End-User Verification

SMS Verify API

An API that enables SMS messaging for account security and business critical communications.

Secure and Engage Your User Base

Ensuring the validity of your users is extremely important in preventing fraud. A great way to do that is to attach a verified phone number to end-user accounts, ideally when they first register. From there, communicate more effectively and provide timely, personalized information in the form of text-based alerts, reminders, notifications, invites and other automated messages.


Connects directly to hundreds of carriers around the world and employs a waterfall approach across multiple routes to help ensure the highest delivery and conversion rates.


Verifies users in real time by sending a one-time code via SMS that can be used to authenticate a known user, verify a transaction or block fraudsters from opening illegitimate accounts.


TeleSign sends an SMS with an OTP along with transaction details, and the user then replies with the code and approves or denies the request.
* Two-Way Communications feature is not available in all markets. Contact TeleSign for specific availability.


Separates SMS message over 160 characters based on device type and operator requirements and sends it to the user’s handset with instructions to reassemble the message back in the correct order as one SMS.


When splitting a long SMS message, it prevents the breaking of critical pieces of information, such as urls and email addresses, to ensure messages are delivered and viewed as intended.


Properly formats phone number entered by end-user to ensure greater global delivery.


Helps ensure message delivery to end-users in more than 200 countries and territories in 87 languages.


Prevent Fake Users

Mitigate new account registration fraud and attempts at bulk account creation.

Protect Account Access

Seamlessly authenticate existing users and secure accounts from compromise.

Reach & Engage More Users

90% of texts are read VS. email at 20%.

Developer Friendly APIs

Easy to test, integrate and get up & running quickly. Clear documentation, developer center and reporting.

We were looking at several vendors, but TeleSign won out because of their demonstrated security expertise, the quality of their global SMS authentication offering, and because they understood the importance of the overall experience. TeleSign worked closely with us to ensure our UI/UX provided the best experience possible and would be easily adopted.

Dave Engberg, CTO, Evernote

How It Works

The following is one example of how to use the product to verify the identity of a user attempting to access their Web account from a new device.

The user visits your website and enters their existing credentials (username and password) to access their account.
The user already provided a verified mobile phone number when they first registered for an account.
Because this is the first time the user is accessing their accountfrom a new device, a challenge is needed to further verify the user and permit them to complete the login attempt.
SMS Verify sends a time-based one-time passcode to the user’s mobile number and at the same time, the user is shown a secondary login screen in their Web browser with a prompt to enter the passcode once it is received.
Once the user receives the passcode to their mobile device, they simply enter it in on the webpage as prompted.
You confirm with TeleSign that the passcode entered is the same code that was sent to the user and, if matched, the user is verified.
The user is then able to access their account.

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