User Guides
03/12/2026
Tracking Access Control Tech Sheet

Package Tracking allows seamless integration of real-time tracking information into business systems, enabling monitoring of USPS package status from shipment to delivery.  USPS is upgrading tracking data access to enhance security and combat fraud by modernizing and securing customer access.

User Guides
03/12/2026
Premium Forwarding Service Commercial External User Guide

User Guide for the Premium Forwarding Service Commercial application. 

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03/12/2026
CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)
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03/12/2026
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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03/12/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)
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03/12/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)
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03/12/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)
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03/12/2026
CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)
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03/12/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle O - (Expires July 31, 2028)
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03/12/2026
CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle O - (Expires July 31, 2028)