Kenosha County Treasurer Warns USPS Postmark Change Could Make Your Tax Payment Late

Kenosha County Treasurer Teri Jacobson has issued a critical advisory for property owners ahead of the upcoming tax season.

A nationwide USPS policy change on postmarks may directly affect when tax payments are considered timely, potentially leading to significant penalties for unsuspecting residents.

The core of the issue is a fundamental shift in mail processing.

Previously, a postmark was often applied at the local post office where the mail was first received.

Under the new system, which began in August 2025, mail is now sent to regional sorting centers before receiving a postmark.

This procedural change means the postmark date could be one to three days, or even longer, after you place your envelope in a mailbox.

“That means your postmark could be several days after you put it in your mailbox,” Jacobson stated, emphasizing the risk.

Because Wisconsin state law defines timely payment by the official USPS postmark date, this delay could have serious financial consequences.

A payment mailed on the due date might be postmarked days later, officially making it delinquent and subject to interest and penalty charges of 1.5% per month, retroactive to February 1.

To avoid this pitfall, the Kenosha County Treasurer advises residents who pay by mail not to wait until the last minute.

Jacobson strongly encourages mailing payments several days ahead of the deadline to ensure they are processed on time.

For those seeking certainty, there are better options available.

Residents can pay their property taxes online using the E-check option, which carries a flat convenience fee of just $1.50.

“This could be a great option for people who are concerned that they are mailing their payment too close to the deadline,” Jacobson noted.

Another secure method is to take your payment to a post office counter and specifically request that it be hand-stamped or sent via certified mail.

The Treasurer’s office also cautioned against using a personal bank's online bill pay service for tax payments, as these are often sent in bulk from out-of-state processors without a postmark, creating a similar risk of arriving late.

---

Frequently Asked Questions

Why is the postmark date so important for Kenosha County tax payments?

State law uses the official USPS postmark to determine if a payment is on time. A late postmark, regardless of when you mailed it, results in the payment being classified as delinquent, which incurs steep interest and penalties.

What is the safest way to pay my property taxes now?

The most secure methods are paying online via E-check for a $1.50 fee through the county's website, or taking your payment directly to a post office to have it hand-postmarked. Mailing your payment at least a week early is also a safe bet.

Can I still mail my tax payment?

Yes, but you should do so much earlier than you have in the past. Due to the new USPS policy, waiting until the deadline is extremely risky and could result in your payment being marked as late.