How Can You File Internal Revenue Service Extension Forms?

Taxpayers can file extension forms with the IRS electronically or by mailing the form directly to the IRS, explains TurboTax. If requesting an extension by mail, taxpayers must fill out IRS form 4868.

Common reasons a taxpayer may need more time to file his tax return include the need for additional time to track down missing tax documents, life being too busy or an unexpected life event, notes TurboTax. Taxpayers wishing to filing an extension with the IRS must still pay their taxes at the time they file the extension. It is necessary to calculate an estimated amount due and submit that payment along with the request for extension to file taxes.

If the IRS believes that any estimated tax paid is an unreasonable amount, it may not allow the taxpayer to file for an extension and may even apply a late-filing penalty. Taxpayers who underestimate the amount of tax owed must pay interest on whatever amount he fails to pay by the original filing date. If he pays less than 90 percent of the taxes he owes, he may owe a penalty of 0.5 percent of the underpayment every month until the remaining balance is paid.

Taxpayers should check with state guidelines to determine if an extension to file late is required for filing state tax returns.