You can file jointly and use injured spouse procedures so long as it is your debt. That's why I was asking what name is on the sales tax return,.
You don't mention where you live. As
an additional comment, the rules are sometimes different if you live in a
community property state (Arizona, California, Idaho, Louisiana, Nevada, New
Mexico, Texas, Washington and Wisconsin.) In those states, even with
injured spouse relief, the relief may not be as complete as it would be in
other states. If you live in one of those states, see IRS Publication 555 for a
more complete discussion of injured spouse in a community property state. It
can be found at http://www.irs.gov/publications/p555/ar02.html#d0e928
