Here in Sweden we have BankID that is used by every bank and a multitude of other services as an authentication mechanism. It is an app on your phone, tied to your bank account and phone number where you use a passcode (or can enable FaceID on iOS) to basically sign any kind of transaction related to your tax agency number.

It is really how everywhere should be, I need to pay some bills? Add them to my online banking and when I want to send the orders I just need to send them, open the app and sign. Need to send my tax declaration? Login to the tax agency using the app and sign and validate before sending my form. Do I need to validate a payment done with my credit card that was caught and marked as possibly fraudulent (because my purchasing behaviour changed a little bit from the norm)? No worries, just open the app and validate that you are you.

And so on and so forth...