When you make a purchase of goods or services and where there is a delay between ordering the items and the receipt of those items, the details of the purchase should be recorded as a purchase order.
When the items are finally delivered, you should check the pricing against the original order, and enter the quantity actually received. When you “process” this, MoneyWorks will automatically create a creditor invoice, and if necessary update your stock. Any items not delivered will be held as back-ordered items.
If, as sometimes happens, the items are received before you get the invoice, you can receipt the items into stock and process the invoice later.