Please help me on this scenario: my client makes an advance payment for a PO and receievs an invoice for that. This invoice has VAT and it is shown at the VAT report. After a while the vendor sends the materials and a final invoice with the difference of the invoice minus the advance payment. The problem is that my client wants to post the invoice with the difference so as to have the correct VAT on the report, but in MM we have to post the hole ammount so as not to have differences with the PO. Please give me a solution how to treat the advance payment invoice.