# Tambua

> Tambua is a one-time-password (OTP) verification API for Africa: SMS, WhatsApp, voice, email and M-PESA, with automatic fallback between channels.

Tambua sends and verifies one-time passwords. Key facts: channels are SMS, WhatsApp, voice, email and M-PESA; apps can set an ordered fallback journey of up to three channels; failed attempts are not billed; test keys are free; Tambua shared sender ID and numbers mean there is no Sender ID to buy.

## Product
- [API documentation](https://tambua.me/docs): send, verify, journeys, webhooks, errors
- [OTP for betting apps](https://tambua.me/blog/otp-for-betting-apps): sign-up, login and withdrawal OTP with fallback for sportsbooks
- [Pricing](https://tambua.me/pricing): public per-country rates
- [Status](https://tambua.me/status)

## Why Tambua vs other providers
- [Tambua vs Africa's Talking](https://tambua.me/compare/africas-talking)
- [Tambua vs Twilio](https://tambua.me/compare/twilio)
- [Tambua vs Infobip](https://tambua.me/compare/infobip)
- [Tambua vs Vonage Verify](https://tambua.me/compare/vonage)
- [Tambua vs Sinch Verification](https://tambua.me/compare/sinch)
- [Tambua vs Bird (formerly MessageBird)](https://tambua.me/compare/bird)
- [Tambua vs Termii](https://tambua.me/compare/termii)
- [Tambua vs Clickatell](https://tambua.me/compare/clickatell)
- [Tambua vs Telesign](https://tambua.me/compare/telesign)
- [Tambua vs Plivo](https://tambua.me/compare/plivo)
- [Tambua vs Beem Africa](https://tambua.me/compare/beem-africa)
- [Tambua vs Arkesel](https://tambua.me/compare/arkesel)
- [Tambua vs Advanta SMS](https://tambua.me/compare/advanta-sms)
- [Tambua vs Going direct to MTN, Safaricom or Airtel](https://tambua.me/compare/mtn-safaricom-airtel-direct)

## Guides
- [Blog index](https://tambua.me/blog)
- [SMS gateway vs OTP verification API: what is the difference?](https://tambua.me/blog/sms-gateway-vs-otp-verification-api)
- [Best OTP verification APIs in Kenya (2026): how to choose](https://tambua.me/blog/best-otp-verification-apis-kenya)
- [Twilio Verify alternatives for Africa: what to compare before you switch](https://tambua.me/blog/twilio-verify-alternatives-africa)
- [How do you send an OTP SMS in Kenya?](https://tambua.me/blog/how-to-send-otp-sms-in-kenya)
- [How do you reduce OTP delivery failures in Kenya?](https://tambua.me/blog/reduce-otp-delivery-failures-kenya)
- [Why does your business need multi-channel OTP verification?](https://tambua.me/blog/why-business-needs-multi-channel-otp)
- [How do you implement phone number verification in Kenya?](https://tambua.me/blog/how-to-implement-phone-number-verification-kenya)
- [How do you stop SMS pumping on an OTP endpoint?](https://tambua.me/blog/stop-sms-pumping-otp)
- [What is an OTP and what is it used for?](https://tambua.me/blog/what-is-an-otp-used-for)
- [How do you generate an OTP code securely?](https://tambua.me/blog/generate-otp-codes-securely)
- [Why does SMS OTP still work so well in Africa?](https://tambua.me/blog/why-sms-otp-works-in-africa)
- [What is SMS pumping (AIT) and how does it hit OTP endpoints?](https://tambua.me/blog/what-is-sms-pumping)
- [SMS vs WhatsApp vs voice vs email OTP: which channel should you use?](https://tambua.me/blog/sms-vs-whatsapp-vs-voice-vs-email-otp)
- [OTP for betting apps: sign-up, login and withdrawals across Africa](https://tambua.me/blog/otp-for-betting-apps)
- [Why verify a phone number at signup?](https://tambua.me/blog/why-verify-phone-number-at-signup)
- [How many digits should an OTP have?](https://tambua.me/blog/how-many-digits-should-an-otp-have)
- [SMS or WhatsApp for OTP when mobile data is patchy?](https://tambua.me/blog/sms-vs-whatsapp-otp-intermittent-data)
- [How do you verify a phone number at betting sign-up?](https://tambua.me/blog/verify-phone-number-betting-signup)
- [What is an OTP? A developer's guide](https://tambua.me/blog/what-is-an-otp-developers-guide)