INFORMATIONAL – Officer Announcement – Jason DeChambeau as Acting Vice President of Processing Operations

Undeliverable-as-Addressed (UAA) Statistics by Mailing Industry Quarterly Report (Q1 FY26)

ACS Nixie stats by industry for FY26 Q1.

December 2025 Nixie Volume

This spreadsheet contains the UAA statistics for December 2025.

ZIP Codes by Area and District codes

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

Z4 Info File

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

Labeling Lists Technical Guide

The Labeling Lists data product assists mailers with presorting mail. It provides active, originating 3- and 5-digit ZIP Code™ data along with their destination locations [including city/state/ZIP Code] for labeling purposes. The product contains complete data files of each list found online via Postal Explorer® at https://pe.usps.com. Updates to the Labeling Lists are also published in the Postal Bulletin.

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 - Tracking API Provisioning Notification

Destination Entry Service Standard Directory

Combined Service Standard Directory-PRI