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 - USPS APIs System Release - Rescheduled April 30, 2026

INFORMATIONAL - USPS Modernization Through Package Equipment Upgrades in May 2026

INFORMATIONAL - Unlock the Power of Mail Insights - The United States Postal Service’s Household Mail Survey

DELIVERY - International Service Resumption Notice – May 1, 2026

INFORMATIONAL - Executive Retirement - Randy Workman

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 FY25.

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

USPS APIs Release Notes

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

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.

Mailpiece Design Analyst (MDA) Customer Service Help Desk Brochure

An overview brochure for the MDA Customer Service Help Desk, including services, benefits, and contact information.

July 2026 Release Notes

INFORMATIONAL - USPS API System Maintenance Release Notice

INFORMATIONAL - Royal Palm, FL Processing and Distribution Center (P&DC) New Package Sorting Equipment Installation

2026 Mailing Promotions One-Pager

INFORMATIONAL - Officer Announcement – Fiona Machado - Acting Vice President, Pricing & Costing

INFORMATIONAL - Officer Announcement – Fiona Machado - Acting Vice President, Pricing & Costing

Viewing MGI Credit Balances and Postage Statements

My Products Portal customers can view incentive credit balances and postage statements
associated with their account through the portal.

PTR2 Domestic Scan Events and Descriptions

INFORMATIONAL - Package Barcode & SSF Requirements for Business Mail Entry Unit (BMEU) Parcel Mailings

Labeling List Changes Effective June 1, 2026

Effective June 1, 2026, the Postal Service™ will revise Labeling List(s) L007, L012, L014, L015, L016, L201, and L606 to reflect changes in mail processing operations. Mailers are expected to label according to these revised lists for mailings inducted on or after the June 1, 2026, effective date through July 31, 2026, expiration date. The changes will be published in the Postal Bulletin, Issue #22702.

Destination Entry Service Standard Directory

Combined Service Standard Directory-PRI

Supplemental Service Standard Directory-PRI

Supplemental Service Standard Directory-PKG