If you do not file your tax return by the deadline and you fail to pay on time, you will usually owe interest and penalties on the tax you pay late. Here are a few facts that you should know about these penalties.

• Two penalties may apply if you file your federal tax return late and owe tax with the return: failure-to-file penalty (for late filing) and failure-to-pay penalty (for paying late).
• Penalty for late filing (failure-to-file) is normally 5% of the unpaid taxes for each month or part of a month that a tax return is late.
• Minimum late filing penalty, if you file your return more than 60 days after the due date or extended due date, the minimum penalty for late filing is the smaller of $135 or 100 percent of the unpaid tax.
• Penalty for late payment (failure-to-pay) is generally 0.5% per month of your unpaid taxes. It applies for each month or part of a month your taxes remain unpaid and starts accruing the day after taxes are due.
• If you can’t pay, still file. In most cases, the failure-to-file penalty is 10 times more than the failure-to-pay penalty. If you can’t pay in full, you should file your tax return and pay as much as you can.
• Late payment penalty may not apply if you requested an extension of time to file your income tax return by the tax due date and paid at least 90 percent of the taxes you owe, you may not face a failure-to-pay penalty. You must pay the remaining balance by the extended due date and you will owe interest on any taxes you pay after the April 18 due date.
• If you can show reasonable cause for not filing or paying on time you may not have to pay a failure-to-file or failure-to-pay penalty.