The proposed rule educates, formalizes, and clarifies the public understanding of postmarks within the Domestic Mail Manual (DMM) 

By Deborah Damore, Head of Postal Affairs, GrayHair Software
August 13, 2025

A notice of proposed rulemaking was published in the Federal Register on August 12th, 2025, to update the Domestic Mail Manual (DMM). The FRN addresses Postmarks and Postal Possession. 

The proposed changes to the U.S. Postal Service’s Domestic Mail Manual (DMM) aim to clarify postmark definitions, applications, and their relationship to postal possession. The proposed new section (608.11), “Postmarks and Postal Possession,” will explain what qualifies as a postmark, how markings are applied, and advise customers on options to obtain evidence of the exact date of postal acceptance. This initiative aims to educate the public about postmark information and available services, including certificates of mailing, to provide proof of mailing dates.

Some of the key areas of the Federal Register Notice are:

• Clarifying Postmark Limitations: A significant portion of the FRN focuses on the potential discrepancy between the postmark date (especially machine-applied ones) and the actual date the USPS first took possession of a mailpiece. This discrepancy is expected to become more common due to the Regional Transportation Optimization (RTO) initiative, which can delay processing and postmarking by a day or more.
• Third-Party Uses of Postmarks: The FRN acknowledges that various entities, including federal and state courts, the IRS, state tax authorities, election jurisdictions, and private sector businesses, rely on postmarks for purposes like confirming mailing and establishing the date of mailing.  
• Auxiliary Markings and Scan Data: The FRN goes on to explain that other markings (like fluorescent identification tags) and scan data (from Intelligent Mail® Barcodes) can indicate postal possession but do not necessarily prove the date of first acceptance in all states.
• Services for Proof of Acceptance: The USPS encourages customers who need definitive proof of the date of postal acceptance to utilize services like Certificates of Mailing, Registered Mail, or Certified Mail, all of which provide a receipt for the date of mailing. Manual (local) postmarks at retail locations and Postage Validation Imprinter labels (PVI) also align with the date of acceptance.
• Review Internal Policies and Update Compliance Protocols: Ensure that grace periods or deadlines based on postmarks account for potential delays due to RTO and align your documentation standards with USPS’s clarified definitions. 
• Request for Comments: The USPS is soliciting public comments on the proposed DMM revisions, particularly regarding the impact on stakeholders and suggestions for public education efforts about the new provision.

Comments are due to PCFederalRegister@usps.gov by September 11, 2025. 

In summary, the proposed rule aims to formalize and clarify the understanding of postmarks within the DMM, educate the public about their meaning and limitations, and guide customers on how to obtain verifiable proof of the date of mailpiece acceptance.

To read the full Federal Register (FRN) proposed rule, click this link.

For more information on this or other postal issues, reach the GrayHair Software team by email at engage@grayhairsoftware.com