01/09/2026
01/06/2026
01/06/2026
USPS Ship Tech Sheet
USPS Ship is a modernized platform enabling commercial package payment, verification, and end-to-end visibility for a wide array of domestic and international products.
01/02/2026
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.
11/26/2025
PostalOne! Release 63.0.0.0 Mail.XML TEM WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ TEM Release 63.0.0.0
11/26/2025
11/26/2025
PostalOne! Release 63.0.0.0 Mail.XML PROD WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ PROD Release 63.0.0.0
11/26/2025
PostalOne! Release 63.0.0.0 Mail.XML CAT WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ CAT Release 63.0.0.0
10/06/2025
10/06/2025
Intelligent Mail Container Barcode Technical Specifications
Technical specifications for printing the USPS Intelligent Mail® Container barcode (IM™ Container barcode). The Intelligent Mail Container barcode is used on mailer-generated pallet labels to uniquely identify pallets and similar containers (i.e. All Purpose Containers, hampers, pallet boxes, etc.) in addition to identifying the mail owner.
08/08/2025
07/24/2025
07/07/2025
Intelligent Mail Tray Label Technical Fact Sheet
This document provides fact sheet providing technical specifications on the acquisition, implementation, and benefits of the Intelligent Mail Tray Label.
06/18/2025
PostalOne! Release 62.0.0.0 Mail.XML CAT WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ CAT Release 62.0.0.0
06/18/2025
06/18/2025
PostalOne! Release 62.0.0.0 Mail.XML TEM WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ TEM Release 62.0.0.0
06/18/2025
PostalOne! Release 62.0.0.0 Mail.XML PROD WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ PROD Release 62.0.0.0
06/13/2025
Informed Delivery Mail.XML Mailer Guide
This is a guide for submitting campaigns to PostalOne! via Mail.XML electronic documentation (eDoc).
06/13/2025
Informed Delivery Mail.dat Mailer Guide
This is a mailer guide for creating campaigns via PostalOne! through Mail.dat eDoc submission.
05/06/2025
eVS to USPS Ship Migration Tech Sheet
The Postal Service is retiring the electronic verification system (eVS). eVS customers must migrate to USPS Ship or USPS APIs by February 2025. This includes customers using Premium Forwarding Services Commercial (PFSC) and Click N Ship BusinessPro (CNBPro). This document outlines the differences between the two platforms and steps to migrate from eVS to USPS Ship.
05/06/2025
03/07/2025
Secure Destruction Technical Guide
A technical reference for implementing the Secure Destruction process
02/21/2025
ACS™ Electronic Product Fulfillment (EPF) Fulfillment File Access
Learn the different methods of accessing your ACS™ files from EPF.
01/23/2025
12/12/2024
PostalOne! Release 61.0.0.0 Mail.XML PROD WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ PROD Release 61.0.0.0
12/12/2024
PostalOne! Release 61.0.0.0 Mail.XML TEM WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ TEM Release 61.0.0.0
12/12/2024
12/12/2024
12/03/2024
11/15/2024
10/16/2024
MASS™ Technical Guide for Cycle O
This document provides a technical guide for MASS™ Cycle O. MASS™ is an extension of the CASS™ system.
07/18/2024
Business Customer Gateway: Overview and Tour
This presentation provides an overview of the Business Customer Gateway and a tour for new users.
07/17/2024
06/04/2024
API Tech Sheet
The USPS API Platform provides a dynamic, one-stop-shop of shipping capabilities to expand business reach
and increase efficiency. The USPS suite of APIs enables integrators to standardize an address, price a
package, create a label, find a USPS acceptance facility, schedule a carrier pick-up, and track a package from
entry to delivery. The USPS API platform also offers webhooks for near-real-time push notifications for tracking
events.
06/01/2024
Zone Charts Matrix Technical Guide (Effective - June 2024)
This guide details technical information about the National Zone Charts Matrix. A few topics in this guide include Defining a Zone, Matrix File General Information, and Matrix Zone Determination.
05/10/2024
PostalOne! Release 60.0.0.0 Mail.XML PROD WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ PROD Release 60.0.0.0
05/10/2024
PostalOne! Release 60.0.0.0 Mail.XML PrePROD WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ PrePROD Release 60.0.0.0
05/10/2024
PostalOne! Release 60.0.0.0 Mail.XML TEM WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ TEM Release 60.0.0.0
05/10/2024
05/08/2024
ACS™ Electronic Product Fulfillment (EPF) Download Manager Technical Guide
Documentation for the Client Side ACS™ EPF Download Manager software package.
03/19/2024
CASS™ Technical Guide for Cycle O
This document provides a technical guide for the CASS™ product. The CASS certification process is designed in cooperation with the mailing industry to improve the accuracy and deliverability of addresses for mail qualifying for postal discounts.
02/05/2024
Intelligent Mail® Package Barcode (IMpb) ACS™ Technical Guide
Technical guide for users of Intelligent Mail® Package Barcode (IMpb) Address Change Services (ACS). Includes a solution overview, features, participation requirements, and service endorsement options.
01/18/2024
Traditional ACS™ with Shipper Paid Services Technical Guide
This document is a guide that provides technical information about Traditional ACS™ with shipper paid services.
12/21/2023
Informed Delivery API Technical Specifications v4.2.3
Technical Specs are based on v4.2.0 of the XML schemas.
This is the Technical Specifications guide for the Informed Delivery API - Release 4.3 on 3/30/2023
12-21-23 - New version to fix a few minor typos.
12/06/2023
PostalOne! Release 59.0.0.0 Mail.XML PrePROD WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ PrePROD Release 59.0.0.0
12/06/2023
PostalOne! Release 59.0.0.0 Mail.XML PROD WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ PROD Release 59.0.0.0
12/06/2023
PostalOne! Release 59.0.0.0 Mail.XML TEM WSDLs
This ZIP file contains the Web Services Description Language (WSDL) and XML Schema Definition (XSD) files for Mail.XML™ TEM Release 59.0.0.0
12/06/2023
08/17/2023
Informed Delivery Saturation Campaign Mailer Guide
This guide outlines the requirements for participating in and submitting Saturation Campaigns via PostalOne! eDoc (Mail.dat) during the Informed Delivery Promotion.
For more in-depth details on general promotion requirements, refer to the Promotions page.
06/27/2023
Trailing Edge Die-Cut (Ted-C) Letters Template
Template with instructions for Trailing Edge Die-Cut (Ted-C) Letters.
Template must be printed at "actual size".