Verify Automatic SMS Fallback Overview

(information)

Info

Verify Automatic SMS Fallback is currently in the Pilot maturity stage, please contact sales to request access to this feature.

Setting the channel parameter to auto will attempt a verification using Silent Network Auth (SNA) with a fallback to SMS if needed.

SNA is a very secure authentication channel that uses direct carrier connections to verify the possession of a phone number without requiring user input. However, SNA cannot be used in some cases due to carrier or network restrictions. Automatic Channel Selection works by proactively checking if an end user's IP address can support using SNA. If it doesn't, or if other restrictions or errors in the SNA process exist, the SMS channel is used as a back-up.

Learn more about how to implement Automatic SMS Fallback.

device_ip parameter

It's strongly encouraged to include the device_ip parameter when using Automatic SMS Fallback. It is used to preemptively determine whether or not SNA will work for a given device.

To get a device's IP address, we recommend sending a hit from the device to the server to let the server determine the public IP address rather than getting the local IP address from the device directly. The public IP address allows Verify to assess its connectivity and if a device might be using a dual SIM.

Recommended mobile app UX flow

Display an input to the end user with a prompt to enter their phone number, including a disclaimer indicating that text messages may be received to that number.
Display a loading screen while the application calls the Start New Verification endpoint using the auto channel.
Application checks the response for the channel property to see if sna or sms was used.
If sna was used: Stay on the loading screen until the result of the SNA verification is known.
If sms was used: Display an input to the end user with a prompt to enter the verification code, including a message that the verification was sent via SMS.

Future state

The Verify team is working on adding more features to Automatic SMS Fallback with the goal of further improving onboarding conversion, reducing the number of latency-creating API calls, and reducing development burden.

Future features and benefits of this could include:

Additional Fallback Channel Support: While we recommend Silent Network Auth (SNA) as the best phone number verification method, it sometimes isn't available due to a lack of carrier coverage. Verify could add fallback to additional channels beyond the current Automatic SMS Fallback.
Personalized Verification: Across billions of historical Verification events, Verify could identify patterns to predict and personalize the verification method that is most likely to succeed for a given user.
Cost Optimizer: The cost to send a message can be very different and frequently changes across countries and delivery methods. Verify could automatically take this into account when optimizing for the lowest cost onboarding conversion.

If you're excited about these potential features, complete our interest form and we'll be in touch!