Corporate Taxes in the US [2026 Guide]

US businesses owners running a C Corp – and some LLCs – need to understand the Federal corporate tax rate and filing protocols. While some business entities like sole proprietors and partnerships pass through profits and losses to their owner’s personal income tax filing, other business types need to file separately.

The US corporate tax rate in 2026 is 21%.

This guide walks through how corporate income tax works, which entities need to pay, how to complete a corporate tax return and the corporate tax deadline you need to stick to.

Corporate income tax (CIT) in US overview

If you have a US business, knowing the small business corporate tax rate and how to file is essential. Fines and penalties apply if you fail to keep up to date with your obligations, so getting some professional help is common to keep everything running.

The information provided here is not intended as financial or personalized advice. Seek the help of a professional advisor for your specific financial needs.

The corporate tax system in US

Corporate taxes in the US are administered at a Federal level by the Internal Revenue Service – IRS. In addition there may be extra state level taxes which vary depending on the location your business is registered in and where you operate.

Since the enactment of the Tax Cuts and Jobs Act in 2017, US federal income tax has been managed on a territorial rather than a worldwide system. This is a hybrid system which allows US businesses to apply for certain credits and deductions on foreign earned income, with US tax often waived on overseas subsidiary income.

The corporate tax rate that applies to you depends on the entity type you have, any deductions or credits which may be available, and where your business is based.

This guide looks at key details to help with your corporate tax planning in the US – but it’s not a substitute for personal advice from a tax accountant familiar with your specific business.

Who is required to pay corporate taxes in the US?

Generally C Corps are required to pay corporate taxes in the US. In some cases LLCs may also need to pay US corporate tax.

The key is to know if your business entity type is considered a pass-through business or not. Pass-through businesses usually include sole-proprietorships, partnerships, and S corporations, and some kinds of LLC.

These businesses do not have to pay corporate tax in the US as profits are passed through to the owners who pay individual income taxes instead.

Headline corporate tax rate

Corporate Tax in the US is set at 21%. This has been the case since the Tax Cuts and Jobs Act in 2017 which lowered corporate taxes from 35% to a historic low of 21%.

Compared to other major countries, the Federal level taxes are on the low side, but once you combine average state level taxes as well, the US tax landscape looks relatively close to other major economies in the G7.

Statutory rate vs. effective tax rate

The US corporate tax statutory rate, as we’ve seen, is 21%. However, this isn’t necessarily the rate that US businesses will end up paying as there are also credits and deductions which may be applied that can reduce the overall tax burden a business may have.

The effective tax rate is the percentage tax a business ends up paying after any relevant credits and deductions are applied. This is calculated as follows:

Total tax paid/Total taxable income = Effective tax rate

Generally the effective tax rate will be lower than the statutory rate – but the exact number differs for different business types.

How Wise Business simplifies international business finances

• Support your audit trail: Download monthly statements, help provide a clean audit trail for Foreign Tax Credit (FTC) claims.
• Integrates with major accounting platforms: Wise Business accounts sync with Xero and QuickBooks
• BatchTransfer for withholding tax (WHT): If your company pays international vendors, Wise Business can process bulk payments for up to 1,000 recipients at once by uploading a single file.

How corporate income tax is calculated in the US

When it’s time to file your US corporate taxes you may find you need a qualified accountant or advisor to support you to make sure everything works smoothly. Here’s a headline look at how corporate income tax is calculated in the US to give you an idea.

Taxable income vs. accounting profit

As a business owner you’ll need to know your accounting profit (pre-tax income) so you know how your company is performing. However, you’ll need to take a further step to calculate the taxable income that you need to submit to the IRS and that you’ll have to pay corporate taxes on.

To calculate your taxable income you’ll need to take your headline accounting profit and deduct any allowable expenses.

Common deductible business expenses

The exact expenses which are allowable in any given situation can vary. It’ll depend on your business type and other factors. Here are a few commonly deductible expenses you might want to look into when calculating your tax liabilities:

• Start up costs: new companies may be able to make a one off deduction to a fixed limit, based on the initial costs of setting up their business
• Business operating costs: some costs like rent, repairs, maintenance and business insurance can be deducted
• Marketing: the costs of advertising your business and entertaining clients may be deductible depending on the details and methods
• Employee Remuneration: if you have a team you may be able to deduct the costs of salaries, as well as other associated employee costs like health insurance and paid time off
• Vehicle and travel expenses: if you or your team need to travel for work you could deduct some costs, with specific deductions for electric vehicles
• Legal and professional: certain additional unavoidable professional costs may also be deductible

Non-deductible items to watch for

The IRS allows “ordinary and necessary” business expenses to be deducted, but this does mean that there are other key costs which you can not deduct from your tax calculations.

Non-deductible items include anything for personal uses, commuting, fines or legal fees and political or lobbying expenses.

Capital allowances and depreciation

The IRS allows for some depreciation in the value of property you own for your business. When you buy something for your company – a piece of machinery for example – you can’t claim the capital expense, but you may be able to claim the depreciation in value as it gets older.

Depreciable property must be for business use only, and must be expected to last for one year or more. It can include:

• Machinery and equipment
• Buildings and property
• Vehicles
• Furniture

Depreciation rules are quite complex so seek advice if you think you can add this to your US corporate tax filing.

