Unlike those who file for returns where money is owed, there is no penalty for filing a late return when you’re actually owed a refund.
But there are some catches. If you haven’t filed for 2010 and/or 2011 yet, the IRS might hold on to that refund until you do so. And if you owe anything to the IRS or to your state tax agency, that three-year-old refund may be used to pay off that debt. Same goes for unpaid child support or past due student loans.