State C-Corporation Filing Requirements — Form 1120

2024 Tax Year Reference • All 50 States + DC • Click any row to expand full details • Sources: State DOR websites, Thomson Reuters Checkpoint, CCH State Tax Guide • Always verify at state DOR — rates, forms, and thresholds change annually

Federal 1120 Original DueApril 15, 2025 (calendar year)
Federal Extension (Form 7004)Extends to October 15, 2025 (6 months)
Federal Estimated Tax DatesApr 15 • Jun 15 • Sep 15 • Dec 15
Federal Estimated Tax FormForm 1120-W (worksheet); pay via EFTPS
Federal Safe Harbor100% of prior year tax OR 100% of current year tax
⚠ Additional State Taxes Applicable to C-Corps — Beyond Income Tax, Franchise Tax & Gross Receipts
State AMT: CA (6.65% AMT), some others — may apply even in loss years
DE Franchise Tax: Charged to ALL DE-incorporated corps ($175–$200K+) based on authorized shares or assumed par value — due Mar 1, separate from income tax
IL PPRT: IL Personal Property Replacement Tax (2.5% extra on C-corp income) — in addition to 7% IL income tax = effective 9.5% total
NY MTA Surcharge: 0.75% of allocated NY income for corps in NY Metro area — added to CT-3 filing
NYC Corporate Tax: NYC Form NYC-2 separate from NY State — applies to any corp doing business in NYC
NH BET: Business Enterprise Tax (0.55% on wages+interest+dividends paid) — creates obligation even in loss years
KY LLET: Limited Liability Entity Tax — applies to most KY entities including C-corps; minimum $175
AL BPT: Alabama Business Privilege Tax (net worth based, $0.25–$1.75 per $1K) — filed separately with Secretary of State
OR CAT: Oregon Corporate Activity Tax (0.57% of OR commercial activity >$1M) — completely separate from income tax extension
TX/OH/WA/NV/SD/WY: No corporate income tax; instead gross receipts/margin/B&O taxes — see each state's entry for details
VT Business Entity Tax: VT minimum $300 business entity tax; separate from income tax in some cases
PA CNIT: PA reducing from 9.99% → 4.99% by 2031; verify current year rate each filing season
Extension: ⚠ Separate form required ⊙ Only if payment due ✓ Auto w/ federal 7004 — N/A no income tax   Form types: Income Tax Franchise Tax Gross Receipts F&E Tax Business Privilege/Activity Add'l Tax/Surcharge
State State Returns Required & Due Dates Extension Rate / Min Tax Estimated Tax Schedule DOR
Disclaimer: This tool is for professional tax practitioner reference only. State tax laws, forms, rates, thresholds, and due dates change frequently. Always verify current requirements directly with the state DOR or through a current-year tax research subscription (Checkpoint, CCH, BNA Bloomberg). This tool does not cover local-level taxes (NYC, Philadelphia, Columbus, etc.) beyond NYC corporate tax note, or special industry taxes (insurance premium tax, financial institution tax, public utility taxes). • Federal 1120 due April 15 for calendar year. Extension via Form 7004 to October 15.