SMS OTP

Verify logins and transactions with SMS OTP

Generate, deliver, and validate one-time passcodes over low-latency carrier routes with configurable expiration times and multi-channel fallback.

Contact SalesGet Started

Build the send-and-check workflow with Verify SMS. For the differences between a delivered passcode and a code generated by an authenticator, read OTP, TOTP and HOTP explained.

SMS OTP

Fast passcode delivery and verification in two API calls

Priority OTP routing. Route verification codes over direct carrier connections across 190+ countries so users can complete sign-in and checkout before codes expire.

Managed code lifecycle. Generate one-time passcodes, enforce expiration windows, and limit verification attempts through the Verify API without storing plain-text codes in your database.

Registered local senders. Deliver OTPs from pre-registered alphanumeric sender IDs, short codes, toll-free numbers, or local numbers to reduce carrier filtering.

Voice and WhatsApp fallback. Automatically retry undelivered SMS passcodes over text-to-speech Voice calls, WhatsApp, or Email so users are not locked out.

Frequently Asked Questions

How quickly are OTPs delivered?

Bird routes OTP traffic over priority carrier paths so time-sensitive passcodes arrive within seconds during sign-in or payment confirmation.

How does Bird's Verify API handle code validation?

Call one endpoint to generate and send the passcode, and a second endpoint to verify the code entered by the user. Bird enforces TTL expiration and attempt limits automatically.

Can I customize OTP message templates?

Yes. Customize your sender ID, message copy, language, code length, and expiration window to match your brand and platform autofill formats.

What delivery rates can I expect?

Bird achieves 99% delivery rates across direct carrier connections and provides per-attempt delivery status codes.

How do you handle failed SMS deliveries?

Track delivery receipts in real time and configure fallback rules to resend the passcode via Voice, WhatsApp, or Email if the SMS does not arrive within your timeout window.

Can I integrate SMS OTP with my existing auth system?

Yes. You can either use the Verify API to manage code generation and checking, or generate codes in your own identity provider and send them through the SMS API.

Put it into practice.

Continue with the documentation, guides and examples for this topic.

Watch the guideVerify phone numbers at signupImplementation guideVerify your first customerUnderstand the conceptWhat does OTP mean? One-time passwords explainedFollow the learning pathBuild your first integration
Try the practice and get an implementation brief

Start building with Bird in minutes.

Get StartedContact Sales