What if I have filed an Illinois return before, but I haven't filed one in the past few years?
If you haven't filed an Illinois tax return in the past three years then you won't have an Illinois PIN, 2011 Illinois adjusted gross income (AGI), or nine-digit zip code on file with the Illinois Department of Revenue. You can still e-file and electronically "sign" your return by entering your Illinois driver's license or state ID card information.
