Good day!

I've been married since 2000, been to the USA 2004 as F1 visa holder, change my status to H1B October 1, 2007. I've been filing as Single since 2005, I had my first job October 25, 2004 and still working for the same company. My wife is never been to the USA, got her H4 visa but no plans yet of bringing them (my 2 kids and my wife) here as my wife is still studying. January 2008, I filed my 4th return again as single.

My question is can I amend my previous tax returns (2005, 2006, 2007 and 2008) from single to married filing jointly? Can I send the 1040X forms for each year together with W7 ITIN application form for my wife?
Also, is copy of her passport and US visa enough for W7 ITIN application to get a tax number for her?

Thanks so much!

In previous years, you were not a resident alien. Thus, you were required to file Form 1040NR. You cannot file jointly with 1040NR.