Return and Payment Due Dates. Note: If a due date falls on a weekend or holiday, the due date is the next business day.The payment will show on your bank statement as "STATE OF OHIO". You can delay payment until the date the liability is due. View filing due dates for Individual Tax Returns and Estimate payments. When preparing an extended return, ensure you have the following information from the extension. The amount paid with extension is reported on the city return. To receive an automatic extension to October 15, file Form 4868 with the IRS and attach a copy to the Ohio return. Write the last four digits of your Social Security number and the tax payment period on the "Memo" line of the check. If you need more time to file your Ohio tax return, file a federal extension.