Similar to federal income tax procedures, including withholding, declaration and payment of estimated tax. Credits against tax are permitted for residents for income taxes paid in other states. Special return requirements are imposed for withholding agents and persons making payments of estimated tax. Imposed on the privilege of earning or receiving income in or as a resident of Illinois. Trusts may be either residents or nonresidents.
Residents allocate all of their income to Illinois.
Nonresidents, including corporations, allocate and apportion income. The department collects the tax and redistributes it to the local taxing bodies. Payments are similar to state income tax procedures, including payment of estimated tax. Corporations, as well as S corporations, partnerships, and trusts, are subject to annual return requirements. The return for gross receipts of January, for example, should be filed by February 20.