The Illinois Tax Objection Complaint Packet is a legal document used to contest a tax assessment issued by the Illinois Department of Revenue. It is used to object to an assessment of taxes, interest, or penalties, and to protest any other action related to the assessment. The packet includes a form for the taxpayer to fill out and a set of instructions on how to file the complaint. Types of Illinois Tax Objection Complaint Packets include: 1. Form IL-1000: Used to contest an assessment of taxes, interest, or penalties issued by the Illinois Department of Revenue. 2. Form IL-1040: Used to contest an assessment of taxes, interest, or penalties issued by the Illinois Department of Revenue on an individual income tax return. 3. Form IL-1041: Used to contest an assessment of taxes, interest, or penalties issued by the Illinois Department of Revenue on a fiduciary income tax return. 4. Form IL-1042: Used to contest an assessment of taxes, interest, or penalties issued by the Illinois Department of Revenue on a corporate income tax return.