Product
PDF Editor
Integrations
Solutions
By product
By industry
Features
Pricing
Support
LoginGet startedAutomate PDF workflows
IRS / Tax

Fill out 1120-S (U.S. Income Tax Return for an S Corporation) online

Form 1120-S is the annual tax return filed by S corporations. Like partnerships, S corporations are pass-through entities: the corporation reports its income, deductions, and credits, but the tax liability passes through to individual shareholders.

FreeNo signup requiredYour data stays in your browser
1120-S (U.S. Income Tax Return for an S Corporation) - simplepdf.com
Open in full page

How to fill out 1120-S (U.S. Income Tax Return for an S Corporation)

1

Enter corporation information

Fill in the corporation name, address, EIN, date of S election, business activity code, and accounting method at the top of the form.

2

Report income and deductions

Enter gross receipts on line 1a, cost of goods sold on line 2, and compute gross profit. Report deductions for officer compensation, salaries, rent, taxes, interest, and depreciation in lines 7-19. Calculate ordinary business income on line 21.

3

Complete Schedule K

Report the S corporation totals: ordinary income, rental activity income, interest, dividends, royalties, capital gains/losses, Section 179 deduction, and charitable contributions.

4

Prepare Schedule K-1 for each shareholder

Issue a Schedule K-1 to each shareholder showing their pro-rata share of income, deductions, and credits based on their ownership percentage and the days they held shares during the year.

5

Complete balance sheets and reconciliation

File Schedule L (Balance Sheets), Schedule M-1 (Reconciliation of Income), and Schedule M-2 (Accumulated Adjustments Account) if total assets are $250,000 or more.

About 1120-S (U.S. Income Tax Return for an S Corporation)

Who needs this form

Any domestic corporation that has elected S corporation status by filing Form 2553. The S corporation must file Form 1120-S even if it had no income or deductions for the year.

Where to submit

File with the IRS by the deadline listed in the latest Form 1120-S instructions (calendar-year S corporations are typically due in mid-March). Extensions are available using Form 7004; verify the current extended due date in the official instructions.

Source and content freshness

Official source (www.irs.gov)
  • Reviewed: 2026-02-16
  • Check the latest official form instructions for the filing year that applies to you.
  • Filing deadlines may shift for weekends and holidays. Verify due dates with official instructions.

Common mistakes to avoid

  • Filing late (penalty is per shareholder per month)
  • Not issuing Schedule K-1 to each shareholder by the filing deadline
  • Paying shareholder-employees unreasonably low salaries to reduce payroll taxes
  • Not tracking shareholder basis, leading to incorrect loss deductions

Got any questions?

Is this form free to fill out?
Yes. SimplePDF lets you fill out PDF forms in your browser for free. Most users can do this without creating an account. For team and business features, see our pricing plans.
Do I need to create an account?
No. You can fill out and download the form without creating an account or signing up.
Is my data secure?
Yes, you edit documents in your browser. In the free flow, SimplePDF does not process document contents on its servers. In paid plans, completed files are stored either by SimplePDF or in your own storage, based on your settings. Read our privacy policy for more details.
Is this legal, tax, or immigration advice?
No. SimplePDF provides form-filling tools and general informational content, not professional advice. Verify requirements with official instructions or a qualified professional.
Can I share a direct link to this form?
Yes! You can create a direct link to any PDF by prefixing its URL with simplepdf.com/. For example: simplepdf.com/https://example.com/form.pdf. Anyone who opens the link can fill out the form immediately in their browser. You can also embed the editor in your own website.
What is the difference between an S corporation and a C corporation?
An S corporation is a pass-through entity: profits and losses flow through to shareholders and are taxed on their individual returns. A C corporation pays corporate income tax, and shareholders pay tax again on dividends (double taxation). S corporations avoid double taxation but have restrictions on the number and type of shareholders. To elect S corporation status, file Form 2553.

SimplePDF provides a tool to fill out PDF forms. We are not affiliated with any government agency or form issuer. It is your responsibility to verify the accuracy and completeness of any information entered. SimplePDF is not liable for errors, omissions, or consequences resulting from the use of filled-out forms.

Need to handle forms at scale?

Embed SimplePDF in your own app or website. Your users fill out PDFs without leaving your platform, and you receive structured submissions.

See pricingLearn about embedding