Child Support Modification and Tax Liability

My ex wife and I entered into a separation agreement in March 2012. She kept the kids in North Carolina and I moved to another state. Because I gained residency in another state, I was able to file for divorce. We made a few modifications to the separation agreement in terms of language but the financial aspects remained the same. It also clearly stated that we would share in all tax liability until the divorce was final. Our divorce became final in January 2013. She refused to file taxes jointly which leaves me with a $6,000 tax bill. If we filed jointly as agreed we would receive a $3500 refund. Because of the tax liability, and additional expenses I am required to pay for the children, I have no additional money to care for my own household. I have to use credit cards to pay for my own living expenses. Am I able to file for a modification? The separation agreement was used to finalize the divorce so there is no actual court order. Only the separation agreement. Does she have any responsibility for the tax burden?

Without reading the separation agreement, I can’t be certain as to your arrangement, but you should consider threatening to file a breach of contract action against her for failure to follow the agreement.