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
02/02/2023
CASS™/MASS™ Certified Products Guide - All Sections Data Files Current Cycle

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

Data Files
02/02/2023
Z4 Info File

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

Contact Lists
02/02/2023
RDI™ Current Cycle: Certified Products Guide (D)

This document outlines the CASS/MASS certified vendors list for RDI™ Current Cycle (D).

Contact Lists
02/02/2023
CASS™ Software Manufacturers Data File Current Cycle: Certified Products Guide (D)

This document contains the CASS™/MASS™ certified vendors list for CASS™ software manufacturers current cycle (D).

Contact Lists
02/02/2023
CASS™/MASS™ Certified Products Guide - All Sections Data Files Current Cycle

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

Data Files
02/02/2023
Early Warning System (EWS002C0.ZIP)

This document contains the Early Warning System data file for the CASS™ and MASS™ certification process.

Contact Lists
02/02/2023
DPV® Licensees Current Cycle: Certified Products Guide

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

Contact Lists
02/02/2023
DPV® Licensees Data File Current Cycle: Certified Products Guide (D)

This document contains the CASS™/MASS™ certified vendors list for DPV® Licensees Data File Current Cycle (D).

Contact Lists
02/02/2023
DSF2® Licensees Current Cycle: Certified Products Guide

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

Contact Lists
02/02/2023
CASS™ Software Manufacturers Current Cycle

This document contains the CASS™/MASS™ certified vendors list for CASS software manufacturers current cycle.

Applications/ Forms
01/27/2023
MASS™ Order Form

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

Applications/ Forms
01/27/2023
Z4Change Order Form

This order form is used to subscribe to the Z4Change product. 

Applications/ Forms
01/27/2023
CASS™ Order Form

This docoument contains the order form for CASS™.

Applications/ Forms
01/27/2023
RDI™ Order form

This order form allows customers to order the RDI™ product.

Applications/ Forms
01/27/2023
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™ 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™ 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
12/01/2022
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 documet 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 documet 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
Publications
03/07/2016
Domestic Mail Manual (DMM®) 509: Address Information System Products

Address Management provides services that enable customers to manage thequality of their mailing lists while maximizing the Postal Service's ability to efficiently deliver mail.

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.

Announcements
07/11/2012
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.

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.

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

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

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.

Fact Sheets
04/22/2008
1997-1998 CASS™ Update Secondary Delivery Point

This document discusses delivery point codes for highrise secondary addresses.

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
Presentations
08/25/1999
2000-2001 CASS™ Meeting Minutes & Presentations

This zip file contains the 2000-2001 CASS™ Partnership in Tomorrow presentation and meeting minutes.

Presentations
12/14/1998
1999-2000 CASS™ Meeting Minutes & Presentations

This zip file contains CASS™ and MASS™ presentations and meeting minutes from the Partnership in Tomorrow meeting from December 14, 1998, as well as the CASS™ Summary Report Form.