January 24, 2026 - A new U.S. Postal Service rule Section 608.11 could impact when time-sensitive mail, such as tax forms and tax payments, is considered officially sent. Effective Dec. 24, 2025, mailed items are postmarked when the USPS processes them, rather than the date items are dropped in a mailbox or at a post office. A postmark refers to the date and location stamped or printed on most mailed items, indicating when and where the USPS “accepted custody” of a mail piece, according to the federal agency. The USPS said its Dec. 24 rule officially defines what postmarks are and when they are applied.
“This new 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 rule states. “Postmarks will continue to be applied to Single-Piece First-Class Mail, both letter-shaped and flat-shaped, in the same manner and to the same extent as before.”
The USPS rule means that mail is now postmarked when it is being processed and sorted at a regional postal distribution center, instead of when it is first received by the postal service.
According to the Texas Comptroller’s Office, this means items could be postmarked “several days” after they are dropped in a mailbox. “Because many federal and state laws define timely payment based on the Postal Service’s postmark, payments or reports may be considered delinquent if they are mailed too close to a deadline—even if they were, in fact, placed in a mailbox before the deadline date,” an advisory on the comptroller’s website reads.
This includes date-sensitive items sent by Texas residents and businesses, such as:
- Property tax payments
- Business Personal Property Renditions
- Ag/Timber Applications
- Property Tax Protest Filings
To avoid possible late penalties or items being considered delinquent, the comptroller’s office encourages Texans to mail items early and use online systems, when available, to submit payments or reports. Taxpayers can also take their mail into thelocal post office and request that the item be hand-stamped for free, according to the USPS. Customers can also purchase a certificate of mailing, which is similar to a receipt, for official proof of when the postal service first received their item. Dates to know
- Jan. 31: Deadline for Texas property taxpayers to pay 2025 property taxes without penalties.
- April 15: Deadline for 2026 BPP Renditions/Extension Request to be received in the Shelby County Appraisal District Office, unless an extension request of 30 days was received by this date.
- April 30: Deadline for Ag/Timber Special Use Valuation Applications to be received as well as some exemption applications such as religious organizations, nonprofit water supply or wastewater corporations, private schools, certain charitable organizations and other nonprofit organizations.
- May 15: Deadline for 2026 BPP 30 day extension requested renditions to be received.
