CASS™ Software 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.

Provisioning Informed Delivery® Post-Campaign (IDPC) Data in Informed Visibility® Mail Tracking & Reporting (IV®-MTR)

This guide provides instructions for receiving Informed Delivery Post-Campaign (IDPC) detailed data through the IV Mail Tracking & Reporting (IV-MTR) application. Instructions include how to access the application, create a one-time query, create and manage a data feed, manage the address book, and manage data delegation.

Orientation Training for Informed Visibility® - Mail Tracking & Reporting (IV®-MTR)

This presentation provides an introduction to the IV-MTR application, including its purpose, user access, layout, navigation controls, and support resources.

Provisioning Mail Quality Data with Informed Visibility® Mail Tracking and Reporting

Mail Quality Data (MQD-IV) leverages the Informed Visibility^® Mail Tracking & Reporting (IV^®-MTR) application to enable mailers to receive uncapped Mail Quality Data. Detailed error data from the Mailer Scorecard is available for Full Service, Move Update, eInduction, and Seamless Acceptance.

Provisioning Enterprise Payment (EPS) and USPS Ship (formerly Package Platform (PPC)) Data through Informed Visibility® (IV®)

This guide provides instructions for receiving Enterprise Payment System (EPS) and USPS Ship (formerly Package Platform Concept (PPC)) data through the IV Mail Tracking & Reporting (IV-MTR) application. Instructions include how to get access, create and manage a data feed, manage the address book, and manage data delegation.

Informed Visibility® Mail Tracking & Reporting (IV®-MTR) User Guide

The User Guide describes the prerequisites for receiving mail tracking data through IV-MTR, the data provisioning options available, and how to use the application for tracking commercial domestic-bound barcoded letters and flats.

Informed Visibility® Mail Tracking & Reporting (IV®-MTR) Mail.XML Guide

This guide provides information about using MailXML™ to receive mail tracking data through the IV-MTR application. Through Mail.XML, mailers can receive visibility information for letter and flat containers and handling units (trays, tubs, and sacks).

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.

INFORMATIONAL - Western Region - Beaumont, TX – Tropical Storm Edouard Impacts

Mailers Technical Advisory Committee (MTAC) Membership Roster and Vacancies

USPS APIs Release Notes

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

INFORMATIONAL - UPDATE - Elevate Your Marketing Strategy with USPS 2027 Mailing Promotions Kickoff Webinar

August 2026 Nixie Volume

This spreadsheet contains the UAA statistics for August 2026.

Known Issues List 8.27.2026

MPE (Mail Processing Equipment) Service Provider Licensees

Marketing contact information for certified Mail Processing Equipment (MPE) licensees 

PCC Insider August 2026 Edition

INFORMATIONAL: Mail Spoken Here - August 2026

***Updated - New Areas*** - Area District 5-digit ZIP Codes (AREADIST_ZIP5.TXT)

City/State ZIP Code Weekly Compare

Mail Service Provider (MSP) - Full-Service Certified Mailers

A Mail Service Provider (MSP) offers a variety of solutions to prepare and present Full-Service presort mailings. For more information regarding Certified MSPs, please follow this link: https://postalpro.usps.com/full-service-cert/fact-sheet

3 Digit ZIP/AISU Office List (AISUREPT.TXT)

AIS Congressional District File (CONG_DIST.TXT)

AIS County Name Table Layout (AISCNTY.TXT)