When a buyer purchases more than one item from you, but has not yet paid for the items, you can combine the items into a single order. Processing as a single order saves you postage costs, and you can pass on these cost savings to the buyer.
To combine multiple items: From the Sold View, click the sales record for one of the items. Selling Manager and Selling Manager Pro automatically determines if there are other items that qualify to be combined into a single order and provides you with the option to combine the items.