Filling in a phone number during registering your Zaurus account has three purposes.
First of all, it is an extra form of authentication. When you have filled in a phone number during registration you receive an SMS token. With this your company can be assured you are not using a so called ‘catch-all’ email account.
Secondly, your Zaurus app checks your phone book at a certain interval. It does this to see whether any of the contacts in your phone book are currently using Zaurus. These contacts can be found by entering their email address or their phone number. If you have filled in your phone number during registration, your professional contacts can find you using your phone number as well.
Thirdly, when you are working for multiple organizations, you can register different Zaurus accounts for each of those companies. If you have registered your accounts using the same phone number, you can merge these accounts.
At this time, filling in a phone number during registration is not required. However, it is possible for your organization to make entering a phone number obligatory for all team members.