USPS

USPS is one of the most popular solutions for shipping in the United States. Just like UPS, they too offer real time costs for shipments based on the warehouse location and the ship-to address.

Click here to register with USPS' Web Tools.

Note that you will need a separate USPS user ID for each web site as per the terms and conditions of use.

Administrative Steps

To use the USPS APIs you must be a registered user. If you have not registered, go to  http://www.usps.com/webtools/  and follow the instructions to register for the APIs.
Upon completion of the registration process, your user ID will be sent via e-mail to the address specified in the registration. You will be immediately granted access to the production server for our price calculators, package tracking, address information and service standards and commitments APIs.