When you order one or to flats we ship each flat with the USPS Flat Rate Large Box. The shop is set up for that pricing. However, if you want more flats it might be cheaper to send them together using UPS or FedEx. But we will not know the pricing until we know the order and go with the weight and size to the shipping company. In that case we will contact you regarding shipping and adjust the price accordingly before sending anything out. We will also contact you before shipping if you order from Canada.