Hello...
I discovered my brother-in-law filed single in his tax return starting 2006 and up to the present. He got married in 2006 in another country. Can he file an amended return and correct his status as married filing jointly? I told him his wife should get an itin since she is considered a nonresident alien who married a US citizen. Is there a deadline to file an amended return since he already filed his 2009 tax return as single? I appreciate any answer. Thanks.

It is too late for the 2006 return, but he can amend his 2009 return to file jointly and submit Form W-7 to get his wife an ITIN (her physical location is irrelevent; she could be Mars for all the IRS cares).

Once he has her iTIN, he can then amend the 2007 and 2008 return to file jointly.

Note that, if he does this, he must claim her foreign income earned in her home country on the amended return. Any additional tax can be offset using Form 2555 (Foreign Earned Income Exclusion) or Form 1116 (Foreign Tax Credit) or both.

Contact me at [email protected] if he needs professional help filing these amendments.