Tech Guides
Zone Charts Matrix Technical Guide (Effective - June 2024)

This guide details technical information about the National Zone Charts Matrix. A few topics in this guide include Defining a Zone, Matrix File General Information, and Matrix Zone Determination.

Counterfeit Postage and Fraud Prevention FAQs

To address unpaid and counterfeit postage, the USPS will validate payment documentation in real-time beginning August 1, 2024.   Packages that are unmanifested at the time of the first scan at a USPS facility will be intercepted and subject to disposal.  These packages will not reenter the mail stream and Shippers will not be reimbursed.  This document details FAQs concerning this August 1 Payment Check.  USPS wants you to be as current on the new changes as possible so we will be updating this document periodically.

Contact Lists
RDI™ Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

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