Some taxpayers are facing important Internal Revenue Service (IRS) deadlines in October. Missing IRS deadlines can carry financial consequences. Failure to file and pay a tax return on time can result in a penalty of 5 percent of taxes owed for each month or partial month the return is late. Interest may also accrue on unpaid penalties, increasing the total amount owed. If you were granted a filing extension earlier this year, your 2024 federal tax return must be filed by October 15, 2025. The