There are three different ways to achieve this.
1.Add a Return to Vendor and return the incorrectly priced stock, then repurchase the stock with the correct price.
2.If a return to vendor cannot be added because the stock has been sold, add a negative expense order or an expense order and link to the original purchase order. This will reduce/increase the COGS on the original purchase order. The negative expense order will reduce/increase all the stock records on the purchase order. This will not work if not all the stock requires pricing to be amended.
3.If not all stock records are to be impacted by price fix, add a further negative expense order or expense order to produce either a credit or further invoice in the creditor’s account. The stock on the original purchase order will not be impacted, however the costs on these purchases will not be correct.