Married Filing Jointly
If you and your spouse agree to file a joint return, you can elect the "Married Filing Jointly" filing status. Report all of your combined income and deductions, even if one spouse had no income or deductions. This status may provide higher standard deductions, tax benefits not available to other filing statuses and a lower overall tax due to the Internal Revenue Service. You and your spouse will be held individually and jointly accountable for any tax and penalties owed from the combined return.
Married Filing Separately
You and your spouse can file separate returns and elect the "Married Filing Separately" filing status if you do not agree to file a joint return. In general, this status will result in a combined tax due to the IRS that is higher than the "Married Filing Jointly" status and may prevent you from taking advantage of special tax benefits only provided to those who elect "Married Filing Jointly." You are only held accountable for the tax and penalties due on your return, not on your spouse's return.
Switching from Separate Returns to a Joint Return
You have three years from the due date of the first return you filed separately to switch to a joint return. Change your filing status by filing form 1040X and submitting an amended return.
Switching from a Joint Return to Separate Returns
If you file a joint return, you cannot file separate returns for the tax year immediately following the first year in which you filed the joint return. For the subsequent tax year, you can switch to separate returns. For example, if you first filed a joint return for 2010, you cannot file separate returns in 2011 and you have to wait until 2012 to file separate returns.