Contact Lists
12/11/2025
CASS™ Software Manufacturers Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)
Contact Lists
12/11/2025
CASS™ Software Manufacturers Cycle O - (Expires July 31, 2028)
Contact Lists
12/11/2025
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.

User Guides
12/11/2025
Provisioning Enterprise Payment (EPS) and USPS Ship (formerly Package Platform (PPC)) Data through Informed Visibility® (IV®)

This guide provides instructions for receiving Enterprise Payment System (EPS) and USPS Ship (formerly Package Platform Concept (PPC)) data through the IV Mail Tracking & Reporting (IV-MTR) application. Instructions include how to get access, create and manage a data feed, manage the address book, and manage data delegation.

Data Files
12/11/2025
Z4 Info File

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

Data Files
12/11/2025
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
12/10/2025
INFORMATIONAL- Plant-Verified Drop Shipment Updates
Announcements
12/10/2025
DELIVERY - Notification of Suspension of Mail Service - Effective December 12, 2025
Announcements
12/08/2025
INFORMATIONAL - USPS Mail Flow 101 Webinar Dec 16, 2025
Announcements
12/08/2025
INFORMATIONAL - Tracking Access Validation Notification