Effective January 18, 2026, the Postal Service™ revised Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM®) to add new section 608.11.0 to clarify postmarks and postal possession.
New section 608.11.0 defines postmarks, identifies the types of Postal Service markings that qualify as postmarks, and describes the circumstances under which those markings are applied. It also advises customers of how to obtain evidence of the date on which the Postal Service accepts possession of their mailings. This new language in the DMM 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.
These standards became effective December 24, 2025.
Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM)
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600 Basic Standmards for All Mailing Services
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608 Postal Information and Resources
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[Revise 608 by adding new 11.0 to read as follows:]
11.0 Postmarks and Postal Possession
11.1 Postmark Defined
A postmark is a marking applied by the Postal Service to a mailpiece. If applied at a retail unit, the postmark displays the name or location of the retail unit and the date on which the mailpiece was accepted at the retail unit. If applied at a processing facility, the postmark displays the name or location of the processing facility and the date of the first automated processing operation performed on that mailpiece. Where necessary, a postmark also cancels postage so that it cannot be reused.
11.2 Locations at Which a Postmark Is Applied
Postmarks are generally applied by the Postal Service via automation on machines in originating processing facilities but may also be applied manually by Postal Service personnel at those facilities, or by a Postal Service employee at a retail unit when a customer presents a mailpiece at a retail counter and requests a postmark.
a. Automated Machine-Applied Postmarks. These are applied by automated cancellation machines located in originating processing facilities, including in Regional Processing and Distribution Centers (RPDCs) and select Local Processing Centers (LPCs). Automated machine-applied postmarks cancel postage and identify the processing facility that applied the postmark and the date of the first automated processing operation performed on that mailpiece. Mailpieces prepared according to certain criteria will bypass automated cancellation to improve delivery speed.
b. Manual Postmarks on Non-Machinable Mail at Processing Facilities. Where a mailpiece that would ordinarily be postmarked on an automated cancellation machine is unable to be canceled, the Postal Service‘s common practice is to apply a manual postmark to the mailpiece at the originating processing facility. Like automated machine cancellations, these manual postmarks register the facility at which the mailpiece was received and the date that the first automated processing operation would have been performed on that mailpiece.
c. Postmarks at Retail Locations. Manual (local) postmarks are applied to mailpieces, upon a customer‘s request, free of charge at the retail counter of every Post Office, station, or branch. Manual (local) postmarks at retail locations cancel postage (if necessary), and indicate the location of the retail unit at which the postmark is applied and the date on which the mailpiece was accepted at that unit.
d. Postage Validation Imprint (PVI) Labels at Retail Locations. These are printed by Postal Service employees at retail locations and are applied to a mailpiece by a Postal Service employee upon acceptance of the piece. These labels indicate the postage paid for a mailpiece and, like manual (local) postmarks applied at retail locations, indicate the location of the retail unit at which the postmark is applied and the date on which the mailpiece was accepted at that unit.
11.3 Information Conveyed by a Postmark
Information conveyed by a postmark is as follows:
a. The presence of a postmark confirms that the Postal Service accepted custody of a mailpiece, and that the mailpiece was in the possession of the Postal Service on the identified date. However, for the reasons that are further described below, the postmark date does not necessarily indicate the first day that the Postal Service had possession of the mailpiece. Moreover, the absence of a postmark does not imply that the Postal Service did not accept custody of a mailpiece, because the Postal Service does not postmark all mail in the ordinary course of operations.
b. The name or location displayed on a postmark shows the processing facility or retail unit at which the postmark was applied. The date displayed on a postmark shows the date of the first automated processing operation performed on a mailpiece or, alternately, the date when a mailpiece was accepted at a retail unit. Because most postmarks are applied at processing facilities, they do not necessarily represent either the place at which, or the date on which, the Postal Service first accepted possession of the mailpiece. The date inscribed by a postmark applied at a processing facility may be later than the date that the mailpiece was first accepted by the Postal Service. See 11.5. for options available to customers who seek proof of the date on which the Postal Service first accepted custody of a mailpiece.
11.4 Postmarks Aligning With the Date of Acceptance
Information for customers who want their mailpiece to receive a postmark with a date aligning with the date of mailing is as follows:
a. Customers who want a postmark aligning with the date on which the Postal Service first accepted possession of their mailpiece may request, for no additional fee, a manual (local) postmark at any Post Office, station, or branch when tendering their mailpiece. Customers planning to present significant mail volume (50 or more mailpieces) for (local) postmarks should contact the postmaster or other manager in advance to ensure that adequate resources are available. Because a manual (local) postmark is applied upon acceptance at the retail counter, the date on that postmark aligns with the date on which the Postal Service first accepted possession of the mailpiece.
b. Similarly, the date on PVI labels, which are applied by Postal Service employees at the retail counter at any Post Office, station, or branch to a mailpiece for which a customer is simultaneously paying for postage and tendering the mailpiece for mailing, also aligns with the date on which the Postal Service first accepted possession of a mailpiece.
c. Please note that pre-printed labels applied by the customer prior to mailing (e.g., postage printed from Self-Service Kiosks (SSK), Click-N-Ship online postage, and meter strips) show merely that a customer has purchased postage and the date on which the postage was printed; they do not in themselves demonstrate that the Postal Service accepted the mailpiece, or the date on which any such acceptance occurred.
11.5 Services Proving the Date of Postal Acceptance
Customers who wish to retain a record or proof of the date on which the Postal Service first accepted possession of their mailpiece(s) may purchase a Certificate of Mailing. As described more fully in 503.5.0, a Certificate of Mailing is a service designed to provide evidence that individual mailpieces have been presented for mailing. As described more fully in 503.2.0 and 503.3.0, respectively, Registered Mail and Certified Mail services also provide mailing receipts for individual mailpieces.
11.6 Auxiliary Markings and Data
During the course of postal operations, the Postal Service may inscribe markings on mailpieces and/or generate scan data. Such auxiliary markings and data indicate possession of a mailpiece; however, they do not constitute evidence of the date when the Postal Service first accepted possession of a mailpiece. Furthermore, the absence of these auxiliary markings or data does not imply that the Postal Service did not accept possession of a mailpiece. A non-exhaustive list of such auxiliary markings and data include the following:
a. Identification Tags. Mailpieces processed on automated machines (i.e., mailpieces that are not deposited through bulk or commercial methods) are typically imprinted with a fluorescent identification tag. This tag encodes a variety of information, including the date on which the tag itself was applied.
b. Scans of an Intelligent Mail Barcode (IMb). As more fully described in 204.1.0, IMbs are applied by customers to mailpieces — primarily to letters, flats, and cards (as well as to certain competitive product mailings, such as USPS Priority Mail) and encode a variety of data, including the identity of the mailer, the services requested, a serial number, and a routing code. The IMb itself does not verify Postal Service possession, as it is applied by a customer before a mailpiece is tendered to the Postal Service. Rather, IMbs are typically scanned at various points in a mailpiece’s trajectory, and each scan event reflects the time and place of the scan. Where the mailer includes unique serial numbers on each mailpiece containing an IMb, IMb scan data can be used to track the processing of specific mailpieces. Commercial mailers can access IMb scan data via the Informed Visibility interface. Please note that for information generated by IMb scans to be accurate, IMbs must be properly prepared as specified in 204.1.0. Duplicate and/or illegible barcodes will compromise the availability and reliability of scan event data.
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The Postal Service incorporated these revisions into the January 18, 2026, edition of the online DMM, which is available via Postal Explorer® at pe.usps.com.
— Product Classification,
Product Solutions, 1-22-26
