Release Notes
03/13/2026
March 22 2026 Release Notes
Data Files
03/09/2026
***Updated - New Areas*** - Area District 5-digit ZIP Codes (AREADIST_ZIP5.TXT)
Data Files
03/09/2026
City/State ZIP Code Weekly Compare
Data Files
03/09/2026
3 Digit ZIP/AISU Office List (AISUREPT.TXT)
Data Files
03/09/2026
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®.

Data Files
03/09/2026
AIS Congressional District File (CONG_DIST.TXT)
Data Files
03/09/2026
AIS County Name Table Layout (AISCNTY.TXT)
Data Files
03/09/2026
AMS County Name Table (COUNTY_NAME_TABLE.TXT)
Contact Lists
03/09/2026
AMS Address Report: AISU Mailing List (ADDRREPT.TXT)
Data Files
03/09/2026
AISU ZIP Code Record and AISU Address Record Descriptions (AISULOUT.TXT)
Data Files
03/09/2026
AISU ZIP Code File (AISUZIPS.TXT)
Data Files
03/09/2026
AISU Contact Information (AISUADDR.TXT)
Data Files
03/09/2026
Area District Finance File Specification (AREA_DIST_LAYOUT.TXT)
Data Files
03/09/2026
Area District Finance File (AREADIST.TXT)
Data Files
03/09/2026
Area/District 3-digit and 5-digit ZIP Code Assignments (AREA_DIST_ZIP.TXT)
Data Files
03/09/2026
Move to Competitive Street Addressing (MTC SA) List

This .txt file contains the MTC SA List.

Announcements
03/06/2026
INFORMATIONAL - Commercial System Releases – March 8, 2026
Release Notes
03/06/2026
PTR2 Release Notes_DD_03_07_26
Announcements
03/06/2026
INFORMATIONAL- 2026 National Postal Forum - Workshop Schedule Is Available Online
FAQs
03/06/2026
USPS PTR2 API Known Issues
Announcements
03/05/2026
INFORMATIONAL - End of USPS Web Tools Tracking 3.5.26
Contact Lists
03/05/2026
CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)
Contact Lists
03/05/2026
RDI™ Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

This document outlines the CASS/MASS certified vendors list for RDI™ Cycle O.

Contact Lists
03/05/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)
Contact Lists
03/05/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Cycle O - (Expires July 31, 2028)