2010 individual US returns are due for filing by 18 April. Unless an extension is available, as in these circumstances:
a) the US citizen or resident alien is outside the US at the due date, in which case an automatic 2-month extension of time for filing is available, or
b) the individual applies for a 6-month extension of time, for 2010 returns the due date once the extension is applied for is October 17, 2011.
Individuals who qualify for, and wish to invoke the 2-month extension need not make an application for this extension. However, they must attach a statement to their tax return advising IRS that their location is outside the US at the due date for filing (18 April 2011).
Individuals wishing to invoke the 6-month extension must either
a) file form 4868 Application For Automatic Extension of Time To File U.S. Individual Tax Return by 18 April 2011 or
b) make a credit card payment of the estimated amount of 2010 tax by 18 April 2011.
Reminder: Extension of time to file is not an extension of time to pay. Any tax for 2010 is still due April 18, 2011, otherwise, interest and penalties will apply for late filing and late payment.