Data Files
04/02/2026
04/02/2026
Undeliverable-as-Addressed (UAA) Statistics by Mailing Industry Quarterly Report (Q2 FY26)
ACS Nixie stats by industry for FY26 Q2.
Data Files
04/02/2026
04/02/2026
Z4 Info File
A downloadable ZIP file containing information related to the Z4 Info File
Data Files
04/02/2026
04/02/2026
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.
Announcements
04/01/2026
04/01/2026
Announcements
04/01/2026
04/01/2026
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04/01/2026
Announcements
04/01/2026
04/01/2026
Data Files
04/01/2026
04/01/2026
Informed Visibility Mail Tracking & Reporting Machine Count
List of US Postal Service machines by site, including a description of each machine.
Data Files
04/01/2026
04/01/2026
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.
Release Notes
04/01/2026
04/01/2026
USPS APIs Release Notes
For the latest updates, please review the USPS APIs Release Notes.