In 2011 I was legally separated from my wife (we did not get officially divorced until 9/2012). I believe I filed 2011 taxes as single. However, during the preliminary divorce hearing the court ordered that I had to split the tax return with her. So, I split half of the 2011 taxes with her. I just got a bill from the IRS saying that some calculations are off and I owed $2,000. Technically, if there was no error I would have gotten $2,000 less back on my taxes for 2011; meaning she would have gotten less also. Should she have to split this payment with me? Thanks in advance for any advice.