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Possible online services disruption due to Internet related outage

A worldwide technology outage is causing disruption to some State of Illinois online systems.  We are aware of this issue and are diligently working on restoration.

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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 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.

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