Okay, you filed an extension. You still have six weeks before the August 16th due date. What is the hurry? No problem if you are sure you will be able to make the deadline. But if there is a chance that you might need more time, now is the time to act on it. You will have to file Form 2688 or send a letter to ask for more time. You will have to explain why you need more time and the IRS can refuse the second extension. If you are refused you will have until August 16th to get your return filed.