Announcements
09/04/2026
INFORMATIONAL - Commercial System Releases – Week of September 12, 2026
Release Notes
09/04/2026
Enterprise Payment System (EPS) Release Notes-September 13, 2026

Coming soon

Announcements
09/03/2026
INFORMATIONAL - USPS APIs System Deployment – September 13, 2026
Announcements
09/03/2026
INFORMATIONAL - USPS APIs System Deployment [CR# TBD] – September 12, 2026
Announcements
09/03/2026
INFORMATIONAL - USPS APIs System Deployment – September 6, 2026
Announcements
09/03/2026
PROCESSING AND DISTRIBUTION - USPS Modernization Through Package Equipment Upgrades in September 2026
Announcements
09/03/2026
PROCESSING AND DISTRIBUTION - Update - Western Region - Beaumont, TX - Tropical Storm Edouard Impacts
User Guides
09/03/2026
Provisioning EMAS API Invoices Data in Informed Visibility® Mail Tracking & Reporting (IV®-MTR)

This guide provides instructions for receiving EMAS API Invoices data through the IV Mail Tracking & Reporting application.

Technical Specifications
09/03/2026
National Change of Address - API
FAQs
09/03/2026
USPS PTR2 API Known Issues
Contact Lists
09/03/2026
CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
RDI™ Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

This document outlines the CASS/MASS certified vendors list for RDI™ Cycle O.

Contact Lists
09/03/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: Z4CHANGE Data File Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: Z4CHANGE Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: Vendor/Service Licensees Data File Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: Vendor/Service Bureaus Licensees Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
CASS™ Certified Products Guide: DSF2® Licensees Data File Cycle O - (Expires July 31, 2028)
Contact Lists
09/03/2026
DSF2® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)
Contact Lists
09/03/2026
DPV® Licensees Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)