Fact Sheets
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.

Applications/ Forms
PS Form 3553: CASS™ Summary Report

This form is the CASS™ Summary Report.

Fact Sheets
Unique ZIP® Code Flowchart

This flowchart describes the logic flow for Unique ZIP codes.

Contact Lists
07/18/2024
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.

Data Files
07/18/2024
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.

Contact Lists
07/18/2024
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.

Data Files
07/18/2024
Z4 Info File

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

Tech Guides
03/19/2024
MASS™ Technical Guide for Cycle O

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

Tech Guides
03/19/2024
MASS™ Technical Guide for Cycle O

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

Contact Lists
04/20/2023
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.

Contact Lists
04/20/2023
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.

Contact Lists
04/20/2023
RDI™ Cycle N: Certified Products Guide (D) - (Expires July 31, 2023)

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

Contact Lists
04/20/2023
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.

Contact Lists
04/20/2023
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.

Contact Lists
04/20/2023
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.

Contact Lists
04/20/2023
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.

Contact Lists
04/20/2023
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.

Applications/ Forms
03/20/2023
Z4CHANGE Order Form

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

Applications/ Forms
03/20/2023
CASS™ Order Form

This docoument contains the order form for CASS™.

Applications/ Forms
03/17/2023
MASS™ Order Form

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

Applications/ Forms
03/17/2023
MASS™ Order Form

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

Applications/ Forms
12/20/2022
Terms and Conditions document for MASS™ Manufacturers

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

Applications/ Forms
12/20/2022
Terms and Conditions document for MASS™ Manufacturers

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

Applications/ Forms
12/20/2022
Terms and Conditions document for MASS™ End-Users

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

Applications/ Forms
12/20/2022
Terms and Conditions document for MASS™ End-Users

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

Applications/ Forms
12/01/2022
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.

Tech Guides
02/21/2018
MASS™ Technical Guide for Cycle N

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

Tech Guides
02/21/2018
MASS™ Technical Guide for Cycle N

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

Tech Guides
02/16/2018
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.

Applications/ Forms
09/21/2017
Enhanced Line of Travel (eLOT) Order Form

This document provides an order form for eLOT.

Announcements
07/26/2017
Presentations
10/10/2014
MASS™ Electronic Testing

This presentation provides information on electronic testing for MASS™.

Presentations
10/10/2014
MASS™ Electronic Testing

This presentation provides information on electronic testing for MASS™.

Announcements
05/07/2013
CASS™ and MASS™ Cycle O Deferment Letter

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

Data Files
12/03/2010
CASS™ Cycle N Stage I File

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

Data Files
07/13/2010
Delivery Type Cycle N Static Data

This text file provides delivery type Cycle N static data

Data Files
07/08/2010
R9 RDI™ Cycle N Static Data

This zip file contains RDI 9-digit static data.

Data Files
07/08/2010
R11 RDI™ Cycle N Static Data

This zip file contains RDI 11-digit static data.

Presentations
03/30/2010
CASS™ Cycle N Partnership in Tomorrow Presentation

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

Fact Sheets
03/30/2010
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.

Announcements
10/29/2009
CASS™ and MASS™ Cycle N Deferment Letter

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

Tech Guides
05/01/2006
Z4 Info File Layout

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

Tech Guides
04/28/2005
Tech Guides
04/28/2005