We use your phone number as a way to distinguish each user. Aka: a phone number = a user. The phone number also allows us to verify your account and offer an extra level of security.
Don't worry. We won't call you unless you ask us to. :)
Your virtual card will continue working even if you don't have your device, although we recommend that you download the app on your new device and login as you normally would.
If you have any problems or have changed number, contact us via chat or write to firstname.lastname@example.org and we'll help.