Verify User Logins with Two-Factor Authentication.

Enhance application security & manage user verification via SMS & phone calls with CM's two-factor authentication (2FA) API.

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What Is Two-Factor Authentication (2FA)?

Two-factor authentication is a security method that helps businesses prevent attacks and hackers from accessing online services, apps, data, and systems. A 2FA app adds a second factor beyond username/password, requiring the use of personal mobile devices such as a "key” to verify a user’s identity.

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The Benefit of Using One-Time Passwords (OTPs) for 2FA

Online security and data protection are key priorities for digital businesses. Two factor authentication is an additional layer of security to overcome the vulnerabilities of standard password access.

A one-time password is an easy and highly reliable form of 2FA. OTPs drastically reduce the risk of fraud by sending users a time-sensitive, unique, and random code/PIN to their mobile device via an SMS, call, or Push message.'s 2FA API generates highly-secure OTPs & provides the connection to validate & match unique OTPs with users linked to a specific system or device.

  1. Guaranteed Delivery's One-Time Passwords can be delivered via SMS, Voice Call, or Push message. By choosing or combining both channels, you can guarantee fast and reliable delivery.

  2. API Integration

    With the Two-Factor Authentication API from, you can generate One-Time Passwords, deliver them via SMS, Voice, or Push and verify the response.

  3. All-in-One Platform also offers SMS and Voice that enable a variety of other solutions beyond sending and receiving OTPs. Joining gives you access to all of our mobile products and solutions.

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Comprehensive Solutions for Two Factor Authentication

Quick Delivery of OTPs via SMS or Voice

Authenticate Your Users

Ensure that all users who attempt to access your system from a new or existing device verify their identity. Prevent suspicious logins, spammers, or bots from accessing your platform.

Secure Account Logins

Protect your accounts from data theft and suspicious users. Reinforce your system’s security at every login attempt and automate the delivery of OTPs via SMS, voice, or push notification.

Safeguard Transactions

Add an extra layer of security by prompting users to enter their OTP to verify accounts and identification before they’re able to proceed with a transaction.

Deliver One-Time Passwords via SMS

With an average open rate of 98% in under 30 seconds, SMS messages are known for being highly reliable. Using SMS helps ensure your OTPs are optimized to reach your users wherever they are. 

SMS is a great channel for OTPs and can still be sent without an internet connection.

  1. Number validation

  2. Fast and reliable delivery

  3. Send from a local phone number

  4. Automatic fallback via voice call or push

Start Sending SMS OTPs - 2fa solution - send one-time password via sms - phone image

Deliver One-Time Passwords via a Voice Call

Voice is an alternative to OTP SMS. With Voice, the spoken password is received as a phone call on the user's mobile device. The password will not be stored on the user's phone and Voice allows you to reach users with limited sight. You can also implement Voice as a back-up in case your SMS is not delivered.

  1. Global reach and reliability

  2. Various language/speaking options

  3. Close to 100% delivery rate

Start Sending Voice OTPs 2FA solution - one-time password voice call / message image

Why Use a 2FA Authenticator App?

Two-factor authentication minimizes the risk of fraudulent login attempts and comes in all shapes and sizes, but always adds an extra layer of authentication. The risk of fraud is drastically reduced if the user doesn’t only need to fill in a username and password (something they “know”), but also needs something they “have” to complete the login.

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Customer Success & Use Cases provides high-quality and reliable 2FA technology and services for companies of all sizes. Learn how our 2FA API enables easy, secure and safe access and logins for both consumer and seller.

OTP for Developers:
Easily Integrate our OTP API offers a reliable and secure One-Time Password solution that can be delivered to any mobile phone via Voice or via our reliable high quality SMS routes. Our OTP solution builds consumer trust and increases security across multiple channels.

Use one ready-made API to implement into your software and offer intelligent and secure OTP authentication to protect your users and your data. Use our developer documentation and send your OTPs worldwide.

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Why Choose

GDPR-Compliant Enterprise Messaging

Worldwide Delivery Under 10 Seconds

Our proactive monitoring guarantees fast delivery of time critical messages in high volumes. Delivery rate and speed is constantly measured by live test results.

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Direct Mobile Operator Connections

Our platform is connected to 2000 operator networks in 200 countries. This means that you can benefit from high quality routes at the best price.

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Secure and Reliable, 24/7/365 Support

With high uptime and a redundant setup, you can rely on our highly secure and ISO 27001 certified platform with 24/7/365 support from our Network Operations Center.

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Real-Time Analytics, Detailed Insights

Our powerful Analytics tool gives you a real-time and detailed overview of your worldwide traffic so you can track, trace and optimize flows.

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