If you didn't submit your tax returns by the April 15 deadline, this is what the IRS recommends you do next to ensure a refund and minimize penalties.

If you file your taxes late and don’t file for an extension first, you risk being hit with additional fees for the tardy submission. The penalty amounts to 5% of the taxes owed for each month that the filing is late, up to a maximum of 25%. Under such circumstances, watch your mailbox for a notice from the IRS informing you of a late fee.