Signing a joint tax return may result in serious implications for an innocent spouse. However, filing a joint return is a completely voluntary action and should likely be avoided in some situations. When a person signs a joint tax return, he or she creates joint and several liability. This term means that the IRS can go after either spouse to collect the full amount of any tax that is owed. Even if a divorce court finds that the tax liability rests on one spouse, the IRS does not have to honor this finding and can still pursue tax collection procedures against either spouse. In a similar fashion, a probate court's findings can also be ignored and an innocent spouse can be left to pay off the tax liability.