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 Notification – August 31, 2026

DELIVERY - La Villa Post Office (78562) - Temporarily Suspended

DELIVERY: WestPac Area - NV-UT District - Nixon Post Office (89424) - Office Temporarily Closed

Request to Lead or Participate - MTAC User Group and Work Group

USPS PTR2 API Known Issues

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.

USPS APIs Release Notes

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

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.

Mini Cafe Part Two - Informed Delivery for PCCs

Mail Service Provider (MSP) - Full-Service Certified Mailers

A Mail Service Provider (MSP) offers a variety of solutions to prepare and present Full-Service presort mailings. For more information regarding Certified MSPs, please follow this link: https://postalpro.usps.com/full-service-cert/fact-sheet

Modernization of Address Processing with APIs - Q & A

USPS Addresses API - Completing PS Form 3553

INFORMATIONAL - Commercial System Releases – Week of August 15, 2026

INFORMATIONAL - PostalOne! Release – August 16, 2026

August 9, 2026 Program Registration R31.1.0.0 Release Notes

August 9, 2026 eSAS R47.2.0.0 Release Notes

August 16, 2026 PostalOne! and USPS Ship Release

***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)

Cumulative Listing of ZIP Codes Covered by the LACS Database

This document provides a cumulative listing of ZIP Codes covered by the LACS database for LACS^Link®.

AIS Congressional District File (CONG_DIST.TXT)

AIS County Name Table Layout (AISCNTY.TXT)