Here in Sweden we've something called Moible Id and Bank-ID.
You register your mobile phone number on bank website (all Swedish banks offer this service) & download your security certificate on your cell phone or computer.
And from now on you can not only send money to any other mobile phone (via Swish [1]) but you can use your Mobile-ID/Bank-ID to login to every Govt/Private website/app.
Almost every company offers login via Mobile/Bank-ID. Guess what? I can sign off my taxes, parental leaves, sick leaves and whatnot just using the same MobileID. I don't create any logins/password on any Swedish websites at all. Transferring money isn't any exception.
[1] https://www.getswish.se/