Announcements
05/15/2026
Post Office/ZIP Code Entries for Postal Bulletin 5/28/2026

This spreadsheet provides details on the Post Office/ZIP Code entry changes for Postal Bulletin issue 5/28/2026.

Announcements
05/14/2026
INFORMATIONAL - Package Tracking API Provisioning Reminder
Announcements
05/14/2026
INFORMATIONAL - Reminder - USPS Enhanced Addresses API – Coming July 2026
Contact Lists
05/14/2026
CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)
Contact Lists
05/14/2026
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
05/14/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)
Contact Lists
05/14/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)
Contact Lists
05/14/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)
Contact Lists
05/14/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)
Contact Lists
05/14/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle O - (Expires July 31, 2028)