If my Illinois tax increases as a result of my federal change, how long do I have to amend and pay the additional liability?

If my Illinois tax liability increases as a result of my federal change, how long do I have to amend and pay the additional liability to the State of Illinois?

If your federal change increases your Illinois tax, you must file Form IL-1040-X and pay any additional tax within 120 days of the federal finalization date or you may be assessed a late-payment penalty. 

Submit a question