May 17 2026 PostalOne! R63.2.2.0 Release Notes

May 17 2026 USPS Ship R27.0.0.0 Release Notes

***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)

AISU ZIP Code File (AISUZIPS.TXT)

AISU Contact Information (AISUADDR.TXT)

Area District Finance File Specification (AREA_DIST_LAYOUT.TXT)

Area District Finance File (AREADIST.TXT)

Area/District 3-digit and 5-digit ZIP Code Assignments (AREA_DIST_ZIP.TXT)

Move to Competitive Street Addressing (MTC SA) List

This .txt file contains the MTC SA List.

INFORMATIONAL - Executive Retirement - Himesh Patel

INFORMATIONAL - Commercial System Releases – May 10, 2026

INFORMATIONAL - Executive Retirement - Robert H. Raines Jr

April 2026 Nixie Volume

This spreadsheet contains the UAA statistics for April 2026.

ZIP Codes by Area and District codes

The Excel spreadsheet lists ZIP Codes with the associated Area and District Codes.  

INFORMATIONAL - Officer Appointments - Chief Solutions & Strategy Officer and Vice President of Network Solutions & Performance Excellence

DELIVERY - Falkland Post Office (27827) - Temporarily Closed

INFORMATIONAL: Mail Spoken Here - April Issue

PCC Insider April 2026 Edition

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.

USPS Ship Data Dictionary

Detailed information on the USPS Ship (Formerly Package Platform) data elements available through the Informed Visibility Mail Tracking & Reporting (IV-MTR) application. Please note that items in bold text were updated or added recently.

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 APIs System Release - Rescheduled April 30, 2026

INFORMATIONAL - USPS Modernization Through Package Equipment Upgrades in May 2026

INFORMATIONAL - Unlock the Power of Mail Insights - The United States Postal Service’s Household Mail Survey