Data Files
07/11/2025
Updated List: Service Type Codes for Intelligent Mail® Package Barcode (IMpb)

This document provides the updated service type codes for  Intelligent Mail® Package Barcodes.

Tech Guides
07/10/2025
Dimensioned Layout for the 4X6 Self Adhesive Container Barcode GS1Data Matrix Format

Supports GS1 Data Matrix barcode symbology

Announcements
07/10/2025
DELIVERY - Atlantic Area – New York 1 District - College Station Post Office 10030 – Temporarily Closed
Release Notes
07/10/2025
USPS APIs Release Notes

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

Contact Lists
07/10/2025
CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)
Contact Lists
07/10/2025
RDI™ Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

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

Contact Lists
07/10/2025
CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)
Contact Lists
07/10/2025
CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)
Contact Lists
07/10/2025
CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)
Contact Lists
07/10/2025
CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)