When spouses file a joint tax return, each spouse is responsible for the entire tax liability. This is referred to as joint and several liability. Joint and several liability survives the divorce of the spouses even if the corresponding divorce decree states that one (1) of the spouses is solely responsible for any particular tax liability.
Equitable Relief is applicable to issues of understated tax or issues of unpaid tax in regard to items of community income or joint and several liability. Equitable Relief is available, to the requesting spouse, if he or she does not qualify for Innocent Spouse Relief or Separation of Liability Relief.
To qualify for Equitable Relief, you must meet all of the following conditions: (i) you do not qualify for Innocent Spouse Relief, Separation of Liability Relief, or relief from liability for tax attributable to an item of community income; (ii) you have an understated tax or an unpaid tax; (iii) you and your spouse or former spouse did not transfer assets to each other as a part of a fraudulent scheme; (iv) your spouse or former spouse did not transfer property to you for the main purpose of avoiding tax or the payment of tax; (v) you did not knowingly participate in the filing of a fraudulent joint tax return; (vi) the income tax liability, from which you seek relief, is attributable to an item of your spouse or former spouse or an unpaid tax resulting from your spouse’s or former spouse’s income; (vii) you timely file for relief; and (viii) taking into account all the facts and circumstances, it would be unfair to hold you liable for the understated tax or unpaid tax.
Internal Revenue Service Publication 971