What is Form 1120 (C-Corp Annual Return)?
Form 1120 is the annual federal income tax return for US C-corporations, due 15 April for calendar-year filers (15th day of the 4th month after fiscal year-end for fiscal-year filers). Six-month automatic extension available via Form 7004.
Current Rate (Annual, calendar year default)
N/A — return only
Example
Acme Inc. (calendar year C-corp) files Form 1120 by 15 April 2025 reporting 2024 taxable income, federal corporate income tax, and any tax credits (R&D, foreign tax credit, etc.).
Related terms
A C-corporation is a US business entity taxed separately from its owners under Subchapter C of the Internal Revenue Code. It pays 21% federal corporate income tax on profits, and shareholders pay personal tax on dividends — the 'double taxation' of C-corp profits. Most VC-backed startups are Delaware C-corps.
Form 1120-S is the annual federal income tax return for US S-corporations, due 15 March for calendar-year filers. The corporation does not pay federal income tax; instead, each shareholder receives a Schedule K-1 reporting their share of income, deductions and credits.
Form 1065 is the annual return for US partnerships and multi-member LLCs taxed as partnerships, due 15 March for calendar-year filers. The partnership does not pay federal income tax; profits flow to partners via Schedule K-1.
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