Announcements
11/02/2026
INFORMATIONAL - USPS APIs System Release Notification November 12
Publications
10/30/2026
PCCAC Marketing and Communications October 2026 Newsletter
Announcements
10/30/2026
INFORMATIONAL - Mail Spoken Here - October Issue
Announcements
10/30/2026
INFORMATIONAL - Executive Retirement - Peter R. Pastre
Announcements
10/30/2026
INFORMATIONAL - Officer Appointment - Vice President, Regulatory Pricing and Costing – Fiona Machado
Publications
10/30/2026
PCC Insider October 2026 Special PCC Week Edition
Announcements
10/30/2026
INFORMATIONAL - Commercial System Releases – November 3, November 10, and November 12, 2026
Announcements
10/30/2026
INFORMATIONAL - Legacy Tracking API Retirement + Scan Event Extract Modernization
Release Notes
10/30/2026
November 12 2026 COP 2.5.9 Release Notes

Coming soon

Announcements
10/29/2026
NPF Call for Presentations Closing 10/30/2026
Announcements
10/29/2026
INFORMATIONAL - PostalOne! System – Issues with Promotion Removal and Auto-Finalized Postal Wizard Statements
Announcements
10/29/2026
INFORMATIONAL - NPF 2027 Call for Presentations is closing on Friday, October 30th
Program Requirements
10/29/2026
2026 Promotions FAQ
Release Notes
10/29/2026
USPS APIs Release Notes

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

Contact Lists
10/29/2026
CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
RDI™ Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

This document outlines the CASS/MASS certified vendors list for RDI™ Cycle O.

Contact Lists
10/29/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: Z4CHANGE Data File Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: Z4CHANGE Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: Vendor/Service Licensees Data File Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: Vendor/Service Bureaus Licensees Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Certified Products Guide: DSF2® Licensees Data File Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
DSF2® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)
Contact Lists
10/29/2026
DPV® Licensees Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)
Contact Lists
10/29/2026
DPV® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Software Manufacturers Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)
Contact Lists
10/29/2026
CASS™ Software Manufacturers Cycle O - (Expires July 31, 2028)
Contact Lists
10/29/2026
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.

Data Files
10/29/2026
Z4 Info File

A downloadable ZIP file containing information related to the Z4 Info File

Data Files
10/29/2026
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
10/28/2026
INFORMATIONAL - USPS APIs System Deployment November 14
Announcements
10/28/2026
INFORMATIONAL - USPS APIs System Deployment November 8
Announcements
10/28/2026
INFORMATIONAL - USPS APIs System Deployment November 1
Announcements
10/28/2026
INFORMATIONAL - USPS APIs System Deployment - November 1
Announcements
10/28/2026
INFORMATIONAL - USPS APIs System Release Notification November 5
Announcements
10/28/2026
INFORMATIONAL -Informed Visibility USPS Ship Subscription Delays During Daylight Savings Time
Announcements
10/28/2026
DELIVERY - International Resumption of Mail Service Argentina - Effective October 30, 2026