Contact Lists
10/10/2024
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.

Technical Specifications
10/10/2024
Intelligent Mail Matrix Barcode (IMmb) Technical Specifications

Shipping labels on irregularly-shaped packages, softpacks, and polybags can easily become distorted or creased during automated parcel processing making reading the traditional, linear IMpb barcode challenging to scan.  USPS has developed the IMmb to help overcome these challenges and improve package visibility.  IMmb barcodes contain the same data as is in the IMpb barcode; however, they use a more robust, space-efficient robust barcode symbology for encodation.  The smaller barcode footprint allows two IMmb barcodes to be added within unused areas of existing standard shipping labels.  The result is redundancy of the barcode data giving sorters two additional chances to read the barcode. 

The US Postal Service® recommends incorporating the IMmb on all package shipping labels and it will soon become a requirement for HAZMAT shipments.

Data Files
10/10/2024
Z4 Info File

A downloadable ZIP file containing information related to the Z4 Info File

Data Files
10/10/2024
Early Warning System (EWS002C0.ZIP)

This file is the EWS production file and is updated weekly. This file contains the Early Warning System data file for the CASS™ and MASS™ certification process.

 

Announcements
10/09/2024