Data Files
10/16/2025
10/16/2025
Early Warning System (EWS002C0.ZIP)
This file is the EWS production file and is updated weekly. This file contains the Early Warning System data file for the CASS™ and MASS™ certification process.
Announcements
10/15/2025
10/15/2025
Release Notes
10/15/2025
10/15/2025
USPS APIs Release Notes
For the latest updates, please review the USPS APIs Release Notes.
Contact Lists
10/15/2025
10/15/2025
Business Acceptance Solutions & Major Mailer Support Directory
This document provides a contact list for Business Acceptance Solutions (formerly Business Mailer Support) & Major Mailer Support
Release Notes
10/14/2025
10/14/2025
Release Notes
10/14/2025
10/14/2025
Publications
10/14/2025
10/14/2025
Publications
10/14/2025
10/14/2025
Publications
10/14/2025
10/14/2025
Publications
10/14/2025
10/14/2025