Filing Season Open: January 29, 2024. Filing Season Deadline: April 15, 2024.This gives you until October 15 to file without penalties. An extension request must be submitted on or before the date the municipal income tax return is due. Download and complete a Form 32 EST-EXT. You'll receive an electronic acknowledgment once you. If you need more time to file your Ohio tax return, file a federal extension. When you later file your Ohio return, answer Yes to the question. You may also request an extension of time to file without a federal extension. Extensions - An automatic 6-month extension is granted if a federal extension is filed.