Unique ZIP® Code Flowchart

This flowchart describes the logic flow for Unique ZIP codes.

PS Form 3553: CASS™ Summary Report

This form is the CASS™ Summary Report.

Unique ZIP® Code Matrix

The Unique ZIP Code Matrix displays Carrier Route ID, Record Type, and Delivery Point assignment rules within unique ZIP codes only.

CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)

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.

CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle O - (Expires July 31, 2028)

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.

CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle O - (Expires July 31, 2028)

Z4 Info File

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

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.

CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle O - (Expires July 31, 2028)

MASS™ Technical Guide for Cycle O

This document provides a technical guide for MASS™ Cycle O. MASS™ is an extension of the CASS™ system.

MASS™ Technical Guide for Cycle O

This document provides a technical guide for MASS™ Cycle O. MASS™ is an extension of the CASS™ system.

CASS™ and MASS™ Certified Products Guide Cycle: 2023-2028

CASS™ and MASS™ Certified Products Guide Cycle: 2023-2028

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle N - (Expires July 31, 2023)

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle N - (Expires July 31, 2023)

CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle N - (Expires July 31, 2023)

CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle N - (Expires July 31, 2023)

CASS™ Certified Products Guide: M L O C R Service Bureaus Cycle N - (Expires July 31, 2023)

CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle N - (Expires July 31, 2023)

CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle N - (Expires July 31, 2023)

DSF2® Licensees Cycle N: Certified Products Guide - (Expires July 31, 2023)

This document contains the CASS™/MASS™ certified vendors list for DSF2® Licensees for Cycle N.

DPV® Licensees Cycle N: Certified Products Guide - (Expires July 31, 2023)

This document contains the CASS™/MASS™ certified vendors list for DPV® Licensees Cycle N.

CASS™/MASS™ Certified Products Guide - All Sections Data Files Cycle N - (Expires July 31, 2023)

This document contains the certified vendors list for CASS™ and MASS™ products for Cycle N.

CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle N - (Expires July 31, 2023)

CASS™ Software Manufacturers Cycle N - (Expires July 31, 2023)

This document contains the CASS™/MASS™ certified vendors list for CASS software manufacturers for Cycle N.

CASS™ Certified Products Guide: Vendor/Service Bureaus Licensees Cycle N - (Expires July 31, 2023)

RDI™ Cycle N: Certified Products Guide (D) - (Expires July 31, 2023)

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

CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle N - (Expires July 31, 2023)

CASS™ Certified Products Guide: M L O C R Service Bureaus Data File Cycle N - (Expires July 31, 2023)

CASS™ Software Manufacturers Data File Cycle N: Certified Products Guide (D) - (Expires July 31, 2023)

This document contains the CASS™/MASS™ certified vendors list for CASS™ software manufacturers for Cycle N.

CASS™ Certified Products Guide: Vendor/Service Licensees Data File Cycle N - (Expires July 31, 2023)

DPV® Licensees Data File Cycle N: Certified Products Guide (D) - (Expires July 31, 2023)

This document contains the CASS™/MASS™ certified vendors list for DPV® Licensees Data File for Cycle N.

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Cycle N - (Expires July 31, 2023)

CASS™ Certified Products Guide: M L O C R Hardware Manufacturers Data File Cycle N - (Expires July 31, 2023)

CASS™/MASS™ Certified Products Guide - All Sections Data Files Cycle N - (Expires July 31, 2023)

This document contains the certified vendors list for CASS™ and MASS™ products for Cycle N.

Z4CHANGE Order Form

This order form is used to subscribe to the Z4CHANGE product. 

CASS™ Order Form

This document contains the order form for CASS™.

MASS™ Order Form

This is an order form to request a test deck for MASS™ certification/recertification.

MASS™ Order Form

This is an order form to request a test deck for MASS™ certification/recertification.

Terms and Conditions document for MASS™ End-Users

This document outlines the terms and conditions form for MASS™ certification for end users.

Terms and Conditions document for MASS™ End-Users

This document outlines the terms and conditions form for MASS™ certification for end users.

Terms and Conditions document for MASS™ Manufacturers

This document outlines the terms and conditions form for MASS™ certification.

Terms and Conditions document for MASS™ Manufacturers

This document outlines the terms and conditions form for MASS™ certification.

Electronic Product Fulfillment (EPF) Web Access Request Form

This form is used to create a Web-based account with the Addressing and Geospatial Technology (AGT) office which will be utilized to retrieve/download files from the Electronic Product Fulfillment (EPF) website.

Guidelines for Printing LACSLink® Information

Guidelines for Printing LACSLink® Information

MASS™ Technical Guide for Cycle N

This document provides a technical guide for MASS™ Cycle N. MASS™ is an extension of the CASS™ system.

MASS™ Technical Guide for Cycle N

This document provides a technical guide for MASS™ Cycle N. MASS™ is an extension of the CASS™ system.

CASS™ Technical Guide for Cycle N

This document provides a technical guide for the CASS™ product. The CASS™ certification process is designed in cooperation with the mailing industry to improve the accuracy of addresses for mail qualifying for postal discounts.

Enhanced Line of Travel (eLOT) Order Form

This document provides an order form for eLOT.

CASS™ MASS™ Test Files on EPF

MASS™ Electronic Testing

This presentation provides information on electronic testing for MASS™.

MASS™ Electronic Testing

This presentation provides information on electronic testing for MASS™.

CASS™ and MASS™ Cycle O Deferment Letter

This letter announces the deferment of CASS™/MASS™ Cycle O implementation.

CASS™ Cycle N Stage I File

This zip file is for categories only processed with 2009-2011 Cycle N static data.

Delivery Type Cycle N Static Data

This text file provides delivery type Cycle N static data

R9 RDI™ Cycle N Static Data

This zip file contains RDI 9-digit static data.

R11 RDI™ Cycle N Static Data

This zip file contains RDI 11-digit static data.

CASS™ Cycle N Partnership in Tomorrow Presentation

This Partnership in Tomorrow presentation reviews CASS/MASS Cycle M and N requirements.

CASS™ Cycle N Partnership in Tomorrow Minutes

The Partnership in Tomorrow Meeting was hosted by the National Customer Support Center in Memphis, TN with attendees and webinar participants from various industry representatives.

CASS™ and MASS™ Cycle N Deferment Letter

The implementation date for CASS/MASS Cycle N is being deferred to August 1, 2011.

Z4 Info File Layout

This data file presents a table of codes for primary and secondary numbers to describe Z4Info files.

CASS™ and MASS™ Guidelines