Applications/ Forms
07/17/2026
LACSLink® End User License Agreement

This document contains the End User License Agreement for LACSLink®.

Announcements
07/16/2026
DELIVERY - Trail Post Office - Temporarily Closed
Announcements
07/16/2026
DELIVERY - Weston Post Office - Temporarily Closed
Announcements
07/16/2026
INFORMATIONAL - Expansion of Daily Webinar Series through September 4, 2026
Release Notes
07/16/2026
July 17, 2026 Customer Onboarding Portal R2.5.4.0
Announcements
07/16/2026
DELIVERY - Eureka Post Office – Resume Operations
Release Notes
07/16/2026
USPS APIs Release Notes

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

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07/16/2026
CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)
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07/16/2026
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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07/16/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: Z4CHANGE Data File Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: Z4CHANGE Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: Vendor/Service Licensees Data File Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: Vendor/Service Bureaus Licensees Cycle O - (Expires July 31, 2028)
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07/16/2026
CASS™ Certified Products Guide: DSF2® Licensees Data File Cycle O - (Expires July 31, 2028)
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07/16/2026
DSF2® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)
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07/16/2026
DPV® Licensees Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)
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07/16/2026
DPV® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)
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07/16/2026
CASS™ Software Manufacturers Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)
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07/16/2026
CASS™ Software Manufacturers Cycle O - (Expires July 31, 2028)