An order can only be cancelled if it has a "Confirmed" status, and doesn't have any invoices or receipts linked to it.
If you select multiple orders and some of those order cannot be cancelled, e.g. if they are not confirmed, you'll see a message listing the orders that cannot be cancelled and asking if you wish to proceed with the cancellation of the others.
Cancelling multiple orders will still generate a single notice per order.
If a reservation is placed against the order in Acquisitions, or against a title that only has 'on order' holdings then the reservation(s) will be cancelled automatically if the order is cancelled.
You might want to cancel an order because it is no longer required or if it has been cancelled by the requestor. Or perhaps after the order has been confirmed and the PO dispatched, the vendor advises you that the item is no longer available for purchase.
To cancel orders from the Order List:
To cancel orders from the Purchase Order List: