Data Files
05/28/2026
Population Mobility Trends 48-Month Historical (CSV) Sample File
Data Files
05/28/2026
Z4 Info File

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

Data Files
05/28/2026
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.

 

Release Notes
05/27/2026
PTR2 Release Notes_DD_05_28_26
Announcements
05/27/2026
INFORMATIONAL - Commercial System Releases (May 30 – June 5)
Release Notes
05/27/2026
PTR2 Release Notes_DD_05_26_26
Publications
05/27/2026
Labeling List Changes Effective July 1, 2026

Effective July 1, 2026, the Postal Service™ will revise Labeling List(s) L001, L007, L009, L012, L016, 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 July 1, 2026, effective date through August 31, 2026, expiration date. The changes will be published in the Postal Bulletin, Issue #22704.


 

Announcements
05/27/2026
INFORMATIONAL - July Price Change 2026 - Commercial System Releases June 28, 2026
Announcements
05/27/2026
INFORMATIONAL - Scheduled Commercial System Release - June 28, 2026
Release Notes
05/27/2026
USPS APIs Release Notes

For the latest updates, please review the USPS APIs Release Notes.