Announcements
07/09/2026
INFORMATIONAL - POSTPONED – Addresses API 3.2.3 Access Postponed Until August 1, 2026
Announcements
07/09/2026
Earn a Free Mailing and Shipping Certification from the PCCAC
Program Requirements
07/09/2026
2027 Add-Ons
Program Requirements
07/09/2026
2027 Add-Ons
Program Requirements
07/09/2026
2027 Impact Messaging Promotion
Program Requirements
07/09/2026
2027 Direct Mail Discovery Promotion
Program Requirements
07/09/2026
2027 First-Class Mail Advertising Promotion
Program Requirements
07/09/2026
2027 Integrated Technology Promotion

GUIDEBOOK COMING SOON 

Program Requirements
07/09/2026
2027 Tactile, Sensory & Interactive Promotion
Announcements
07/09/2026
INFORMATIONAL - USPS Local XChange
Release Notes
07/09/2026
PTR2 Release Notes_DD_07_01_26
Fact Sheets
07/09/2026
Addresses API - Tech Sheet
Release Notes
07/09/2026
USPS APIs Release Notes

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

Contact Lists
07/09/2026
CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)
Contact Lists
07/09/2026
RDI™ Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

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

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07/09/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)
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07/09/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)
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07/09/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)
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07/09/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)
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07/09/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle O - (Expires July 31, 2028)
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07/09/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle O - (Expires July 31, 2028)
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07/09/2026
CASS™ Certified Products Guide: Z4CHANGE Data File Cycle O - (Expires July 31, 2028)
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07/09/2026
CASS™ Certified Products Guide: Z4CHANGE Cycle O - (Expires July 31, 2028)
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07/09/2026
CASS™ Certified Products Guide: Vendor/Service Licensees Data File Cycle O - (Expires July 31, 2028)
Contact Lists
07/09/2026
CASS™ Certified Products Guide: Vendor/Service Bureaus Licensees Cycle O - (Expires July 31, 2028)