Data Files
07/31/2025
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
07/30/2025
DELIVERY - Atlantic Area – New York 3 District - Clayton Post Office (13624)- Office Temporarily Closed
Announcements
07/30/2025
DELIVERY - WestPac Area – California 1 District Forks of Salmon Post Office (96031) – Resumes Operations
Announcements
07/30/2025
DELIVERY - WestPac Area - Washington District Lyle Post Office (98635) – Resumes Operations
Publications
07/30/2025
PCCAC Communications and Marketing – Newsletter
Release Notes
07/30/2025
July 30 2025 Release Notes
User Guides
07/30/2025
Domestic Merchant Returns API: User Guide

This user guide provides examples of XML transactions to the USPS Merchant Returns web service and guidance for installation.

Announcements
07/29/2025
DELIVERY - UPDATE - North Rose Post Office (14516) – NY3 District Temporarily Closed
Release Notes
07/29/2025
USPS APIs Release Notes

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

Announcements
07/28/2025
DELIVERY - Southern Area - Texas 1 District - Corrigan Post Office (75939) - Temporarily Suspended