The final due date for all December 31, 2011 year-end partnership, trust and estate income tax returns is September 17, 2012. Please contact us as soon as possible so that any 2011 partnership, trust or estate income tax returns you have on extension can be completed on a timely basis.
In addition, please note that September 17, 2012 is also the final due date for filing 2011 extended corporate tax returns for corporations with a December 31, 2011 year-end.  
And a reminder too that if your 2011 individual income tax return is on extension until October 15, 2012 that you might have a 3rd quarterly estimate payment due on September 17. Please contact us to make sure that has been considered.