Phone Number Verification API

Delivers patented phone-based verification and two-factor authentication using a time-based, one-time passcode sent over SMS or voice message.

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Establish a global trust anchor and verify users with any phone type

Ensuring the validity of your users is extremely important in preventing fraud and securing accounts from compromise. By attaching a verified phone number to an end-users' account that users' identity can easily be confirmed when they access their account from a new browser or device or attempt a high-value transaction.


Strengthen Authentications & Reduce Fraud

Instant API access to ongoing and accurate key phone number and user identity data attributes to help make better decisions about new registrations, user activity and fraud risks.

Verify Transactions

Seamlessly authenticates users as they make account changes and high-value transactions such as accessing credit card details, transferring funds or making bill payments.

Protect End-User Accounts

Secures accounts from compromise using voice-based OTPs on any phone type, on a global scale.

Prevent Fake Users

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

Reach Landline Phones

Enables global reach of users who do not wish to receive SMS-based messages and/or provided a number that is not equipped to receive them.

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We needed a partner that could scale to support our ever expanding global footprint. TeleSign delivered the scale we were looking for.

Chuck Mortimore

VP, Product Management, Identity, and Security, Salesforce

How We Verify

High Quality, Direct-To-Carrier Routes

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.

Secure, Time-Based, One-Time Passcode (TOTP)

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.

Reliable Global Coverage

Provide the most coverage and ensure message receipt and delivery to users in 87 countries and territories. Make sure your users are connected, wherever they are.

Inbound SMS For Interactive Two-Way Communications

Send and receive global text messages to listen, engage and provide support to customers. *This feature requires an additional transaction fee and is not available in all markets. Contact TeleSign for specific availability.

Call Forward Detection*

Checks in real-time to determine if a phone number is being diverted via call forwarding to allow you to then block, allow or require additional user challenges for verification. *Check with your sales representative for availability in your area.

Fraud Risk Scoring + IRSF Prevention

Perform fraud risk assessments before sending voice messages to identify and block high-risk phone numbers, phone types, countries, prefixes and number ranges. Effective method for stopping or minimizing International Revenue Share Fraud (IRSF) attacks and bulk account creation. *This feature requires additional fees. Contact TeleSign to enable this optional feature.

Talk To An Expert

Interested in learning about how TeleSign's identity and engagement solutions can prevent fraud while fostering secure and global growth for your business? Let's chat.