INFORMATIONAL - Drop Shipment Appointments at San Antonio Annex 780MP

October 2026 - Timelimited Price Change Release

USPS APIs Release Notes

For the latest updates, please review the USPS APIs Release Notes.

PCCAC Certification Webinar: Postal Shipping Products Deep Dive with Catherine Knox

DELIVERY - Big Sur Post Office (03920) - Temporarily Closed

PTR2 Release Notes_DD_08_27_26

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 the current fiscal year.

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

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.

Informed Visibility® Mail Tracking & Reporting (IV®-MTR) Release Notes

These release notes summarize new features and enhancements implemented in deployments to the IV-MTR application.

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.

DELIVERY: WestPac Area – NV-UT District - Sierra Post Office (89506) – Resume Operations

August 27, 2026 COP Release Notes

DELIVERY: WestPac Area – CO-WY District - Hasty Post Office (81044) – Resume Operations

INFORMATIONAL: USPS Scan Event Extract Modernization Updates

PCCAC: News You Need to Know from MTAC - July 2026

PROCESSING AND DISTRIBUTION - Update - Southeast Region – Tennessee – Severe Weather Impacts

INFORMATIONAL - Commercial System Releases – August 27, 2026 – September 4, 2026

Intelligent Mail Small Business (IMsb) Tool User Guide

USPS® Approved Manufacturers of Mailing Containers for Adult Birds

A list of contact information for adult bird container manufacturers that have been certified by USPS.

DELIVERY - Sierra Post Office (89506) - Temporarily Closed

INFORMATIONAL - Elevate Your Marketing Strategy with USPS 2027 Mailing Promotions Kickoff Webinar

INFORMATIONAL - National Change of Address (NCOA+) APIs through October 19, 2026

FY 2026 PS Form 3548 Review and Verification of Circulation

***Updated - New Areas*** - Area District 5-digit ZIP Codes (AREADIST_ZIP5.TXT)

City/State ZIP Code Weekly Compare

3 Digit ZIP/AISU Office List (AISUREPT.TXT)

AIS Congressional District File (CONG_DIST.TXT)

AIS County Name Table Layout (AISCNTY.TXT)

AMS County Name Table (COUNTY_NAME_TABLE.TXT)

AMS Address Report: AISU Mailing List (ADDRREPT.TXT)

AISU ZIP Code Record and AISU Address Record Descriptions (AISULOUT.TXT)