Do you know each other? <a href=" http://www.sanalotobus.com/polyclover-wipes.html#notwithstanding ">polyclover wipes </a> Amending past returns is optional, so those who would owe more tax by filing jointly don't have to do anything. You can also choose which returns to amend depending on what benefits you most -- so you could opt to amend returns for 2010 but not 2011, for example. And only couples who are married can file jointly -- people in domestic partnerships or civil unions aren't eligible for retroactive refunds at this time.