Public Accountability Report

The primary responsibility of the Illinois Department of Revenue (IDOR) is to serve as the tax collection agency for state and local government. The department also oversees the state's local property tax system and through June 30, 2023 functioned as the funding agent for the Illinois Housing Development Authority (IHDA). In fiscal year 2024, the IHDA funding agent role transferred to the Illinois Department of Human Services. IDOR is responsible for administering 82 tax laws, including the authorization to collect certain taxes on behalf of local governments. In fiscal year 2025, the department processed more than 6.3 million individual income tax returns and 4.3 million business tax returns. Its tax operations are divided into five primary areas of supervision: Account Processing, Taxpayer Services, Audits, Collections, and Administrative Services. These operating areas generate approximately $70.1 billion for state and local government. Tax revenues come from three key sources: (1) individual and corporate income taxes; (2) sales and use taxes; and (3) excise taxes, including taxes on liquor, cigarettes, public utilities, hotel occupancy, motor fuel, coin-operated amusement devices, bingo, and real estate transfers. IDOR also assists local governments with property tax responsibilities and tax oversight functions. This includes the administration and supervision of the state's $38.5 billion local property tax system. The department issues county equalization factors to ensure uniform property assessment levels throughout the state and assists local offices with their property tax responsibilities.