I am on f1 visa and my wife is on f2. I want to file my tax under married filing jointly. However, I my wife is not eligible for SSN and ITIN will take 8 weeks (beyond filing deadline). I wanted to know if I can go ahead with married filing jointly if I apply for her ITIN through W7 and write "applied for" in the space for SSN (while still waiting for the ITIN) and mail the physical copy of tax return documents.