Quick credit can be used on both PO and Non-PO invoices. It is designed to make a full reversal of the credited invoice so it's not able to be used in cases of partial credits. In case of partial credit you should be using the corrections button. This gives the option of doing a price correction, quantity correction, or amount correction. Price and Quantity corrections are used for PO matched invoices. A price correction will not affect the quantity billed on a PO as it will only affect the invoice price variance account(best used for price-variance credit memos). A quantity correction will change the quantity billed on the PO(best used for credit memos for returned/rejected items). An amount correction is generally used for non-PO-matched invoices and will simply create the credit memo distributions using the same distributions from the credited invoice.

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