Jack Sprat did pay no tax.
His wife paid all of hers.
But when they filed a joint return,
She learned she owed all of his!
This is the heart of the innocent spouse!
The innocent spouse filed a joint return with a balance due – but didn’t really create the tax obligation. S/he did everything right, paid all the proper withholding or estimated tax payments. Yet, s/he suddenly finds out that the spouse has a balance due and doesn’t have the money to pay it all.