"Ship Now" orders cannot be manually combined after your order has been placed. However, we will automatically "Ship Now" orders if they are placed within a few hours of each other, or if they have the same shipping method and their items come into stock at the same time.
Any paid items in your Private Warehouse can be combined with each other for shipment.
"Ship Now" and "Private Warehouse" orders cannot be combined. However, if the orders you'd like to combine have not yet been billed, just go to My Account and change their handling methods to "Private Warehouse." This way, you will be charged for the items as they become available, and they will move to your Private Warehouse, where you can then combine them for shipment.
After you have been billed for an order, changes cannot be made.
For more information about making changes to existing orders, please see this page.