INFORMATIONAL - USPS APIs System Patching Notification – September 5 and 6, 2026

DELIVERY - Big Sur Post Office – Resumes Operations

INFORMATIONAL - Commercial System Releases – Week of September 12, 2026

Enterprise Payment System (EPS) Release Notes-September 13, 2026

Informed Visibility® Mail Tracking & Reporting (IV®-MTR) Development Tracker

This document provides a list of active IV-MTR work to be as well as items completed in the current fiscal year.

*Please note, Postal Pro is the only source for a current IV-MTR Development log as updates will be made on an ongoing basis.

Informed Visibility® Mail Tracking & Reporting (IV®-MTR) Release Notes

These release notes summarize new features and enhancements implemented in deployments to the IV-MTR application.

INFORMATIONAL - USPS APIs System Deployment – September 13, 2026

INFORMATIONAL - USPS APIs System Deployment [CR# TBD] – September 12, 2026

INFORMATIONAL - USPS APIs System Deployment – September 6, 2026

PROCESSING AND DISTRIBUTION - USPS Modernization Through Package Equipment Upgrades in September 2026

PROCESSING AND DISTRIBUTION - Update - Western Region - Beaumont, TX - Tropical Storm Edouard Impacts

Provisioning EMAS API Invoices Data in Informed Visibility® Mail Tracking & Reporting (IV®-MTR)

This guide provides instructions for receiving EMAS API Invoices data through the IV Mail Tracking & Reporting application.

National Change of Address - API

USPS PTR2 API Known Issues

CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)

RDI™ Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

This document outlines the CASS/MASS certified vendors list for RDI™ 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 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™ Certified Products Guide: Z4CHANGE Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: Z4CHANGE Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: Vendor/Service Licensees Data File Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: Vendor/Service Bureaus Licensees Cycle O - (Expires July 31, 2028)

CASS™ Certified Products Guide: DSF2® Licensees Data File Cycle O - (Expires July 31, 2028)

DSF2® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)

DPV® Licensees Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

DPV® Licensees Cycle O: Certified Products Guide - (Expires July 31, 2028)

CASS™ Software Manufacturers Data File Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

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