USPS changes and important tax information for 2025
In August 2025, the US Postal Service made a change to how mail is being postmarked. Most letters are no longer postmarked the day they are brought to the post office; instead, they are postmarked the next day when they’re processed at a regional mail facility.
This means:
- Mail sent Monday–Friday at a local post office will likely show a postmark one day later.
- Mail sent on Saturday won’t be processed until Monday, so the postmark could be two days later.
- If Monday is a holiday, the delay could be three days.
This is important because many laws rely on the postmark date as proof of mailing. If you’re sending tax payments or other time-sensitive documents, mail early to avoid penalties.
For more information on the USPS change, visit: https://www.wislawnow.com/2025/11/postmark-changes-at-the-post-office-and-late-mail/
Important Tax Information
Dates to remember:
- December 31 – (Optional) Pay taxes in-full before December 31 and take advantage of the property tax deduction for that year’s tax return
- January 31 – First installment or pay in full is due. (January 30 for those paying in-person at the Municipal Services Building (MSB))
- July 31 – Second installment is due to Outagamie County.
Ways to pay:
- Mail (Send early!)
- Online via e-check, credit or debit (more information here)
- In-person during normal operation hours via check, credit, or debit
- In-person payments can be made at the Municipal Services Building located at 144 W. 2nd Street. during normal operation hours (Monday-Friday 8:00 AM-4:00 PM).
- Please note the credit card processing company charges a 2.50% fee for credit payments and a $3.50 fee for debit payments. There is no fee for tax payments made with e-check.
Who to contact with questions about your tax bill:
- Outagamie County – Michelle Uitenbroek, Finance Director – 920.832.1680
- Kaukauna School District – Chris McDaniel, Director of Operations and Finance – 920.759.6109
- City of Kaukauna – William Van Rossum, Director of Finance – 920.766.6372
- Fox Valley Technical College – Amy Van Straten, Vice President of Administration – 920.735.4871
Additional resources: