# What is voice OTP?

> Voice OTP delivers a one-time passcode as an automated phone call that reads the code aloud, rather than as a text message. It is used as a fallback when SMS is undelivered or unsupported, for landlines and feature phones, and for accessibility — ensuring a user can still verify when a text cannot reach them. It is a core part of a resilient, multi-channel verification flow.

- Canonical URL: https://www.broadnet.me/answers/voice-otp-explained
- Language: en
- Last reviewed: 2026-09-24
- Publisher: BroadNet (https://www.broadnet.me)

## How it works

The platform places an automated call to the user's number and a text-to-speech voice reads the code, usually twice, with the option to repeat. Because it rides the voice network rather than SMS routes, it reaches numbers and situations SMS cannot. See /answers/programmable-voice.

## When to use it

Voice OTP shines as a fallback: when an SMS code is not delivered within a few seconds, when the number is a landline, or when the user requests it. It also serves accessibility needs for users who cannot read a screen easily. See /answers/best-channel-for-otp.

## Part of a verification waterfall

The strongest flows cascade channels — for example silent network authentication or SMS first, then voice — so a single failed channel never blocks a login. See /answers/silent-network-authentication and /answers/sms-fallback-strategy.

## Security and rate limiting

Like SMS OTP, voice OTP should be rate-limited per number to resist abuse and pumping, expire quickly, and be single-use. See /answers/sms-otp-best-practices.

## Related

- [All answers](https://www.broadnet.me/answers)
- [Glossary](https://www.broadnet.me/answers)
- [What is OTP?](https://www.broadnet.me/answers/what-is-otp)
- [What is the best channel for OTP delivery?](https://www.broadnet.me/answers/best-channel-for-otp)
- [How does programmable voice work?](https://www.broadnet.me/answers/programmable-voice)
- [What are SMS OTP best practices?](https://www.broadnet.me/answers/sms-otp-best-practices)
- [Voice](https://www.broadnet.me/products/voice)
- [OTP service](https://www.broadnet.me/products/otp)