INFORMATIONAL -Upcoming USPS.com Maintenance CANCELLED

DELIVERY Resumption of Mail Service to Lebanon- Effective April 3, 2026

PCC Events (April 2026)

Undeliverable-as-Addressed (UAA) Statistics by Mailing Industry Quarterly Report (Q2 FY26)

ACS Nixie stats by industry for FY26 Q2.

Destination Entry Service Standard Directory

Combined Service Standard Directory-PRI

Supplemental Service Standard Directory-PRI

Supplemental Service Standard Directory-PKG

Supplemental Service Standard Directory-PFC

Supplemental Service Standard Directory-PER

Supplemental Service Standard Directory-MKT

Supplemental Service Standard Directory-GAL

Supplemental Service Standard Directory-GAH

Supplemental Service Standard Directory-FCM

Combined Service Standard Directory-GAL

Combined Service Standard Directory-PKG

Combined Service Standard Directory-PFC

Combined Service Standard Directory-PER

Combined Service Standard Directory-MKT

Combined Service Standard Directory-GAH

Combined Service Standard Directory-FCM

3D Base Service Standard Directory

CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)

RDI™ Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

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

CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: Z4CHANGE Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: Z4CHANGE Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: Vendor/Service Licensees Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: Vendor/Service Bureaus Licensees Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: DSF2® Licensees Data File Cycle O - (Expires July 31, 2028)

DSF2® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)

DPV® Licensees Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

DPV® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)

CASS™ Software Manufacturers Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

CASS™ Software Manufacturers Cycle O - (Expires July 31, 2028)

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.

Publication 199: Intelligent Mail Package Barcode (IMpb) Implementation Guide for Confirmation Services and Electronic Payment Systems

Z4 Info File

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

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.

INFORMATIONAL - USPS Modernization Through Package Equipment Upgrades in April 2026

INFORMATIONAL - Atlantic Area AIM Meeting June 2, 2026

March 2026 Nixie Volume

This spreadsheet contains the UAA statistics for March 2026.

INFORMATIONAL - Federal Register - Manifest Mailing System Retired April 1, 2026

Informed Visibility Mail Tracking & Reporting Machine Count

List of US Postal Service machines by site, including a description of each machine.

Informed Visibility® Mail Tracking & Reporting (IV®-MTR) Development Tracker

This document provides a list of active IV-MTR work to be as well as items completed in FY25.

*Please note, Postal Pro is the only source for a current IV-MTR Development log as updates will be made on an ongoing basis.