Introduction
The USPS Web Tools Application Program Interfaces (APIs) allow developers of web-based and shrink-
wrapped applications access to the online services of the United States Postal Service (USPS). They
provide easy access to shipping information and services for your customers. By integrating these APIs
into your web site, your customers can utilize the functions provided by the USPS without ever leaving
your web site. Once the APIs are integrated into your website, the USPS Shipping API Server
communicates over HTTPS using XML (Extensible Markup Language).
Implementing these APIs requires experienced programmers who are familiar with Internet and
web site development tools and techniques.
This document provides guidance and step-by-step instructions for installing the USPS APIs, as well as
fulfilling various administrative requirements. The administrative requirements vary between different APIs
(e.g., submitting samples of labels for some APIs, signing a licensing agreement for certain software,
etc.), and this document provides guidance to navigate through the process for the API you are
implementing. It is imperative that developers read this manual first, as it provides necessary information
and procedures prior to use.
There is a Web Tools User’s Guide for each API available at http://www.usps.com/webtools/. These user
guides provide information of the XML transactions to the USPS Shipping API server.
User ID Restrictions
The user ID that you have received is for you or your company to use in accordance with the Terms and
Conditions of Use to which you agreed during the registration process. This user ID are not to be shared
with others outside your organization, nor are they to be packaged, distributed, or sold to any other
person or entity. Please refer to the Terms and Conditions of Use Agreement for additional restrictions on
the use of your user ID, as well as this document and the APIs contained herein.
Warning: If the U.S. Postal Service discovers use of the same user ID from more than one web site, all
users will be subject to immediate loss of access to the USPS server and termination of the licenses
granted under the Terms and Conditions of Use.
The documentation and sample code contained in the Web Tools User Guide series may be reused
and/or distributed to your customers or affiliates to generate awareness, encourage Web Tool use, or
provide ease-of-use. However, it is your responsibility to ensure that your customers do not use your user
ID. Direct your users to www.usps.com/webtools/ so that they can register, agree to the Terms and
Conditions of Use agreement, and receive their own unique user ID.
Note to Software Distributors: The user ID restrictions discussed above are intended for e-tailers that
use the USPS Web Tools exclusively within their own web sites. If you plan to distribute software with the
USPS Web Tools embedded, you must refer to the “Software Developers” Terms and Conditions of Use”
available at http://www.usps.com/webtools/.
For more information regarding the USPS Web Tools APIs user ID policy, or for questions regarding the
distribution of documentation, please send an email to the Internet Customer Care Center (ICCC) at
https://Emailus.usps.com/.
Notice on Web Tools Account Duration: A Web Tools user ID will be deactivated if it has not been
used within the last 18 months. If your Web Tools credentials have been deactivated due to inactivity, a
new account will need to be created. Reference the Web Tools registration page
https://registration.shippingapis.com to create new Web Tools account.