03/05/2026
Intelligent Mail Matrix Barcode (IMmb) Technical Specifications
Shipping labels on irregularly-shaped packages, softpacks, and polybags can easily become distorted or creased during automated parcel processing making reading the traditional, linear IMpb barcode challenging to scan. USPS has developed the IMmb to help overcome these challenges and improve package visibility. IMmb barcodes contain the same data as is in the IMpb barcode; however, they use a more robust, space-efficient robust barcode symbology for encodation. The smaller barcode footprint allows two IMmb barcodes to be added within unused areas of existing standard shipping labels. The result is redundancy of the barcode data giving sorters two additional chances to read the barcode.
The US Postal Service® requires IMmb barcodes on all package shipping labels.
01/29/2026
12/12/2025
12/05/2025
11/12/2025
11/12/2025
11/12/2025
11/10/2025
10/31/2025
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.
06/27/2025
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.
06/10/2025
06/10/2025
05/07/2025
06/20/2024
TED-C Mailpieces & Informed Delivery®
To ensure die-cut visibility for Informed Delivery® recipients, the leftmost edge of the die-cut extension must be in Zone C of the TED-C Letter Template. If the die-cut extension's leftmost edge is not in ZONE C, it may be acceptable to mail, but there may not be any visibility of the die-cut in Informed Delivery® for recipients.
06/20/2024
Trailing Edge Die-Cut (TED-C) Process for Eligibility at Automation Letter Prices
This advisory provides the process for getting approval to mail a non-rectangular trail edge die-cut (TED-C) letter-size mailpieces at the applicable automation letter prices.
06/14/2024
06/14/2024
05/07/2024
2024 Informed Delivery Promotion Technical Implementation-v4.3
This document outlines the technical requirements needed to successfully claim the Informed Delivery discount through PostalOne! eDoc.
12/12/2023
12/12/2023
10/04/2023
Informed Delivery Promotion - Submission Checklist
If you are having trouble with your Informed Delivery Promotion discount not applying to postage, please utilize this checklist. The checklist can help you identify the why your discount may not be applying.
09/26/2023
Retail Distribution Codes (RDC) Data Dictionary
This document contains the file format of the RDC Assignment files and the logic to determine the correct Retail Distribution Code (RDC).
08/17/2023
Informed Delivery Promotion eDoc Embedded Campaign Types and Threshold Validations
This document outlines the different campaign types embedded through PostalOne! eDoc and a summary of the threshold validations for each when participating in the Informed Delivery Promotion.
08/17/2023
Informed Delivery Saturation eDoc Scenarios
This document contains scenarios for Saturation Campaign mailings.
08/17/2023
06/21/2023
06/15/2023
2023 Informed Delivery Promotion Technical Implementation-v4.2
This document outlines the technical requirements needed to successfully claim the Informed Delivery discount through PostalOne! eDoc.
06/09/2023
05/12/2023
03/21/2023
Informed Delivery API XML Schemas-Release 4.3_v4.2.0 3-30-2023
This is a ZIP file of the XML schemas for the 4.3 release of the Informed Delivery API.
The schema version used for this release is 4.2.0.
01/10/2023
11/28/2022
09/07/2022
Informed Delivery API XML Schemas-Release 4.1.0_9-1-2022
This is a ZIP file of the XML schemas for the 4.1.0 release of the Informed Delivery API.
08/30/2022
08/30/2022
08/29/2022
Labeling List Changes Effective October 1, 2022
Effective October 1, 2022, we are revising Labeling List(s) L001, L007, L012, L014, L015, L201, and L606 to reflect changes in mail processing operations. Mailers are expected to label according to these revised lists for mailings that are inducted on or after the October 1, 2022, effective date, but no later than November 30, 2022, expiration date. The changes will be published in the Postal Bulletin, Issue #22607.
06/27/2022
Labeling List Changes Effective August 1, 2022
Labeling List Changes
Effective August 1, 2022, we are revising Labeling List(s) L006, L007, L012, and L606 to reflect changes in mail processing operations. Mailers are expected to label according to these revised lists for mailings that are inducted on or after the August 1, 2022, effective date, but no later than September 30, 2022, expiration date. The changes will be published in the Postal Bulletin, Issue #22602.
Labeling Lists
L001 5-Digit Scheme - Periodicals, Standard Mail, and Package Services Flats and Irregular Parcels
Changes
No Changes to L001
Newly Added
No Additions to L001
Deleted
No Deletions from L001
06/13/2022
06/07/2022
06/01/2022
Informed Delivery API Technical Specifications v4.0.1 6-1-2022
This is the Technical Specifications guide for the Informed Delivery API - Release 4.0.1
06/01/2022
Informed Delivery API XML Schemas-Release 4.0.1_6-1-2022
This is a ZIP file of the XML schemas for the 4.0.1 release of the Informed Delivery API.
05/27/2022
Labeling List Changes Effective July 1, 2022
Effective July 1, 2022, we are revising Labeling List(s) L001, L006, L007, L012, L201, L606, and L607 to reflect changes in mail processing operations. Mailers are expected to label according to these revised lists for mailings that are inducted on or after the July 1, 2022, effective date, but no later than August 31, 2022, expiration date. The changes will be published in the Postal Bulletin, Issue #22600.
03/22/2022
03/03/2022
Labeling List Changes Effective April 1, 2022
Effective April 1, 2022, we are revising Labeling List(s) L006, L012, L201, and L606 to reflect changes in mail processing operations. Mailers are expected to label according to these revised lists for mailings that are inducted on or after the April 1, 2022, effective date, but no later than May 31, 2022, expiration date. The changes will be published in the Postal Bulletin, Issue #22593.
12/10/2021
USPS® Blue Collection Box Location Dataset Internal Control Document
The dataset contains the United States Postal Service® collection box locations and includes times when the mail is collected from these boxes.
12/10/2021
USPS® Post Office Location Dataset Internal Control Document
The dataset contains the United States Postal Service® Post Office locations including the services provided and hours of operations. It also includes the Contract Post Office locations where USPS® products and service can be found.
12/10/2021
Mail.XML Technical Specifications R54.0.0.0 V3
This document contains information pertaining to Mail.XML and the USPS PostalOne! Release 54.0.0.0 taking place in January 2022.