The filing of a joint income tax return has the legal effect of an irrevocable election by each spouse to be jointly and severally liable for tax reported, or properly reportable, on the return. In other words, each spouse can be held liable for the full amount of the tax, though the IRS can collect the tax only once.
Internal Revenue Code Section 6015 authorizes the IRS to grant a spouse relief from a joint return, where it is inequitable to hold the spouse bound for the return. In Revenue Procedure 2003-61, the IRS set forth the following eight factors to be weighed in deciding requests for innocent spouse relief: