What Form 1120 is for
Form 1120 is how a corporation reports a full year of income, gains, losses, deductions, and credits to the IRS and figures the income tax it owes. You start with gross receipts, subtract cost of goods sold and business deductions, and land on taxable income. Schedule J turns that number into tax at 21%, then applies credits and payments.
Unless it is exempt under section 501, every domestic corporation files this return, even in a year with no taxable income. That includes corporations in bankruptcy and entities that elected corporation treatment on Form 8832. Some organizations file a different return instead, such as an S corporation on Form 1120-S or a foreign corporation on Form 1120-F.
Who has to file Form 1120?
All domestic corporations must file an income tax return whether or not they have taxable income, unless they are exempt under section 501. Corporations in bankruptcy are included. A domestic entity that elects to be classified as an association taxable as a corporation also files Form 1120 and attaches a copy of Form 8832 for the year of the election. An LLC with more than one owner is generally treated as a partnership and files Form 1065 instead, unless it filed Form 8832 to be treated as a corporation.
- S corporation: Form 1120-S
- Foreign corporation: Form 1120-F
- Life insurance company: Form 1120-L
- Political organization: Form 1120-POL
- Exempt organization with unrelated business income: Form 990-T
- Homeowners association electing section 528 treatment: Form 1120-H
When is Form 1120 due?
Generally you file by the 15th day of the 4th month after the end of the corporation's tax year. The same rule covers a new corporation filing a short-period return and a corporation that has dissolved, counted from the date it dissolved. If the tax year ends June 30, file by the 15th day of the 3rd month instead. A short tax year ending any time in June is treated as ending June 30. If the due date falls on a Saturday, Sunday, or legal holiday, you can file on the next business day.
Paying is a separate step. The corporation must pay any tax due in full no later than the return due date, not including extensions, and the payment must be made electronically. Estimated tax installments are due by the 15th day of the 4th, 6th, 9th, and 12th months of the tax year if the corporation expects total tax of $500 or more. Interest runs on taxes paid late even when an extension to file was granted. File Form 7004 to request an automatic extension of time to file.
Where do you send Form 1120?
The address depends on where the corporation's principal business, office, or agency is located and on its total assets at the end of the tax year. Most corporations can e-file, and any corporation that files 10 or more returns of any type during the calendar year is required to e-file. A corporation can ask for a hardship waiver in writing. If using the required technology conflicts with religious beliefs, the corporation is exempt and writes "Religious Exemption" at the top of page 1.
- Department of the Treasury, Internal Revenue Service, Kansas City, MO 64999-0012: the listed eastern and midwestern states, with assets under $10 million and no Schedule M-3
- Department of the Treasury, Internal Revenue Service Center, Ogden, UT 84201-0012: those same states with $10 million or more in assets, or under $10 million with Schedule M-3 filed
- Department of the Treasury, Internal Revenue Service, Ogden, UT 84201-0012: the listed western and southern states, any asset amount
- Internal Revenue Service, P.O. Box 409101, Ogden, UT 84409: a foreign country or U.S. territory
How do you fill out Form 1120?
Page 1 runs top to bottom. Income sits on lines 1a through 11, deductions on lines 12 through 27, and the result carries down to taxable income on line 30. Schedule J figures the tax at 21% of taxable income, subtracts credits, and totals payments. Schedule C handles dividends and special deductions. Schedule K asks other questions about ownership, accounting method, and what else you have to report. Schedules L, M-1, and M-2 cover the corporation's books.
Complete every applicable entry space. Do not enter "See Attached" or "Available Upon Request" in place of a figure. Attach schedules and other forms after page 6 in the order the instructions set out, beginning with Schedule N and Schedule D. Put the corporation's name and EIN on each supporting statement. An officer signs and dates the return. If total receipts and total assets at the end of the year are both less than $250,000, you can skip Schedules L, M-1, and M-2.
What changed on the 2025 Form 1120?
Two lines were added for section 1062, which lets a taxpayer elect to pay the tax on gain from selling qualified farmland property to qualified farmers in four equal annual installments. Report the full liability on Schedule J, line 22b, and the first installment on line 32. The election covers sales and exchanges in tax years beginning after July 4, 2025. Direct deposit fields are new at lines 37c, 37d, and 37e. The minimum late filing penalty rose to $525 for returns required to be filed in 2026.
Form 1120 line by line
| Line | What goes there |
|---|---|
| 1a | Gross receipts or sales from all business operations, except amounts that belong on lines 4 through 10. |
| 1b | Cash and credit refunds made to customers for returned merchandise, plus rebates and other allowances. |
| 2 | Cost of goods sold. Enter the amount from Form 1125-A, line 8, and attach that form. |
| 11 | Total income. Add lines 3 through 10. |
| 12 | Deductible officer compensation. If total receipts are $500,000 or more, attach Form 1125-E and use its line 4. |
| 19 | Charitable contributions paid within the tax year, plus unused amounts carried over from prior years. |
| 26 | Other deductions not listed elsewhere. Attach a statement listing each one by type and amount. |
| 27 | Total deductions. Add lines 12 through 26. |
| 29a | Net operating loss carryovers from other tax years, capped at taxable income after special deductions. |
| 30 | Taxable income. Subtract line 29c from line 28. This is the figure Schedule J multiplies by 21%. |
| 31 | Total tax, carried over from Schedule J, line 12. |
| 35 | Amount owed, when payments and credits on line 33 come to less than lines 31, 32, and 34 combined. |
| 36 | Overpayment, when line 33 is larger than the total of lines 31, 32, and 34. |
| 37b | The part of the overpayment you want refunded. Add bank details on lines 37c, 37d, and 37e for direct deposit. |
Penalties and withholding
5%
Of the unpaid tax for each month or part of a month a return is filed late
25%
Cap on the late filing penalty, with a separate 25% cap on the late payment penalty
$525
Minimum penalty for a return required in 2026 that is over 60 days late, or the tax due if smaller
1/2 of 1%
Of the unpaid tax for each month or part of a month the tax goes unpaid
Source: IRS, Form 1120 (Rev. 2025) and Instructions for Form 1120, U.S. Corporation Income Tax Return. This page explains the form in plain English. It is not tax advice.