On November 24, 2025, the United States Postal Service promulgated document 2025-20740, which was published in the Federal Register at 90 FR 52883. This document contained a final rule from the Postal Service, which amended 39 CFR Part 111 to add Section 608.11, “Postmarks and Postal Possession,” to the Domestic Mail Manual (DMM).
According to the USPS, this language “does not change any existing postal operations or postmarking practices but is instead intended to improve public understanding of postmarks and their relationship to the date of mailing.” The new rule became effective December 24, 2025, and despite the Postal Service’s reassurances, the new rule may cause substantial changes to how postmarking is applied to mail, which may in turn affect a variety of deadlines which are dependent upon postmark dates.
What is a Postmark?
A postmark is a marking applied by the Postal Service to a mailpiece displaying the date and location of the Postal Service facility where the mailpiece was received. It often also doubles as the cancellation of the stamp applied to the mailpiece so that it cannot be reused. Postmarks can be applied automatically by machine at a processing facility, or manually by a Postal Service employee at a USPS facility.
Historically, the American public has believed that a postmark indicated the date that a mailpiece was dropped into a mailbox or submitted at a post office counter, and historically that was generally the case. However, the Postal Service has now clarified that the Postmark will reflect the date that an envelope is first processed at an automated sorting facility, unless a manual postmark is requested at a USPS retail location.
Why Does the Change Matter?
The Postal Service has indicated that 608.11 is not a rule change, but a clarification of what the purpose and timing of a postmark has always been. However, this clarification comes at the same time as enveloped mail no longer functions the way it used to. In 2021, the United States Postal Service started implementing major infrastructure changes under the Delivering for America (DFA) plan.
The purpose of the DFA was to reduce the financial instability that had plagued the Postal Service for decades. One of the most significant developments under the DFA plan is the consolidation from nearly 200 local processing centers to just 60 regional facilities. The practical effect of this consolidation is that some mailpieces must travel further distances from the point of deposit with the Postal Service to the first regional sorting facility, where a postmark is applied.
Prior to the DFA plan, most Americans had every confidence that their mail would be postmarked on the day they deposited it in a mailbox because in almost every case, it was. However, under the DFA plan changes, this standard practice is no longer to be considered the norm, and the Postal Service is telling consumers just that with 608.11.
In response to negative public commentary in the wake of 608.11, the Postal Service has claimed that they have never offered the postmark as a way of “proving” when mail was sent. However, many governmental, legal, and administrative entities rely upon the postmark for determining whether a mailing was sent prior to a deadline.
This includes the IRS, state election boards, filings with the United States Supreme Court or Tax Court, the Equal Employment Opportunity Commission, the Social Security Administration, and state-level unemployment and licensing agencies. Tax and election law experts are already predicting that incidences of rejected mail-in ballots and late federal tax filings will increase under the new practices of the Postal Service, and both individuals and businesses need to be on alert to avoid consequences for missed mailing deadlines.
What Can You Do to Ensure Timely Postmarking?
There are a variety of steps that can be taken to reduce the possibility of a late postmark on a mailpiece. First, building in extra time to account for delays in processing by submitting time-sensitive mail early is better practice than ever before.
Second, consumers may consider utilizing an alternative to the Postal Service, such as FedEx or UPS, for time-sensitive mailings.
Finally, consumers can bring a mailpiece to a Postal Service retail location and request a manual postmark be applied by hand to their mailpiece. With changes to the Postal Service’s operations, it is more important than ever that consumers be proactive to avoid missed deadlines or legal penalties for “late” mailing.