Losses: Carry-forward net operating loss (NOL)

If your US C Corp had a NOL you may be able to carry this forward into the next year’s tax filing. The total amount carried forward can not be more than the taxable income you want to offset it against. Get advice from your accountant to ensure you file correctly in the event of a net operating loss.

How to file your corporate tax return in US & 2026 deadlines

Usually corporate tax is paid in installments and then a final tax return filed at the end of the relevant year. Let’s take a closer look.

2026 corporate tax calendar & key deadlines

You can find all of the IRS links to tax calendars for 2026 online. Generally you’ll need to file your final return by the 15th day of the 4th month after the end of your company’s tax year. The main exception to this is if you have a fiscal tax year ending June 30th – in this case you need to file earlier than the 4th month.

Being late to file can mean paying a penalty so make sure you’re clear on when it’s needed for your specific business.

The fiscal year (FY) vs. calendar year

You can make your IRS tax filing based on your own business fiscal year or the calendar year.

• Calendar year – January 1st – December 31st
• Fiscal year – any 12 consecutive months, ending on any day including the last day of a month (aside from December)

Some business types are obliged to use calendar year for accounting, but others can select their own fiscal year. If you need to change dates you may require IRS permission before you do so.

Preliminary and estimated filings

Most corporate businesses in the US make estimated payments and then complete a full tax return at the end of their business tax year. This is normally a requirement if you think your annual tax payment will be over 500 USD.

If this is your approach, you’ll have to make your payments to the IRS by the 15th day of the 4th, 6th, 9th, and 12th months of your company’s tax year.

Required forms and documentation

The key form you need to complete to file your US corporate taxes is:

• 1120, U.S. Corporation Income Tax Return

Depending on your situation there may also be some other forms to complete such as 941, Employer’s Quarterly Federal Tax Return if you have employees.

When you complete these forms there will also be some supporting documents needed. For example, if you’re claiming deductions or credits you will need evidence that you are eligible for these deductions. Your accountant can help you prepare your paperwork to submit everything smoothly.

Paying your taxes from a foreign currency? Check out Wise Business for low cost currency conversion and fast, secure payments to the US and many other countries globally.

2026 digital reporting

Under the IRS E-file for business and self employed taxpayers program, you’ll usually need to complete your corporate tax return electronically. This is recommended for most businesses and mandatory for some which submit larger numbers of returns annually.

Services like Wise Business may be helpful when preparing your digital tax documents, with benefits like integrations with accounting software to help accurate digital reporting.

Corporate tax exemptions and incentives in US

There are some specific IRS credits and deductions for business which may help reduce your taxable income. Some deductions which apply to individual taxpayers may also apply.

Credits can include:

• Opportunities for businesses investing in green technology or building energy efficient homes
• Employer childcare credits and credits if you offer pensions for employees
• Opportunity zones credit based on where your business operates
• Fuel tax and clean vehicle credits

Deductions are also available which can include:

• Mileage deductions for travel
• Home office deductions
• Energy efficient building deductions

Corporate tax fines in the US

Corporate tax fines in the US exist to encourage people to file correctly and on time, and to pay their bills as soon as possible. Some penalties which may apply include:

• Late filing of return – 5% of unpaid tax for each month to a maximum of 25%
• Late payment of tax – 0.5% of unpaid tax for each month to a maximum of 25%

There are also penalties for deliberately filing incorrectly – which can include criminal penalties if you’re found to be trying to evade tax.

Corporate tax advice in the US

You can find lots of information which is aimed at small business owners in the US on the IRS website, which can be a good starting point if you’re not familiar with corporate taxes in the US. However, you’ll usually find that having a qualified accountant on hand is a good solution to help you learn more about US taxes and put your mind to rest that you’re keeping on top of all your duties and obligations.

How to find a qualified accountant

You can make out word of mouth recommendations for tax support and accountants, or you can check the IRS Directory for tax preparers. If you choose to use an accountant make sure you’re working with someone who is property licensed and familiar with your type of company entity in the US.

International tax considerations

To properly know your business tax obligations you’ll need to be very clear on your business’ tax residency and where all of your income originates from.

If you’re doing business across more than one country, you may be eligible for a US Foreign Tax Credit (FTC) to mitigate double taxation if you’ve already paid tax on income in a different country.

If your company owns 50% or more of a foreign business you may also need to understand Global Intangible Low-taxed Income (GILTI) tax which is 10.5% – 13.125% and intended to ensure US businesses which own assets including intellectual property overseas pay tax properly.

Get professional advice to support your tax filings if you’re running a more complex multinational business as your tax matters are likely to be complicated.

Useful resources

Note: Research credit may be available to some US registered businesses for certain qualified research credit expenses. Check the IRS website for more information.

Information last checked on 28th of January, 2026

• Internal Revenue Service – IRS – landing page for IRS with links
• Tax Policy Center – Corporate Tax in the US – tax rates and historical information
• 1120, U.S. Corporation Income Tax Return – most common corporate tax filing document
• 941, Employer’s Quarterly Federal Tax Return – additional filing to IRS if you have employees
• IRS Directory – good place to look for tax preparers
• PWC – explainer by tax consultancy on US corporate taxes
• IRS – links to all tax calendars 2026
• IRS C Corp – details and links regarding forming a C Corp and paying corporate taxes
• E-file for business and self employed taxpayers – IRS program
• Wise Business pricing