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.

You can either generate the verification code yourself or have TeleSign generate it for you. You can also optionally screen verification SMS recipients by risk score or SIM swap risk indicator. You also have the option to configure your verification codes to expire after a set duration of time or after a max number of attempts by an end user.


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.
  • Login 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.
  • Payment Verification - Verify a payment with Strong Customer Authentication (SCA), as part of compliance with the European Union’s Revised Payment Services Directive (PSD2). This use case is relevant to fintechs, open banking solutions, payment service providers (PSP), and e-commerce platforms.

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.