Can I File a Late Tax Return Without a Penalty?

If you are owed a refund, there is no penalty for filing late — but you must file within 3 years of the original due date to claim it. If you owe taxes, the failure-to-file penalty is 5% of unpaid taxes per month (up to 25%), which is far larger than the failure-to-pay penalty of 0.5% per month. Filing an extension by April 15 eliminates the failure-to-file penalty but not the failure-to-pay penalty. If you have reasonable cause for filing late (serious illness, natural disaster), you can request penalty abatement. The most important thing is to file, even if you can't pay — not filing is always more costly than filing late.