MMS Messaging - deliver messaging experiences with images and video


Phone verification 

Phone verification is the process of verifying whether a specific phone number belongs to the person associated with a customer or user account. The process consists of a few different components and sub-processes. Read on to find out more!

What is phone verification?

Phone verification is defined as any of the processes involved in verifying the validity and availability of a number, or the identity of the phone number user.

Numbers can be verified in real-time by checking records in operator home location registries (HLR). These checks can provide detailed number status information – but the most important is whether the number is a valid one. Armed with this information, businesses can decide whether to engage in more in-depth verification.

In-depth verification methods involve user interaction. An example of verification requiring user interaction is common 2-factor authentication.

When signing up for a service, users will be sent a one-time PIN code to their number which they enter when prompted. This can serve as evidence to the service provider that the number is valid and that the device associated with the number is in the user’s possession.

OTP codes are most commonly associated with SMS messages. But there are various channels that businesses can use to ensure prompt delivery of verification codes, including:

  • Voice – this is often the channel of choice for accessibility
  • RCS
  • Chat apps – WhatsApp, Viber, Zalo, KakaoTalk

Another method, and one that doesn’t require user interaction, is silent mobile verification, which works by cross referencing the number with mobile operator data.

This process doesn’t require any effort from the user other than consent – which is great for user experience. In addition to verifying the number, silent mobile verification can be used throughout the customer journey to authenticate actions. Additionally, silent mobile verification can be used as an added layer of security to check whether the SIM card is still in the device. A missing SIM card could be indicative of SIM swap fraud.

This brings us to SIM swap check, which further enhances number verification security. SIM swap check looks at operator records to see when the last MSISDN was paired with the IMEI­. This is a step that helps ensure the user phone number and device are paired.

Why is number verification important?

Number verification is important since collecting and maintaining accurate customer contact databases is a basic requirement for any business looking to build and nurture lasting customer relationships.

If providing positive customer experiences is important to your company – then number validation should be, too.

Because your outreach is only as good as the information in your databases. By checking numbers in real-time at common customer entry points, you can be sure that every message you send customers will hit the mark – and save yourself the costly embarrassment of providing poor customer experience.

Ensuring a valid and verified number is attached to a customer record also helps properly identify customers throughout the customer journey. This helps businesses provide personalized, contextual customer service.

But verifying numbers is important for more than just providing smooth customer experience and personalized interactions.

Number verification can be used to boost security and keep you and your customers safe.

Businesses can protect their customers and themselves by requesting customers to authenticate actions in real-time for important transactions, i.e., cash withdrawals from ATMs abroad or account sign-ins from different geographic locations.

And of course – there’s cost. When businesses target large databases of numbers, they can reduce their overall costs by using number verification to target only numbers that are available. This helps to avoid the costs associated with messaging any invalid or inaccessible numbers.

From providing contextual customer experiences to cost optimization and boosting security for you and your customers, number verification is a must-have. But how do you get started?

How to do number verification

There are several ways to perform number verification. The fastest way to perform number verification in real time is using Number Lookup. This is an HLR-based check that verifies number validity against live operator records.

Number Lookup

When a customer enters their number, your system sends a request through a service provider and checks the number status against operator records. The results can indicate whether a number is correctly formatted, active, reachable – or simply invalid.

These checks can also be performed throughout the customer journey. For example, when making a withdrawal from an overseas ATM, it’s prudent to perform a check on the customer’s number to ensure their device is attached to a mobile network in that country.


Next is number verification via OTP. Once you’ve performed a check and found the number valid, you want to verify that it belongs to the customer.

Depending on the customer’s preferences, you can send them an OTP via SMS or RCS, as well as over chat apps like WhatsApp, Viber etc.

Silent mobile verification

When the customer receives the one-time pin code, they verify ownership and possession of the number by entering it when prompted.

You can continue performing number verification checks throughout the customer journey in an unobtrusive way with silent mobile verification. Silent mobile verification checks the number in the background, ensuring the user’s identity.

By verifying customers in the background, you keep them secure while also providing uninterrupted customer experiences.