Contact Lists
03/27/2025
03/27/2025
Contact Lists
03/27/2025
03/27/2025
CASS™/MASS™ Certified Products Guide - All Sections Data Files Cycle O - (Expires July 31, 2028)
This document contains the certified vendors list for CASS™ and MASS™ products for Cycle O.
Data Files
03/27/2025
03/27/2025
Z4 Info File
A downloadable ZIP file containing information related to the Z4 Info File
Data Files
03/27/2025
03/27/2025
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
03/26/2025
03/26/2025
Announcements
03/26/2025
03/26/2025
Announcements
03/26/2025
03/26/2025
FAQs
03/26/2025
03/26/2025
USPS Ship Frequently Asked Questions
USPS Ship Frequently Asked Questions
Publications
03/25/2025
03/25/2025