PTR2 Release Notes_DD_05_21_26

PTR Tracking API Specifications and Integration

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.

Z4 Info File

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

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 - Updated 5-20-2026 - 2026 Labeling List and Mail Direction File (MDF) Timeline

DELIVERY - Diplomatic Post Office (DPO) May 20, 2026

INFORMATIONAL - USPS APIs System Release May 21, 2026

Mail.xml Technical Specifications R64.0.0.0

Mail.dat Technical Specifications R64.0.0.0

July 2026 Release Overview

Note: For the latest technical specifications, please see the July 2026 Price Change Release Notes as they are published. Mail.dat and Mail.XML updates required for this release. 

PCC National Monthly Touchpoint (May)

PCC National Monthly Touchpoint Recording (May)

Passcode: S+?yXQe3

INFORMATIONAL - Mailer Scorecard - Temporarily Unavailable

INFORMATIONAL - Updated - 2026 Labeling List and Mail Direction File (MDF) Timeline

PTR2 Release Notes_DD_05_19_26

Informed Visibility® Mail Tracking & Reporting (IV®-MTR) Development Tracker

This document provides a list of active IV-MTR work to be as well as items completed in FY25.

*Please note, Postal Pro is the only source for a current IV-MTR Development log as updates will be made on an ongoing basis.

May 31 2026 EPS/eBill R8.4.0.0 Release Notes

IMpb (Intelligent Mail® Package Barcode & IMmb (Intelligent Mail® Matrix Barcode) Verification Fact Sheet

DELIVERY - International Service Resumption Notice – Effective May 19, 2026

INFORMATIONAL - USPS APIs System Release - Rescheduled May 28, 2026

INFORMATIONAL - USPS APIs System Release May 26, 2026

***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)