When you file a joint income tax return, the law makes both you and your spouse responsible for the entire tax liability. This is called joint and several liability. Joint and several liability applies not only to the tax liability you show on the return but also to any additional tax liability the IRS determines to be due, even if the additional tax is due to income, deductions, or credits of your spouse or former spouse. You remain jointly and severally liable for the taxes, and the IRS still can collect from you, even if you later divorce and the divorce decree states that your former spouse will be solely responsible for the tax.
In some cases, a spouse (or former spouse) will be relieved of the tax, interest, and penalties on a joint tax return. Three types of relief are available to married per- sons who filed joint returns.

1. Innocent spouse relief.
2. Separation of liability relief.
3. Equitable relief.