Contact Lists
06/26/2025
CASS™ Certified Products Guide: Vendor/Service Bureaus Licensees Cycle O - (Expires July 31, 2028)
Contact Lists
06/26/2025
CASS™ Certified Products Guide: DSF2® Licensees Data File Cycle O - (Expires July 31, 2028)
Contact Lists
06/26/2025
DSF2® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)
Contact Lists
06/26/2025
DPV® Licensees Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)
Contact Lists
06/26/2025
DPV® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)
Contact Lists
06/26/2025
CASS™ Software Manufacturers Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)
Contact Lists
06/26/2025
CASS™ Software Manufacturers Cycle O - (Expires July 31, 2028)
Contact Lists
06/26/2025
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.

User Guides
06/26/2025
Mailing and Shipping Solutions Center (MSSC) Topics

List of topics the MSSC can assist with. To reach the MSSC, email us at MSSC@usps.gov or call 1-877-672-0007 from 7:00AM – 7:00PM CT.

Fact Sheets
06/26/2025
About Mailers' Technical Advisory Committee (MTAC) User Group 4

This document provides a brief description of MTAC User Group 4 for mail visibility and provides a contact for requesting to join the group.