Illinois Department of Revenue Form Instructions
- il-1065 Instructions for Form IL-1065 — Partnership Replacement Tax Return
- il-1065-x Instructions for Form IL-1065-X — Amended Partnership Replacement Tax Return
- il-1120 Instructions for Form IL-1120 — Corporation Income & Replacement Tax Return
- il-1120-st Instructions for Form IL-1120-ST — Small Business Corporation Replacement Tax Return
- il-1041 Instructions for Form IL-1041 — Fiduciary Income & Replacement Tax Return
- il-1041-sch-k-1-t-1 Instructions for Schedule K-1-T (Part 1) — Beneficiary's Share
- il-1041-sch-k-1-t-2 Instructions for Schedule K-1-T (Part 2) — Beneficiary's Share
- sch-k-1-p-1 Instructions for Schedule K-1-P (Part 1) — Partner's/Shareholder's Share
- sch-k-1-p-2 Instructions for Schedule K-1-P (Part 2) — Partner's/Shareholder's Share
- sch-ub Instructions for Schedule UB — Combined Apportionment for Unitary Business Group
- il-1040 Instructions for Form IL-1040 — Individual Income Tax Return
- il-1040-sch-cr Instructions for Schedule CR — Credit for Tax Paid to Other States
- il-1040-sch-nr Instructions for Schedule NR — Nonresident & Part-Year Resident Computation
- il-941 Instructions for Form IL-941 — Illinois Withholding Income Tax Return
- il-w-4 Form IL-W-4 — Employee's Illinois Withholding Allowance Certificate
- st-1 Instructions for Form ST-1 — Sales and Use Tax Return
- st-1-x Instructions for Form ST-1-X — Amended Sales and Use Tax Return