The format for an italian IBAN is:
·2 letters ISO country code
2 digits IBAN check digit
1 letter check digit
5 digits bank code
5 digits branch code
12 characters account number
At least that's how it appears on invoices I receive from Italy.
Entering the number in Bunq is hard because the spaces between the sections are completely different. I had to do it three times just now to get it right.
Any Italians in the room can put me straight?