How to fix a PO Receipt cost that was entered incorrectly

It's very difficult to fix historical cost transactions that have already occurred and have flowed through other costing areas. You would essentially have to reverse the entire process, each step of the way, back to the source of the problem. Then, correct the source of the problem and re-create everything that you just reversed.

So, for example, to fix the cost of an item that has already been PO Invoiced and Payment Processing applied, you would have to reverse the payment. Then, reverse the PO Invoice. Then, reopen the PO line in question. Then, reverse the PO Receipt of that item. Then, perform the PO Receipt (at the correct cost), enter the PO Invoice and Payment Processing again. On top of that, this gets even more complicated if the mistaken-cost item was already issued to a Job. Then, you're looking at reversing (stepping backward) from potentially a Sales Order invoice, to picking reversals, to Job Receipt reversals, to Job Issue reversals...all the way backward to the source of the problem, basically.

We do not recommend the above process. The main reason is because there's not a lot of benefit in correcting those past transactions. In the accounting (GL) side of the system, these types of mistakes are accounted for appropriately (by booking variances automatically). Instead of this long process without much benefit, our standard recommendation for these types of situations is just to correct *current* data and move forward.

Correcting current data means to review the Inventory Cost of the item in question to see if it seems accurate. If it's wrong, you can always adjust it using (Inventory > Change Inventory Costs). Then, just proceed forward with extra caution when reviewing costs during future PO Receipt entries.