Illinois Revenue Department Warns Taxpayers About Postal Service Changes Affecting Tax Filings (Chicago, IL) – The Illinois Department of Revenue (IDOR) is urging taxpayers to plan ahead when mailing their tax returns this year after changes by the U.S. Postal Service could affect how filing deadlines are determined.
According to IDOR, the Postal Service has updated how postmarks are applied to mail. While the postmark will still show the date of the first automated processing operation, it may no longer reflect the day the mail was dropped off at a local post office.
State officials say the change could impact time-sensitive documents such as tax returns and payments, particularly for taxpayers who wait until the last minute to send their filings.
“Our goal is to help taxpayers avoid unnecessary stress and penalties,” said IDOR Director David Harris. “If returns are mailed, taxpayers should not wait until the last day, or they should request manual postmarks at the post office if they are mailing a return near the filing deadline.”
The state’s tax filing deadline remains Wednesday, April 15, and IDOR recommends that taxpayers mail returns earlier than usual to ensure they arrive on time.
The Postal Service will continue to provide manual postmarks at retail locations upon request, free of charge. These manual postmarks reflect the date the USPS takes possession of the mail and can serve as proof of timely filing.
Harris said the most reliable option for taxpayers is to file electronically. Illinois offers free online filing and payment options through the MyTax Illinois system at tax.illinois.gov.
Taxpayers who are not required to file electronically may also drop off returns or payments at an IDOR office, where staff can provide a date stamp confirming when the documents were received.
State officials say taking extra steps—such as mailing early, requesting a manual postmark, or filing electronically—can help taxpayers avoid delays and potential late penalties.
Additional details about the postal changes are available in guidance published by the U.S. Postal Service in the Federal Register.
Illinois Revenue Department Warns Taxpayers About Postal Service Changes Affecting Tax Filings
