If you wish to add additional items to an order, the best option is to place an additional order. We regularly check to see if there are multiple orders going to the same address that can be combined, though we cannot guarantee it. If we are able to combine your order, you will be refunded the difference in shipping (if applicable). Please allow 2-3 business days after the order ships for the refund to come through. You are also welcome to contact our customer service team at 385-645-5386 and they will be happy to assist you.