The United States Postal Service (USPS) has implemented changes that may affect the postmark date applied to mailed payments and other time-sensitive documents. 

Effective December 24, 2025, USPS added new provisions to the Domestic Mail Manual regarding postmarks and postal possession and announced operational changes to the transportation and processing of mail. Under these changes, the official USPS postmark date may no longer reflect the date a mail piece was deposited in a mailbox, lobby box, or even at a post office location. 

USPS postmarks now generally reflect the date a mail piece is processed at a regional processing facility rather than the date it is collected or dropped off.  As a result, mail-in payments may not receive a same-day postmark, even when deposited with USPS before a filing or payment deadline.  

Manual Postmarks

Taxpayers who mail their tax payments closer to the delinquency date should be aware that USPS processing changes may increase the risk of receiving a postmark date after the deadline. To avoid potential issues, taxpayers are strongly encouraged to mail payments well in advance of the deadline or consider alternative payment methods when available. 

Reminder: Property tax bills are due on September 1, 2026. Payments received after the annual delinquency date may be subject to penalties, interest, and additional fees as provided by law. 

Bank Bill-Pay and Mailed Check Services

Taxpayers who utilize their bank's online bill-pay service should also plan accordingly. Not all financial institutions mail payments on the same day a payment request is submitted. Depending on the bank's processing procedures, a check may be issued and mailed several days after the request is initiated. Initiating a bill-pay request too close to the due date may result in delayed delivery and additional charges as prescribed by law.  

Union County Tax Administration encourages all taxpayers to plan ahead and allow ample time for mailing and processing to ensure timely payment of taxes.