Data Files
02/23/2026
AISU Contact Information (AISUADDR.TXT)
Data Files
02/23/2026
Area District Finance File Specification (AREA_DIST_LAYOUT.TXT)
Data Files
02/23/2026
Area District Finance File (AREADIST.TXT)
Data Files
02/23/2026
Area/District 3-digit and 5-digit ZIP Code Assignments (AREA_DIST_ZIP.TXT)
Data Files
02/23/2026
Move to Competitive Street Addressing (MTC SA) List

This .txt file contains the MTC SA List.

Data Files
02/20/2026
Undeliverable-as-Addressed (UAA) Mail Roll-Up 1998-2025

This spreadsheet provides a breakdown of Total UAA mail by mail class from FY1998 thru FY2025.

Data Files
02/19/2026
Z4 Info File

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

Data Files
02/19/2026
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.

 

Data Files
02/13/2026
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.

Data Files
02/09/2026
Cumulative Listing of ZIP Codes Covered by the LACS Database

This document provides a cumulative listing of ZIP Codes covered by the LACS database for LACSLink®.