Page 1: income
Lines include 1a gross receipts or sales, 1b returns and allowances, 2 cost of goods sold, 4 net gain from Form 4797 and 5 other income, ending with line 22 ordinary business income or loss.
1120-S
U.S. Income Tax Return for an S Corporation
- Agency
- IRS
- Revision
- 2025
- Fillable fields
- 390
- Pages
- 5
- Official source
- IRS form page
- Checked
- October 14, 2026
Form 1120-S: U.S. Income Tax Return for an S Corporation
Form 1120-S is the annual return an S corporation files to report its income, deductions, gains, losses and credits. The corporation passes those items through to its shareholders, who report them on their own returns using a Schedule K-1.
This page covers the 2025 form and its 2025 instructions. The IRS says to file it if your corporation, or other entity, elected S status on Form 2553, the IRS accepted the election, and the election is still in effect. Do not file Form 1120-S for any year before the election takes effect, and do not file it at all unless Form 2553 has been filed or is attached.
You can fill out Form 1120-S on this page, in your browser, with no account.
What's on Form 1120-S
Page 1: deductions
Officer compensation (line 7), salaries and wages (8), repairs, bad debts, rents, taxes and licenses, interest, depreciation, depletion, pension plans, employee benefits and other deductions.
Page 1: tax and payments
Taxes on lines 23a to 23c, an estimated tax penalty on 25, the amount owed on 26, an overpayment on 27 and the credit or refund lines 28a to 28e.
Schedule B
Other information questions, for example constructive ownership and the business interest expense election.
Schedule K and Schedule K-1
Schedule K totals the shareholders' pro rata share items. Each shareholder receives a K-1 with their own share.
Schedules L, M-1 and M-2
Schedule L is the balance sheet per books. M-1 reconciles income per books with income per return. M-2 analyzes the accumulated adjustments account and related balances.
How to fill out Form 1120-S
- 1
Header items
Enter the corporation's name, address and EIN, and the date the S election took effect. Item F is total assets, which also decides where you file.
- 2
Income
Enter gross receipts, returns, cost of goods sold and other income, and carry the result to line 22 after deductions.
- 3
Officer compensation and wages
Report officer pay on line 7 and other pay on line 8. The instructions caution about these entries, so read that section before you finalize them.
- 4
Other deductions
Complete each deduction line that applies and total the rest on line 20 with a statement.
- 5
Tax, payments and refund
Enter any entity-level tax on lines 23a to 23c, then the amount owed or overpayment on lines 26 to 28.
- 6
Schedule K-1 for each shareholder
Prepare one for every person who was a shareholder during the year and furnish it to them.
- 7
Schedules B, L, M-1 and M-2
Answer the questions and complete the balance sheet and reconciliations that the instructions require.
- 8
Sign and date
See the signature rules below.
Why fill Form 1120-S on indox
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Deadlines, where to file and penalties
Due date
The 15th day of the 3rd month after the tax year ends. For calendar-year 2025 returns that was March 16, 2026, because March 15 fell on a Sunday.
Extension
File Form 7004 by the regular due date.
Where to file
It depends on the state of the principal business and the total assets in item F. The instructions give Ogden, Utah and Kansas City, Missouri as the main addresses, and P.O. Box 409101, Ogden for foreign or territory filers.
E-filing
For returns filed on or after January 1, 2024, S corporations must e-file if they file 10 or more returns of any type in a calendar year. A hardship waiver can be requested.
Late filing penalty
A monthly penalty applies for each month or part of a month, up to 12 months, multiplied by the number of shareholders during any part of the year. If tax is due, a percentage of the unpaid tax is added. Check the instructions for current amounts.
Late or incorrect K-1s
A separate per-schedule penalty applies, higher if the failure is intentional.
Who signs
The president, vice president, treasurer, assistant treasurer, chief accounting officer or another authorized officer. A receiver or trustee signs for a corporation in receivership, with a copy of the court order. A paid preparer also signs with a PTIN.
Related forms
2553
Election by a Small Business Corporation (Under Section 1362 of the Internal Revenue Code)
100 fields, 4 pages
1120-S
Shareholder’s Share of Income, Deductions, Credits, etc.
114 fields, 1 page
1120
Capital Gains and Losses
48 fields, 1 page
7004
Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns
26 fields, 1 page
SS-4
Application for Employer Identification Number
89 fields, 2 pages
Who needs to fill out Form 1120-S?
Official sources and the blank
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Questions about Form 1120-S
Who has to file Form 1120-S?
A corporation or other entity that elected S status on Form 2553, had the election accepted and still has it in effect.
When is Form 1120-S due?
The 15th day of the 3rd month after the tax year ends, moved to the next business day when it falls on a weekend or holiday.
What is Schedule K-1 for?
It shows each shareholder's share of the S corporation's items, which they use on their own return.
Do S corporations have to e-file?
Yes if they file 10 or more returns of any type in a calendar year, unless a hardship waiver is granted.
How do I get an extension?
File Form 7004 by the regular due date.
Can I file Form 1120-S before my election is approved?
The instructions say not to file for any year before the election takes effect, and not to file at all unless Form 2553 has been filed or is attached.