Manifest Mailing System Will Retire Effective April 1

The Postal Service is retiring the manifest mailing system, by retiring manifest mail preparation along with the hard copy documentation.

The Postal Service is migrating customers to Electronic Documentation (eDoc), Full Service, Seamless, and eInduction, for Letters, Cards and Flats.

Options for Package customers are USPS Ship and Click-N-Ship.

Mailers of Letters, Cards, and Flats can reference Mail.dat / Mail.XML Technical Specifications.

Package shippers can reference Publication 199, Publication 205, and USPS Ship documentation. As a result of retiring MMS, Publication 401, Guide to the Manifest Mailing System, will no longer be available after the effective date, April 1, 2026.

The Postal Service adopts the described change to Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM), incorporated by reference in the Code of Federal Regulations. We will publish an appropriate amendment to 39 CFR part 111 to reflect these changes. Accordingly, the Postal Service amends Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM), incorporated by reference in the Code of Federal Regulations as follows (see 39 CFR 111.1).