If you need to duplicate an order (create a copy of an order), you can do that as follows:
From the main menu click on Selling » Orders.
Put a check mark next to your order.
Click the Select an Action box in the upper right corner.
Choose Duplicate the Selected Order found at the bottom of the list.
Click Yes on the next box.
Select a Shipping Address for this order. You can choose to have the order shipped to your client or to your location.
Click Duplicate The Order.
Note: This will cause a duplicate order to be created and given a "New" status. Your client will not be charged for the duplicate order.