If you follow the traditional tax calendar, you’re about to close your books on the year. Then, you have until April to file taxes for your company. That doesn’t mean you should wait until the spring thaw to start thinking about this critical to-do, though. Some planning in advance makes tax filing much easier.
With that in mind, we want to put the spotlight on the key piece of paperwork most companies need to submit to the IRS: Form 1120. Once you’ve founded a corporation, this becomes an annual requirement (yes, even if your company isn’t making any money yet).
Form 1120 is basically the corporate counterpart to your personal Form 1040, so it’s worth getting to know.
No income tax liability? No getting away from this form
There’s a general but stringent rule here: if you’re a domestic corporation, you’re required to file an income tax return. For most corporations, that takes the form of Form 1120.
The only workaround is if you file a special return (e.g., S-corps file an 1120-S, nonprofits file Form 990) or if you dissolve your company (even then, you still need to file a final return).
Notice that we didn’t say anything about a tax bill there. Even if your company hasn’t earned a single dollar or operates at a loss — and consequently won’t owe the IRS anything — you’re still required to file Form 1120 annually. The IRS even requires fully inactive companies to file.
If you have an ownership stake in a corporation that operates in the U.S., then, the IRS demands this form of you.
If you elect to file as an S-corp, you’ll use the tweaked version that is Form 1120-S. For the purposes of this overview, we’re focusing on the standard 1120. Even if you file as an S-corp, though, this should give you a good idea of what the IRS requires of your annual filing.
What goes into your Form 1120: Breaking down the schedules
The first page of Form 1120 serves as the centralized spot for all of your income tax reporting. It gathers up all of your income (e.g., gross receipts, dividends, capital gains) and deductions (e.g., salaries, depreciation, charitable contributions).
Then, the form gets into different schedules. To help you understand what corporate income tax filing requires at the federal level, let’s look at each of them.
It might seem like we’re skipping schedules here, but we’re not. (Take a look at the form to confirm.) Form 1120 doesn’t include Schedule A, for example, because corporations don’t take itemized deductions the same way individuals do.
Now that we’ve cleared that up, let’s look at the schedules Form 1120 does include.
Schedule C
This schedule highlights your dividends, inclusions, and special deductions. Most early-stage companies don’t use this schedule.
Schedule J
This schedule’s always required because it reports your corporate tax liability. Going line by line through this schedule allows you (or, ideally, your accountant) to apply things like your tax credits and estimated tax payments. The end result is the total you owe.
Schedule K
Titled “Other Information,” this schedule covers quite a bit of ground. It’s where you report your accounting method, shareholder details, and a series of required Yes/No questions that disclose important changes to your company. For example, were there 1099s issued? Did the corporation have an 80% or more change in ownership? Are there foreign shareholders owning more than 25% of the company?
There are additional questions in this section that are important to review before filing.
Schedule L
Here’s where you put your balance sheet, reporting your assets and liabilities to the IRS.
If your company has less than $250,000 in receipts and under $250,000 in assets, you’re technically exempt from this section. Still, your company should have all of this information handy to manage its own financial standing. As a result, it shouldn’t be hard for your accountant to complete.
Schedule M-1
This is where you reconcile the net income/loss reported on your financial statements (“book income”) with the income/loss reported for tax purposes (“taxable income”). Because tech companies tend to have pretty big timing differences here, this schedule’s important.
Schedule M-2
Technically called the analysis of unappropriated retained earnings, this schedule gives the IRS a look at how your owner equity has changed through the year. If you’ve issued dividends or accumulated deficits, you’ll report that here.
Forms to accompany your income tax filing
Most corporations attach additional external schedules to Form 1120 in order to satisfy the IRS’s reporting requirements. Some common ones for our clients include:
Form 6765 (the R&D tax credit form)
If your company plans to claim a credit for its qualifying research expenses (which, by the way, you probably should), you’ll use this form. New changes have made it more involved to complete. But because the R&D tax credit offers significant savings, it’s worth it.
Even if your company’s pre-profit, the R&D tax credit can reduce your bill for your employees’ Social Security and Medicare taxes by up to $500,000.
To claim this credit, you’ll also need to file Form 3800, the General Business Credit form.
You report your credit total in Schedule J on Form 1120, line 5c.
Form 1125-E (officer compensation)
This form breaks down what you’re paying your officers (likely including yourself) and how much ownership, if any, those people have. Your accountant can work with you to make sure you’re not under or overpaying here, which can raise a red flag for the IRS.
Form 4562 (depreciation and amortization)
If your company depreciates equipment or amortizes software development costs, you’ll need to add this form to your annual filing. Since the One Big Beautiful Bill Act restored 100% bonus depreciation, more companies will likely complete this form this year.
What you need to know to file
The IRS requires corporations to file Form 1120 by the 15th day of the fourth month after the end of the company’s tax year. If you follow the calendar year, that means your filing is due Wednesday, April 15, 2026.
You have time, but you don’t want to be rushing to get all the information you need together. Meet with our team of accounts now for a low-stress filing season this spring. Schedule some time with us at your convenience.
Get ahead of what’s coming and download our 2026 tax guide for a clear view of the rules, deadlines, and planning opportunities.
Disclaimer:
The content provided on this blog is for general informational purposes only and does not constitute professional accounting, tax, or legal advice. Reading or accessing this material does not create a CPA-client relationship, nor should it be construed as a substitute for individualized guidance from a qualified professional. While we strive for accuracy, Shay CPA PC makes no warranties—express or implied—about the completeness, reliability, or timeliness of the information, and we expressly disclaim liability for any errors or omissions. You should not act or refrain from acting based on any blog content without seeking the advice of a qualified CPA or other professional who can address your specific circumstances. Links to external resources are provided for convenience only and do not imply endorsement. Shay CPA PC is under no obligation to update this content and disclaims responsibility for decisions made in reliance on it.