If the IRS receives your return or payment after the deadline date but it is postmarked on or before the deadline date, then it is considered to have been filed on time.
In the US, generally speaking, the bulk of the tax due (exactly how this is defined is complicated, but generally you're okay as long as you paid at least as much by the end of the year as you had to...
Generally you have three years in which to file a tax return for a refund. After three years, the IRS refund statute doesn't allow for issuing a refund. The three years starts on the due date of the...
FILE YOUR RETURN ON TIME ANYWAY. The federal penalty for not filing your return on time is TEN TIMES as much as the penalty for filing but not paying. The penalty for not paying is 0.5% of the unpaid...