If a purchase order has been incorrectly received, you can un-receive the order if required. To un-receive the order, click UnReceive PO from the received order's detail page. The order will be reverted to the Approved state, ready to re-receive correctly or cancel.
If there are stock controlled (FIFO, Batch, Serial) products on the order, this will reverse the stock movements created by the purchase order. Note: If un-receiving the order will put stock controlled products stock on hand into negative, the order can NOT be un-received.