And I love that requirement. I do banking on my desktop and to confirm the transfers I get a push notification from a third-party application (ItsMe, so not a banking mobile app) with all the information I have entered.

I can confirm the transaction from a complete separate device while doing a second check if all details are correct.

The requirement per se is not the biggest problem. Implementation by different banks is. In my country I have several bank accounts.

One bank allows me to install mobile app on up to 5 smartphones, all I need is connect the smartphone to the Internet (e.g. through Wi-Fi).

Another bank allows me to have up to 3 smartphones, but identifies them by phone number, so it forces me to have 3 difrerent SIM cards

Yet another bank will only allow me to have mobile app only on one device. To activate on another device I need to receive SMS code, and if I lose my SIM card I need to show up at a branch in person.

And that's to say nothing about what happens when changing phones...

Plus the "app" was written by clowns and doesn't really work for any reasonable idea of "work".

Although to be fair this EU requirement tends in practice to make things yet still more cumbersome - requiring multiple authentications in one online banking session.

Oh, so that's why some services have separate codes for login and transacting. Didn't know it was an EU regulation.

Still better than in-house crap.