Our subcontractors - like us - calculate cumulative invoices according to HOAI and subtract the advance invoices already made from the total invoice amount in order to determine the outstanding amount. It would be very helpful if we could register sums paid so far. Allocation of the calculated fees by service phases is very complex for cumulative invoices. Since the additional costs and, if applicable, discounts are also calculated on the total amount. Or is there already a solution for this?