In my personal opinion, this client should never file MFJ with this husband until after such time as he has filed all back tax returns and paid all taxes, penalties and interest due. All his taxes, penalties and interest may be much greater than the tax credits and financial aid currently available. I had a situation some years ago with a new client much like the above. Couple married in 2009 and filed MFJ with tax return prepared by another preparer. IRS took the refund she was expecting for his unfiled back taxes (1099s were issued by the contractors that hired him as a subcontractor). I filed 2004-2008 for him as single and 2010 for both of them as MFS. They are no longer clients of mine.