USPS The United States Postal Service (USPS) is often the least expensive choice out of the three main carriers. Following that, United Parcel Service (UPS) comes in at a close second, while FedEx is ranked as the most costly carrier, despite being undoubtedly the most dependable. The United States Postal Service (USPS) is the most often used shipping option for small businesses because it provides the optimal balance of price and service.