Will be held liable for the unpaid back taxes of my ex-spouse?

If you filed a joint tax return (or didn't file a return at all) and your spouse was dishonest with you about the tax liability that was owed, it may be possible that the IRS will later come back and try to collect that tax debt from you. if you were married at the time and your name was on the return or the taxes were accrued while you were part of the marital unit, this could mean you may end up facing a large tax bill that you knew nothing about and had nothing to do with racking up.

In this case, you generally have two different options: you are either going to have to just pay the bill to avoid consequences like liens being placed on your property or other collection activities, or you are going to have to petition the IRS for innocent spouse relief. Innocent spouse relief may be available in certain instances if you can prove that you followed a joint tax return with your spouse that resulted in the unpaid taxes, and if you can prove that you were not aware of whatever error or errors were made on the return that resulted in the taxes not being paid. The IRS provides a specific form for those seeking this type of relief, called form 8379. 

To get help obtaining the correct form and proving your case to the IRS so you don't end up stuck with the bills of your spouse, it is in your best interests to consult with a lawyer.