IRS Corporate Tax Return Form 1120 / 1120-S Guide
Form 1120 and Form 1120-S are the official IRS corporate tax returns used by US C-Corporations and S-Corporations to report income, deductions, and shareholder distributions.
👤 Filing Eligibility
All incorporated C-Corporations, elected S-Corporations, and LLCs electing corporate tax treatment in the US.
IRS Filing Deadline
S-Corp returns are due March 15; C-Corp returns are due April 15. Automatic 6-month extensions are available via Form 7004.
📂 Form Description
Form 1120/1120-S establishes corporate financial standing and serves as the baseline generating shareholder K-1s and state tax returns.
Our corporate tax engine parses P&L data, Balance Sheets, and Form 4562 depreciation tables, performing Schedule M-1 adjustments to assemble Form 1120 filings.
Filing Tips & Audit Alerts
- ✓Federal corporate tax is a flat 21%; California corporations must pay an annual minimum Franchise Tax of $800 regardless of net profit.
- ✓S-Corp shareholder-officers must receive reasonable W-2 salaries subject to payroll tax before taking pass-through distributions on Schedule K-1.
- ✓Reconciling book income to taxable income via Schedule M-1 and tracking shareholder basis on Schedule M-2 are essential for IRS audit readiness.
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