How to File an IRS 1040 Extension
- 1). Collect the tax documents for the tax year in question. While you may request the extension because you do not have all the relevant financial information, you will need to estimate any taxes you owe. The previous year's tax data may serve as a guide.
- 2). Estimate your tax liability for the tax period for which you are requesting the extension. Subtract the amounts you paid during the tax year. Your employer will have deducted taxes from your salary. Take into account any deductions to which you are entitled.
- 3). Complete IRS Form 4868. Write in your estimated tax liability on line four. Write in your total tax payments for the year on line five and enter the difference on line six. Enter the amount you are paying on line seven.
- 4). Mail the form to the IRS with your estimated tax payment. While the extension to file is automatic, you are required to pay any taxes you may owe by the due date. If you pay less than the total taxes you owe, you will be assessed a late penalty and interest will accrue. The late payment penalty is usually one half of 1 percent of any taxes not paid by the due date. The maximum penalty can accrue up to 25 percent.