Effective July 12, 2026, the Postal Service™ will revise Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM®), section 602.11, to clarify the standards for Plus One mailpieces.
Although the Postal Service will not publish these revisions in the DMM until July 12, 2026, these standards are effective immediately.
Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM)
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600 Basic Standards for All Mailing Services
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602 Addressing
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11.0 Commercial Mail Plus One Mailpieces
11.1 Definition
[Revise the second sentence of the introductory text of 11.1 to read as follows:]
***The host mailpiece must meet the applicable basic standards of a USPS Marketing Mail saturation letter or saturation flat, as specified in 245.6.0 and 245.9.0, and automation standards with a correct mailing address and Intelligent Mail barcode. (Flats entered at a DDU are exempt from the IMb requirement.)***
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11.3 Documentation
[Revise the text of 11.3 to read as follows:]
When USPS requests, Plus One mailpiece mailers must provide standardized documentation according to 203.3.0 to establish that the mailpieces meet applicable distribution standards. Spoilage of host pieces may affect eligibility to mail Plus One pieces. Documentation must show that at least 90 percent of host pieces are saturation mail. The remaining 10 percent must be high density or high density plus. The following also apply:
a. The total number of Plus One pieces must be less than or equal to the number of host pieces.
b. For letters, the full automation address with IMb must be included on both pieces (Host Saturation Marriage letter and Plus One).
c. For flats, the full automation address with IMb must be generated and submitted in documentation for both pieces (Host Saturation Marriage Flat and Plus One) but is only required to appear on the Plus One card.
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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, 6-25-26
