I am sure that one day all private information is going to be saved uner one private number. Everything: the ID, wallet, phone, insurance end ect. Maybe in 50 years or early this future will became our present.
That time is not much far. Already a lot of things are connected with mobile numbers and can be controlled with mobile numbers. And it will not be much difficult thing and programmers will be able to make this happen. And let me tell you that transferring money using mobile numbers is already somehow practical. In my country there are companies that have given this feature to its users that they can send money from one place to another using mobile numbers.