Verifying users’ phone numbers during on-boarding secures your user base, reduces fraud, and limits duplicate signups. Properly verifying users is therefore important and will impact your business in a variety of ways. However, like any process, sometimes verifications fail. Sometimes a user’s failure to pass the verification process is a good thing if they are attempting fraud or are a bot. However, verification failure can also result from simple mistakes on either your end or the user’s end. You want these mistakes to be the exception and, the norm, and this article details how to accomplish that.

The first step to limiting unwanted verification failures is understanding why these unwanted failures may occur:

User Error

Everyone makes mistakes, including your users. Therefore, ensure that user errors will not limit your ability to verify onboarding customers. This means paying attention to formating and typos while ensuring clarity and opportunities to reattempt the process after a mistake is made.

  • Formatting – Provide your users with detailed instructions on how their phone number must be formatted. Providers want numbers in e.164 format, which includes a country code and no leading zeros. Check out RingCaptcha’s normalization feature for help with phone number formatting. For example, our Authr widget will auto-correct common input mistakes by using a ‘0’ prefix for international number.
  • Typos – Always display the number being verified on the screen. It’s very easy to tap the wrong number during a speedy input. Displaying the number and enabling a “Back” button will give your users the opportunity to correct their own input errors. Again, if you are importing a widget or third party platform for verification, these third parties should cover these bases for you by making their services “typo proof”. For example, RingCaptcha sends a link along with a PIN. That way, users can either enter the PIN or simply click the link if they are running into any trouble.
  • Clarity – PIN codes need to be clear and identifiable without requiring the user to leave your app when opening up an SMS. The more seamless this process is, the lower the signup friction, the better the user experience, and therefore the less mistakes that will come from their end.
  • Multiple Attempts – In the event that a user didn’t receive an SMS or voice call and reattempts the verification process, a best practice is to allow a second attempt. Ideally, you want to have the user wait at least 30 seconds before re-attempting. This is in case the end user’s phone had poor coverage at the time the first SMS was sent. 

RingCaptcha’s fallback feature allows you to automatically send a second verification message, through SMS or voice, either 30 or 60 seconds after the first SMS, should the end user not verify with the first SMS. RingCaptcha further increases the chance of the end user receiving the SMS and converting, by sending the follow-up verification message through another provider, and hence a different route.

International Travel

Users may switch out their SIM cards for international coverage when they are traveling abroad. In the event that a user is attempting to verify his or her phone number with a SIM card other than the one registered to their device, they will receive a verification failure and will be unable to login/signup.

Provide users with any information or requirements affecting verification. If the number is not working, you can then share an easy to understand failure reason with your user. The more the user knows, the more likely they are to retry and be successful second time around, either immediately or at a later date.

Not having a backup in place

Having a backup verification plan in place is important for a number of reasons.

Sometimes providers and their routes have issues. If you’re only connected to one provider, this can cause headaches for both you and your customers. Here at RingCaptcha, we’re connected with over 10 providers, so if one provider is having issues, your traffic is automatically routed to the next best provider for each route.

As we already mentioned, sometimes people lose service, which results in the SMS not reaching the device. Other times, the wrong number is input by mistake which also prevents the SMS from reaching the intended device. Providing users with a backup method to complete verification can help to increase your success rates and account for any unforeseen failures. Voice verification, which places a call to the user asking them to press a digit (or digits) to confirm verification, is a great example. If the digit/s is pressed, your backend is notified that the user is verified.

If you have any questions or any thoughts about ensuring phone call verification is successful, feel free to comment below or message us in our live chat 🙂


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