they understand rather than a default they may not.
Does voice OTP change my integration?
No. It sits on the same verification: the send can be configured to fall back to voice after a window, and your verify call is identical regardless of whether SMS or voice delivered the code. The expiry and attempt caps carry over unchanged.
How is voice OTP priced?
As a short voice call, with GST shown separately, and charged only when a call is actually placed. Because a delivered SMS never triggers one, voice OTP adds reach at the margin rather than a cost on every verification. See the pricing page.