AISU Contact Information (AISUADDR.TXT)

Area District Finance File Specification (AREA_DIST_LAYOUT.TXT)

Area District Finance File (AREADIST.TXT)

Area/District 3-digit and 5-digit ZIP Code Assignments (AREA_DIST_ZIP.TXT)

Move to Competitive Street Addressing (MTC SA) List

This .txt file contains the MTC SA List.

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.

Labeling List Changes Effective September 1, 2026

Effective September 1, 2026, the Postal Service™ will revise Labeling List(s) L007, L008, L012, L016, L201, L606, and L607 to reflect changes in mail processing operations. Mailers are expected to label according to these revised lists for mailings inducted on or after the September 1, 2026, effective date through October 31, 2026, expiration date. The changes will be published in the Postal Bulletin, Issue #22708.

 

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 Ship Data Dictionary

Detailed information on the USPS Ship (Formerly Package Platform) data elements available through the Informed Visibility Mail Tracking & Reporting (IV-MTR) application. Please note that items in bold text were updated or added recently.