Your banks are slow. Many process SEPA transfers a lot faster than that, try N26 to Revolut if you're curious.
Also the SCT inst scheme has started being rolled out.
Also the SCT inst scheme has started being rolled out.
edit: also, those banks are UK ones. I'm not inclined to open accounts there with Brexit going on. Foreign accounts are also a pain for tax admin.
On another level, why should the state have a list of my accounts at all? It already sees all the accounts at banks within their territory. They don't need to concern themselves with accounts outside their jurisdiction.
In the context of income taxes, it should be enough to report total earnings, regardless of which specific account holds them.
Yes, the SEPA scheme is old and working only during business days according to the TARGET2 calendar, but you definitely can process a transfer within a couple hours (my online stock broker does).