Is the pro forma Form 1120 for disregarded entities the same as the full Form 1120?

No. The pro forma 1120 filed by foreign-owned single-member LLCs shows zero income and serves only as a cover sheet for Form 5472. The full Form 1120 filed by C corporations reports actual income, deductions, and tax liability.

Does my corporation need to file Form 1120 even if it had no income?

Yes. A domestic C corporation must file Form 1120 every year regardless of whether it had income or activity during the year.

What is the corporate tax rate for 2025 and 2026?

The flat federal corporate tax rate is 21%. This rate was set by the Tax Cuts and Jobs Act of 2017 and has not changed.

Form 1120 Corporate Tax Return

Form 1120 Explained: What It Is, Who Files It, and How It Works (2025-2026)

8 min readArticle

Key Takeaways

Form 1120 is the annual income tax return for all domestic C corporations
LLCs that elected C-Corp status via Form 8832 file the full Form 1120
The form has 6 pages covering income, deductions, tax computation, balance sheet, and reconciliation
The flat federal corporate tax rate is 21% (since 2017, unchanged)

What Is Form 1120?

Form 1120 is the U.S. Corporation Income Tax Return. Every domestic C corporation — including LLCs that have elected C-Corp status by filing Form 8832 — must file this form annually with the IRS. The return reports the corporation's income, deductions, credits, and tax liability for the year.

Who Must File Form 1120?

Any domestic corporation that is not an S corporation must file Form 1120. This includes traditional corporations formed by filing articles of incorporation, as well as LLCs that have elected to be taxed as C corporations via Form 8832 (Entity Classification Election).

Important distinction: Foreign-owned single-member LLCs that remain as disregarded entities file a simplified pro forma Form 1120 (with zeros) solely as a cover sheet for Form 5472. That is not the same as the full Form 1120 filed by actual C corporations.

The Six Pages of Form 1120

Form 1120 has six pages, each serving a specific purpose:

Page 1: Entity information, income, deductions, taxable income, tax liability, and payments. This is the summary page.

Pages 2–3: Schedule C (dividends received deduction), Schedule J (tax computation and credits).

Pages 4–5: Other Information — critical yes/no questions about ownership, accounting methods, business activities, Form 1099 compliance, and net operating losses.

Page 6: Schedule L (balance sheet), Schedule M-1 (book-to-tax reconciliation), and Schedule M-2 (retained earnings analysis).

The Flat 21% Corporate Tax Rate

Since the Tax Cuts and Jobs Act of 2017, all C corporation taxable income is taxed at a flat 21% federal rate. There are no longer graduated brackets for corporations. This rate applies regardless of how much income the corporation earns.

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