In the taxiID Driver app you are visible with your driver phonenumber. You can customize your phonenumber in your taxiID profile.
You can find your profile by loggin in through http://www.taxiid.eu/login. You can log in with your email address and password. You can request a new password here if you have lost it.
You can change your phonenumber in the drivers information via the menu Accountdetails / drivers / select driver / edit.