Contact Lists
02/19/2026
DPV® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)
Contact Lists
02/19/2026
CASS™ Software Manufacturers Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)
Contact Lists
02/19/2026
CASS™ Software Manufacturers Cycle O - (Expires July 31, 2028)
Contact Lists
02/19/2026
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
02/19/2026
Z4 Info File

A downloadable ZIP file containing information related to the Z4 Info File

Data Files
02/19/2026
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
02/18/2026
INFORMATIONAL - Pub 401 and Manifest Mailing System (MMS) Retirement
Release Notes
02/18/2026
February 25 2026 Release Notes
Announcements
02/17/2026
INFORMATIONAL: Commercial System Releases - February 22, 2026
Announcements
02/17/2026
INFORMATIONAL: USPS APIs System Maintenance - February 25, 2026