How Do I Get An Extension?
An individual may file for an automatic extension through August 15, simply by completing, signing and mailing Form 4868 no later than the original due date of the return (usually April 15).
If additional time is needed, an additional extension can be requested using Form 2688, which must be filed in advance of the expiration of the first extension. If approved by the IRS, the second extension is valid through October 15th.
Note that an extension to file is *not* an extension to *pay*. Whatever tax is due as of the original due date must be estimated and shown on the extension, in order for it to be valid. In order to avoid late payment interest and possible penalties, the tax due should accompany the extension.