UPDATE: US Postal Service Clarifies New Rules on Postmark Dates
- HFM CPAs + Business Advisors
- Feb 19
- 2 min read
The U.S. Postal Service has issued an important update clarifying its rules on postmarks and proof of mailing dates, a topic we recently covered in our article, Postmarks No Longer Guarantee Proof of Mailing Date.
What's New?
The Postal Service has added a new section, 608.11, "Postmarks and Postal Possession," to the Domestic Mail Manual (DMM). This update is designed to improve public understanding of postmarks and their relationship to the date of mailing. Key points:
Defines postmarks: The new section clarifies what qualifies as a postmark and identifies the types of Postal Service markings that meet this definition.
Describes when postmarks are applied: It outlines the circumstances under which postmarks are applied to mail.
Advises on proof of mailing: how customers can obtain evidence of the date the Postal Service accepts possession of their mailings.
Describes which services prove the date of postal acceptance, such as a Certificate of Mailing, Registered Mail and Certified Mail.
Important Note: This new language does not change any existing postal operations or postmarking practices. Instead, it's intended to provide clarity and transparency for customers who rely on postmarks for legal, tax, or business purposes.
Why This Matters
For taxpayers, businesses, and anyone who relies on postmarks to prove timely filing or mailing, understanding these rules is critical. As we noted in our previous article, postmarks are often used as proof of mailing dates for tax returns, legal documents, and other time-sensitive materials. This clarification from the Postal Service helps ensure you know what to expect—and how to protect yourself.
Review the new guidance to understand what qualifies as a postmark and how to obtain proof of mailing.
Consider certified mail or other tracking services for important documents to ensure you have verifiable proof of mailing dates.
Consult with your tax or legal advisor if you have questions about how these rules affect your filings or deadlines.
Need Help?
HFM CPAs is committed to keeping you informed about important changes that affect your tax compliance and business operations. If you have questions, contact HFM CPAs for guidance.
HFM CPAs provides specialized accounting, tax, and assurance services to individuals and businesses across Connecticut and Rhode Island.
