Part 100 - INCOME TAX
- Subpart A - TAX IMPOSED (§§ 100.2000 — 100.2060)
- Subpart B - CREDITS (§§ 100.2100 — 100.2199)
- Subpart C - NET OPERATING LOSSES OF UNITARY BUSINESS GROUPS OCCURRING PRIOR TO DECEMBER 31, 1986 (§§ 100.2200 — 100.2250)
- Subpart D - ILLINOIS NET LOSS DEDUCTIONS FOR LOSSES OCCURRING ON OR AFTER DECEMBER 31, 1986 (§§ 100.2300 — 100.2360)
- Subpart E - ADDITIONS TO AND SUBTRACTIONS FROM TAXABLE INCOME OF INDIVIDUALS, CORPORATIONS, TRUSTS AND ESTATES AND PARTNERSHIPS (§§ 100.2405 — 100.2490)
- Subpart F - BASE INCOME OF INDIVIDUALS (§§ 100.2510 — 100.2590)
- Subpart G - BASE INCOME OF CORPORATIONS (§§ 100.2655 — 100.2680)
- Subpart H - BASE INCOME OF TRUSTS AND ESTATES (§§ 100.2770 — 100.2775)
- Subpart I - BASE INCOME OF PARTNERSHIPS (§ 100.2850)
- Subpart J - GENERAL RULES OF ALLOCATION AND APPORTIONMENT OF BASE INCOME (§§ 100.3000 — 100.3020)
- Subpart K - COMPENSATION (§§ 100.3100 — 100.3120)
- Subpart L - NON-BUSINESS INCOME OF PERSONS OTHER THAN RESIDENTS (§§ 100.3200 — 100.3220)
- Subpart M - BUSINESS INCOME OF PERSONS OTHER THAN RESIDENTS (§§ 100.3300 — 100.3600)
- Subpart N - ACCOUNTING (§§ 100.4100 — 100.4500)
- Subpart O - TIME AND PLACE FOR FILING RETURNS (§§ 100.5000 — 100.5080)
- Subpart P - COMPOSITE RETURNS (§§ 100.5100 — 100.5180)
- Subpart Q - COMBINED RETURNS (§§ 100.5200 — 100.5280)
- Subpart R - Payments (§ 100.6000)
- Subpart S - REQUIREMENT AND AMOUNT OF WITHHOLDING (§§ 100.7000 — 100.7095)
- Subpart T - AMOUNT EXEMPT FROM WITHHOLDING (§§ 100.7100 — 100.7120)
- Subpart U - INFORMATION STATEMENT (§ 100.7200)
- Subpart V - EMPLOYER'S RETURN AND PAYMENT OF TAX WITHHELD (§§ 100.7300 — 100.7390)
- Subpart W - ESTIMATED TAX PAYMENTS (§§ 100.8000 — 100.8010)
- Subpart X - COLLECTION AUTHORITY (§§ 100.9000 — 100.9020)
- Subpart Y - NOTICE AND DEMAND (§ 100.9100)
- Subpart Z - ASSESSMENT (§§ 100.9200 — 100.9210)
- Subpart AA - DEFICIENCIES AND OVERPAYMENTS (§§ 100.9300 — 100.9330)
- Subpart BB - CREDITS AND REFUNDS (§§ 100.9400 — 100.9420)
- Subpart CC - INVESTIGATIONS AND HEARINGS (§§ 100.9500 — 100.9530)
- Subpart DD - JUDICIAL REVIEW (§ 100.9600)
- Subpart EE - DEFINITIONS (§§ 100.9700 — 100.9750)
- Subpart FF - LETTER RULING PROCEDURES (§ 100.9800)
- Subpart GG - MISCELLANEOUS (§§ 100.9900 — 100.9910)