Verify new users and login attempts with failover SMS & Voice phone verification: 2FA

Phone verification secures your services from misuse. But if done poorly, it can ruin user experience. Build the perfect verification flow with our SMS- and voice-based solutions

Verification products to secure best user experience and protect your Apps

Missed call verification

With this cost-savvy verification technique, users receive a missed call from a random number. The 4 last digits of this random number are used as a passcode.

Strong SMS verification

One-time SMS passcodes are sent via our extensive mobile carrier network to ensure best delivery rates at optimal costs.

Phone call verification

Passcode is delivered as a voice message via phone call, reaching both mobile and landline numbers.

Caller ID verification

Another cost-saver, where the user receives a random phone number to call. They complete verification by dialing this number from the number that needs to get verified.

HLR lookup

Every phone number is verified against international databases to ensure it’s validity and identify the type (mobile or landline).

Multiple carrier support

Connected directly to 120 voice and SMS providers worldwide, Apifonica ensures failover delivery of verification calls and messages at the best rates.

How complex Voice & SMS phone verification works


Phone number validity check

When users enter their phone number for the first time (i.e. during a registration process), Apifonica instantly checks international databases to define if the number is valid and whether it is a mobile or landline number.


Landline number verification

An SMS cannot be delivered to a landline number, so Apifonica converts the passcode into a voice message using text-to-speech technology, calls the user and reads them the passcode.


Mobile number verification

Apifonica delivers verification passcode via SMS. If undelivered or users provide no input, Apifonica calls the number and reads out the passcode.


Passcode input

Users input the passcode to complete the transaction, which is then verified by the company’s system.

Why your business will prefer complex phone verification by Apifonica

Top reliability

We use multiple carrier providers to deliver verification codes. If initial delivery fails, we act instantly to deliver the code via alternative routes.

Incredibly affordable

Voice calls are at least 3-5x cheaper than SMS. With SMS and Voice you build a verification flow that is both strong and affordable.

Best success rate

Even strong passwords are hackable. Complex phone verification via SMS & Voice call provides a second layer of control to eliminate unauthorised account access.

Most complete solution

Apifonica can verify both mobile and landline phone numbers using a mix of SMS and Voice call for one-time passcode delivery.

Our customers build best user experiences with SMS and Voice phone verification


Delly simplifies the sign-up process for new customers using Apifonica SMS verification. To create an account with Delly, users enter their phone number and instantly receive an SMS access password. Delly’s approach allows user verification and grants site access in a single step for a seamless user experience.


Dzinga uses complex SMS and voice call verification to verify new users. When new users sign up, they receive a verification passcode via SMS. If the SMS isn’t delivered in a few seconds, it automatically converts into a voice message to be delivered as a phone call. Complex verification allows Dzinga to verify every user faultlessly.

Why choose Apifonica?

Backend - done!

We provide a ready-to-use backend solution tailored to your exact needs so you don’t need to build it yourself.


Direct connection to 120 carrier networks worldwide results in the highest quality routes at the lowest prices.

Unrivalled support

Dedicated project team providing 360 degree responsiveness and 24/7 availability.

Full GDPR compliance

Apifonica has fully implemented the EU's General Data Protection Regulation.

4 easy steps to success with Apifonica Two Factor Authentication

Step 1

Click below to make contact with us

Step 2

Discover what can we do for your phone verification project

Step 3

Try out free tests for system suitability before launch

Step 4

Be prepared to take your business to new heights

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