What is the penalty for filing taxes late? The good news is that if you're expecting a tax refund and don't file your federal income tax return on time, there's no late charge. The bad news is that you won't get your refund until you file. You have three years from the due date of your tax return to file and claim your refund. After that, the money goes back to the US Treasury. But if you owe taxes and fail to file your return, the IRS essentially starts a running tab in your name. Every 30 days, you'll be charged 5% of any unpaid tax you're required to report on your return. Even if you file within a few weeks of the deadline, the full month penalty still applies.