Contact Lists
11/12/2026
CASS™ Software Manufacturers Cycle O - (Expires July 31, 2028)
Contact Lists
11/12/2026
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.

Applications/ Forms
11/12/2026
Informed Visibility® Mail Tracking & Reporting (IV®-MTR) Piece-Level One-Time Query Request

This form is to help users prepare to submit a one-time query for piece-level data, either on their own through the IV-MTR web application or assistance from the IV Solutions Center.

Data Files
11/12/2026
Informed Visibility® Mail Tracking & Reporting (IV®-MTR) Operation Codes List

This spreadsheet provides a list of operation codes (opcodes), also known as Scan Event Codes, for the IV-MTR application.

Data Files
11/12/2026
Z4 Info File

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

Data Files
11/12/2026
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
11/10/2026
New National Industry AIM Co-Chair – Alexis Nicoletta
Announcements
11/10/2026
INFORMATIONAL - UPDATE - Discontinuance of USPS Tracking Labels (888, 889, 891, 892)
Announcements
11/10/2026
INFORMATIONAL - New National Industry AIM Co-Chair - Alexis Nicoletta
Announcements
11/10/2026
INFORMATIONAL - Zoom Technical Difficulty - FY2027 Peak Season Network Update Webinars Begin Nov 12