USPS

The United States Postal Service (USPS) remains the only carrier with the mandate and infrastructure to reach every address in the nation, making it an indispensable partner for ecommerce merchants. From residential mailboxes to P.O. Boxes and military addresses, USPS offers unparalleled reach. For online retailers, it is frequently the most economical choice for lightweight parcels (under 20 lbs) and offers reliable speed through services like Priority Mail Express and the consolidated USPS Ground Advantage™.

For high-volume merchants, the UltraCart integration goes far beyond simple label printing. We support advanced shipping configurations that scaling businesses require, such as Electronic Verification System (eVS) for bulk manifest processing and Permit Imprint capabilities. This allows your warehouse to move faster, processing thousands of orders without the friction of individual postage metering, ensuring your fulfillment operations scale smoothly alongside your sales volume.

The synergy between UltraCart and USPS is built for precision and margin protection. Unlike generic plugins that often estimate rates poorly, UltraCart's deep integration handles complex rating logic—including dimensional weight and regional rate boxes—to ensure you (and your customers) are charged the correct amount every time. With native support for the new USPS Ground Advantage, UltraCart ensures you are utilizing the most modern, cost-efficient service tiers available immediately upon their release.