Section 6015(b), relief of liability to all joint filers, is often referred to as traditional innocent spouse relief.  This is because it is a carryover of the old innocent spouse law (pre-1998).  The tests for relief under this section are:

• A joint return was filed.
• There is an understatement of tax attributable to the non-requesting spouse.
• The requesting spouse must not have constructive knowledge of the items creating the understatement.
• Considering all the facts and circumstances, it is inequitable to hold the requesting spouse liable for the understatement.
• The claim must be filed within two (2) years of the first collection activity.
• This is the most difficult section under which to achieve relief because the burden of proof is on the requesting spouse to prove they did not have so much as constructive knowledge of the items creating the deficiency.  Few requesting spouses are able to meet this test.

For taxpayers meeting the marriage test under Section 6015(c), the only reason to seek relief under this section is to receive a refund. Otherwise proceed directly to Section 6015(c).