Effective January 18, 2026, the Postal Service™ will revise Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM®), section 204.1.0, to clarify Intelligent Mail® barcode (IMb®) standards and ensure that they are consistent with each other in the DMM.
The Postal Service is revising the following under section 204.1.0 as follows:
n The title of section 204.1.1 and the text by adding the eligible processing categories (shapes) for consistency and clarity.
n The title of section 204.1.2 for clarity.
n The title of section 204.1.2.2 and the text to provide resource information.
n The text of section 204.1.3.1 to clarify the standard and ensure that the text is consistent with other text in the DMM regarding these standards.
Although these revisions will not be published in the DMM until January 18, 2026, these standards are effective immediately.
Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM)
* * * * *
200 Commercial Mail Letters, Cards, Flats, and Parcels
* * * * *
204 Barcode Standards
1.0 Standards for Intelligent Mail Barcodes
[Revise the title and text of 1.1 to read as follows:]
1.1 Definition
An Intelligent Mail barcode (IMb) is a USPS-developed method to encode ZIP Code information on post cards and letter-size and flat-size mailpieces that automated sorting machines can read for sorting. An IMb also encodes other tracking information.
[Revise the title of 1.2 to read as follows:]
1.2 Specifications
* * * * *
[Revise the title and text of 1.2.2 to read as follows:]
1.2.2 Specification Resource
Complete specifications for Intelligent Mail barcodes are available on the Intelligent Mail Barcode (IMb) page on PostalPro at postalpro.usps.com/mailing/intelligent-mail-barcode. The IMb page includes the Intelligent Mail Barcode Technical Resource Guide, which provides details on how to encode the routing code and tracking code into an Intelligent Mail barcode, and required specifications for barcode dimensions and spacing; clear zone; skew and rotation tolerance; and print characteristics. The assignment of a Barcode Identifier, Service Type Identifier, and Mailer ID is also described on the IMb page.
1.3 Reflectance
1.3.1 Background Reflectance
[Revise the text of 1.3.1 to read as follows:]
The area of the mailpiece where the barcode is located must be uniform in color. When measured with a Postal Service envelope reflectance meter or equivalent, the minimum reflectance from the background area must be at least 50 percent in the red portions and 45 percent in the green portions of the optical spectrum.
[Delete the text of items a. and b. of 1.3.1 in their entirety.]
* * * * *
The Postal Service will incorporate these revisions into the next edition of the online DMM, which is available via Postal Explorer® at pe.usps.com.
— Product Classification,
Product Solutions, 11-27-25
