INFORMATIONAL - USPS Modernization Through Package Equipment Upgrades in April 2026

INFORMATIONAL - Atlantic Area AIM Meeting June 2, 2026

March 2026 Nixie Volume

This spreadsheet contains the UAA statistics for March 2026.

INFORMATIONAL - Federal Register - Manifest Mailing System Retired April 1, 2026

ZIP Codes by Area and District codes

The Excel spreadsheet lists ZIP Codes with the associated Area and District Codes.  

DELIVERY - Southern Area - Puerto Rico District - Moca Post Office (00676) - Suspended

INFORMATIONAL - USPS Package Tracking Access Control Implementation (Effective Wednesday, April 1, 2026)

DELIVERY - Atlantic Area Easton Post Office (18042) - Closed Until Further Notice

INFORMATIONAL: Mail Spoken Here March 2026 Issue

INFORMATIONAL - USPS APIs System Maintenance April 15 Release

USPS APIs Terms and Conditions

ACKNOWLEDGEMENT AND ACCEPTANCE. Read this carefully before registering to use the USPS API services. By utilizing the APIs, you hereby ACCEPT ALL of the terms and conditions of this Agreement. 

USPS PTR2 API Known Issues

***Updated - New Areas*** - Area District 5-digit ZIP Codes (AREADIST_ZIP5.TXT)

City/State ZIP Code Weekly Compare

3 Digit ZIP/AISU Office List (AISUREPT.TXT)

AIS Congressional District File (CONG_DIST.TXT)

AIS County Name Table Layout (AISCNTY.TXT)

AMS County Name Table (COUNTY_NAME_TABLE.TXT)

AMS Address Report: AISU Mailing List (ADDRREPT.TXT)

AISU ZIP Code Record and AISU Address Record Descriptions (AISULOUT.TXT)

AISU ZIP Code File (AISUZIPS.TXT)

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.

March 29 2026 PostalOne! Release Notes

PTR2 Release Notes_DD_03_27_26

PTR2 Release Notes_DD_03_29_26

Labeling List Changes Effective May 1, 2026

Effective May 1, 2026, the Postal Service™ will revise Labeling List(s) L007, L012, L014, L016, L051, 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 May 1, 2026, effective date through June 30, 2026, expiration date. The changes will be published in the Postal Bulletin, Issue #22700.

INFORMATIONAL - FAST Appointment Update (03.29.2026)

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.