Contact Lists
04/18/2024
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.

Fact Sheets
04/18/2024
Service Type Identifier (STID) Table Effective January 21, 2024

The STID (Service Type Identifier) is a three-digit numeric code used within the Intelligent Mail® barcode (IMb™) on a mailpiece that identifies the address correction or other electronic services desired. The STID Table allows you to determine which STID to use based on the mail class, address correction option, use of IV®-MTR and whether the mail contains a Full Service or Basic IMb.

Fact Sheets
04/18/2024
Locale Type Codes

Listing of available Locale Type Codes

Data Files
04/18/2024
Z4 Info File

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

Data Files
04/18/2024
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.