Delivery - Hughesville Post Office (20637) - Resumes Operations

INFORMATIONAL - Scheduled Maintenance for November 14, 2026 – Possible Disruption with USPS Payments API

USPS Fuel Surcharge Implementation-Frequently Asked Questions

The USPS is creating a Fuel Surcharge, which will be charged on all competitively priced packages and calculated as a percentage of the base postage.  The surcharge will be updated weekly, based on the prices of diesel and jet fuel, as described on the eia.gov website.

Informed Delivery API Release Notes V1.0.3

Informed Delivery API Technical Specifications V1.0_5.1

INFORMATIONAL - USPS APIs System Release Notification - REVISED

INFORMATIONAL - Oracle PSU Patching - PPI, PASS, MANIF, GEO, and ADP

INFORMATIONAL - Commercial System Releases – October 28, 2026 and November 1, 2026

INFORMATIONAL - PostalOne! Alert – October 25, 2026

INFORMATIONAL - Informed Delivery Mailer Campaign Portal (MCP) Scheduled Outage on October 24

INFORMATIONAL - Postal One System Promotions Not Applied to Postal Wizard Statements

October 23, 2026 Program Registration 31.4.0.0 Pre-Release Notes

Mailers Technical Advisory Committee (MTAC) Membership Roster and Vacancies

Plus One Product Requirements (Technical) (Updated 10/23/26)

Plus One Updated 10/23/26

Informed Visibility® Mail Tracking & Reporting (IV®-MTR) Release Notes

These release notes summarize new features and enhancements implemented in deployments to the IV-MTR application.

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.

Intelligent Mail® for Small Business (IMsb) Fact Sheet

This fact sheet contains an overview of the IMsb Tool, its benefits, and how it works.

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.

DELIVERY - UPDATE - Akron Post Office (35441) Suspended Temporarily

INFORMATIONAL - European Union Requirements for Product Identifiers Effective November 1, 2026

Mail.xml Technical Specifications for FAST 16.0

Mail.xml Technical Specifications for FAST 14.0A

DELIVERY - Suspension of Mail Service to Argentina - Effective October 23, 2026 - November 11, 2026

PTR2 Release Notes_DD_10_24_26

PCC National Monthly Touchpoint (October)

DELIVERY - Akron Post Office (35441) Permanently Suspended

INFORMATIONAL - Executive Detail - Vice President, Strategic Sales - Sara Bambrough

INFORMATIONAL - FY2027 Peak Season Network Update Webinars

Delivery - Southern Area Alabama-Mississippi District Walnut Grove PO 35990 Temporarily Suspended

Delivery - Southern Area – Florida 1 – Valparaiso 32580 Temporary Service Suspension

October 25 2026 EPS 8.8.0.0 Release Notes