While it is a bit inconvenient, though, I don't think it is a bad idea. I am pretty sure it helps a lot making the life harder for people evading taxes, and to some extent the availability of a standard machine-readable format makes it easy to do accounting. My wife sells videocourses online and I developed a thing that automatically issues invoices as soon as people buy a product (with some human supervision, mainly to avoid the machine doing havoc is some exceptional situation happens; normally it is just "click a button to send the invoice"). The invoices are then automatically available to the accountant for doing accountant things.
You can find the XSD here: https://www.fatturapa.gov.it/en/norme-e-regole/documentazion...