SMS Verify API

The SMS Verify API delivers phone-based verification and two-factor authentication using a limited duration, one-time passcode sent over SMS.


To send SMS messages for other purposes besides delivering verification codes, use the TeleSign SMS API, not this one.

Common Use Cases:

  • Two Factor Authentication (2FA) - Prompt a user, after entering their password, to enter a verification code you send to their phone number to complete a log-in process.
  • Password Reset - Ask a user to enter a verification code you send to their phone number; if they enter it correctly, allow that user to reset their password.
  • Verification - Make sure a user is not entering a fake phone number, by sending a verification code to their phone and asking them to enter it in.

General Requirements

  • Base URL:
  • Protocols: https
  • Authentication: Basic (easiest to implement) or Digest
  • Encoding: Accepts only UTF-8 unicode characters as inputs.
  • Accepts: application/x-www-form-urlencoded
  • Responds With: application/json
  • Required Headers: Content-Type - application/x-www-form-urlencoded

Documentation by Category


An SMPP implementation may be better for you than using the REST API if you need extremely high throughput, but the integration requires a higher level of technical expertise and may take longer.

Other Resources

  • Try It - Use a widget to make some test requests without writing any code.
  • Compliance - Learn SMS compliance best practices from these articles in our Support Center.

Compliance with regulations in some countries may require you to give the end-user a way to reply to your message. To add this feature to your integration, you can use the TeleSign Inbound SMS service.