Mobile Number

Mobile Number is a field type dedicated to mobile numbers. There are several reasons for using a dedicated mobile number field, as opposed to using the more general Phone module, which are as follows:

One number, One person

Landline numbers can belong to a whole office or home to which a call may not lead to the same person every time. Most mobile numbers however belong to a mobile device which is carried by a specific person. This guarantees that mobile numbers will always lead to one individual to which the number belongs. This allows to differentiate personal numbers from general purpose phone numbers.

Verifiable

Thanks to the sms capabilities inherent to all mobile numbers, a textual verification code can be sent to the number which allows verifying number ownership, as well as validating by the user that the number provided is correct. This adds a layer of validation which will guarantee a number is callable and that it belongs to the user. And, as a result, it can also be used as anti spam bot protection.

Two factor authentication

Similarly to the point mentioned above, a one time access code can be sent to the user to be entered during login, which adds another layer of security, also known as two factor authentication, where the first factor is checking something a user knows (a password) and the second factor is checking something a user owns (a mobile number). This is a popular method on the web for adding additional security to user accounts.

Mobile user identifier

Because of the advent of smartphones, today most mobile numbers belong to a smartphone. Because of this, site builders can assume smartphone capabilities (eg. iOS or Android) when a user supplies their mobile number. This works well when developing smartphone apps that integrate with a drupal backend, where a mobile number alone can identify a mobile user, a method used by popular apps such as WhatsApp.

SMS capabilities

In addition to verification and two factor authentication, sms has many other uses, especially when used with smartphones. Links can be sent and opened in a mobile browser, essentially replacing the use of emails, which is especially useful since SMS has higher delivery rates than email (90% of sms are read within the first 3 minutes of sending them). And SMS can also be used like notifications when used in combination with the Rules module. So a Drupal site can work well with smartphones, with or without a mobile app.