It kind of sounds like a bug. At this point, you'd have to edit the files (poordlin, polinhst & imrechst) to remove the links to the voucher you've voided & the receiver. You can negatively receive the amount of inventory at the wrong price. Then you can probably re-voucher using the correct invoice amount. Hard to test as all versions behave slightly differently. You could also just voucher & "over invoice", but some versions would show this difference on the received not invoiced report. One of the odd things about the macola ap/po interface is that it is real time. SOOOOOOO, even though ap is a batch process for vouchering & posting, when you match the receiver to the ap invoice in the second screen, the po line file is updated for amount received, even before you post your ap batch. Depending on how you get out of the ap voucher, it may or may not remove the entry from the invoiced amount in po if you decide to abort the voucher.