USPS Policy Change on Postmarks May Affect Property Tax Payments

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(Brown County, Wis.) – The Brown County Treasurer’s Office is encouraging residents who pay their property tax bills by mail to be aware of a recent U.S. Postal Service policy change that may affect when envelopes are postmarked. ​In August 2025, the Postal Service instituted a nationwide change as to when a postmark is affixed to incoming mail. Instead of postmarks being affixed when the item is first touched by the Postal Service, postmarks are now stamped at regional sorting centers.

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“That means your postmark could be several days after you put it in your mailbox,” says Brown County Treasurer Ray Suennen. “In other words, if you plan to pay your property taxes by mail, don’t wait until right before the deadline to put it in the mail.” Many federal and state laws define timely payment based off the USPS postmark, meaning payments may be considered delinquent if they are mailed too close to the deadline – even if they were, in fact, placed in a mailbox before the deadline.

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To avoid this issue, Suennen encourages Brown County property taxpayers to mail payments earlier, or to pay online to avoid becoming delinquent and accruing substantial late fees. 

 

“While Credit/Debit card payments and E-checks come with a service fee, it could be a great option for people who are concerned that they are mailing their payment too close to the deadline and want to make sure that they are not going delinquent,” says Suennen.