If you haven’t filed your 2010 personal income taxes yet, this is your 30 day letter (even though I am not the IRS). Assuming you or your tax preparer filed form 4868 (extension to file individal income taxes) you have until October 15 (actually October 17 because the 15th is a Saturday) to get everything filed. If you file after the extension date and you owe taxes, the penalty changes from half of a percent a month (late payment penalty) to 5% a month (late filing), so don’t do it. At least file the return even if you can’t pay the tax and ask for an installment agreement to make monthly payments on the tax due.