If, after you file your first extension, you find that you need more time, you can file an additional extension. The additional extension gives you until October 17th to file your actual return.
When you file for an additional extension, you need to give a reason. Unlike the four-month extension that's granted to everyone as a matter of course, the additional extension is only available if you can convince the IRS that you need it.
For example, you can get an additional extension if:
You're still waiting for a tax document such as a partnership K-1.
A serious illness interfered with preparation of your return.
You can't get professional help in time to file your return on time.
Your preparer cannot prepare your return, for reasons beyond his or her control (preparer inconvenience will not be sufficient, according to the IRS).
The IRS will not look too kindly on a claim that the dog ate your K-1's.
Click the Take Me To... button.
Scroll down to the Miscellaneous section and select Additional Extension.
Click the Whole Form button and make your entries directly on Form 2688.
Once your done, click the Print button to print the form.
Send the completed form to the same IRS address where you mailed your first extension.
Notes:
Make sure to explain the reason with adequate detail and make sure you allow the IRS enough time to respond before August 15, 2006.
Except in cases of undue hardship, you must file the first extension (for an extension of time to file until August 15) before filing for an additional extension (an extension of time to file until October 17).