I started my return with my itin, becuase i have an itin, but my w2 has the fictious social i use for work, so when filling out the w2 info on the system i put the social as it appears on the w2. But then on my 2016 w2 it has my itin so i put the itin when filling out the w2 form. Am i supposed to use the social for both or the itin for both. Or do i go by whatever the w2s have? I am mailing my returns so i am affraid they will come back.