Ordinary business income is the profit your business makes after you subtract your operating costs from your revenue

If you own a business — whether you're a sole proprietor, partner, or S-corporation shareholder — the money left after you pay for inventory, payroll, rent, utilities, and other expenses is ordinary business income. The IRS taxes this at your regular income tax rate, which varies based on your tax bracket. This is different from capital gains, which come from selling business assets like equipment or property.

The key word is ordinary. It means the income comes from the normal operations of your business, not from one-time events. A bakery's profit from selling bread is ordinary business income. The money a bakery makes from selling its building ten years later is not — that's a capital gain.

Ordinary business income flows through to your personal tax return, even if your business is a separate legal entity. You pay self-employment tax on it (Social Security and Medicare), plus regular income tax. This is why business owners often pay more total tax than employees earning the same amount — they cover both the employer and employee portions of FICA taxes.

Key Takeaways

  • Ordinary business income is what remains after you subtract all legitimate business expenses from your total business revenue.
  • The IRS taxes ordinary business income at your marginal income tax rate, not at a special lower rate like capital gains receive.
  • You owe self-employment tax (15.3% combined for Social Security and Medicare) on ordinary business income in addition to regular income tax.
  • Business structure matters: sole proprietors report it on Schedule C, partners on Schedule K-1, and S-corp shareholders on Schedule K-1 as well.
  • Ordinary business income is taxed every year you earn it, unlike capital gains which are taxed only when you sell an asset.

How ordinary business income differs from other income types

Ordinary business income sits in the middle of the tax hierarchy. At the bottom are tax-free items like municipal bond interest. Above that are long-term capital gains, which the federal government taxes at 0%, 15%, or 20% depending on your income level — lower than ordinary income rates for most people. Ordinary business income sits above that, taxed at your full marginal rate.

The difference matters because it changes how much you owe. Suppose you're in the 24% federal tax bracket and you earn $50,000 in ordinary business income. You owe $12,000 in federal income tax on that amount. If you had earned $50,000 in long-term capital gains instead, you might owe only $7,500 (at the 15% rate). You also owe self-employment tax on ordinary business income — roughly $7,065 on $50,000 — but not on capital gains.

may have access to dividends from stocks and bonds receive preferential treatment similar to capital gains. Wages from a job are taxed like ordinary business income, but your employer withholds taxes throughout the year, whereas business owners typically pay estimated taxes quarterly.

Which business structures report ordinary business income

Your business structure determines how ordinary business income reaches your tax return. A sole proprietor reports all business income and expenses on Schedule C (Form 1040), then transfers the profit to the main return. The income is taxed at your personal rate, and you owe self-employment tax on the full amount.

A partnership or S-corporation does not pay income tax itself. Instead, the business calculates its profit and issues a Schedule K-1 to each owner. You report your share of ordinary business income on your personal return, even if the business did not distribute cash to you. You still owe self-employment tax on partnership income, though S-corp shareholders can sometimes reduce this by taking a salary and a distribution.

A C-corporation is the exception. The corporation itself pays federal income tax on its profit at the flat 21% corporate rate. When the corporation distributes dividends to shareholders, those dividends are taxed again at the shareholder level — this is called double taxation. For this reason, most small businesses choose S-corp or partnership structure to avoid it.

A limited liability company (LLC) is not a tax structure by itself. An LLC can choose to be taxed as a sole proprietor (if single-member), partnership (if multi-member), S-corp, or C-corp. The choice determines how ordinary business income is reported and taxed.

What counts as a business expense and what does not

Ordinary business income is calculated by subtracting deductible business expenses from gross revenue. The IRS allows you to deduct costs that are ordinary and necessary for your business. This includes rent or mortgage on a business location, employee salaries, supplies, utilities, insurance, vehicle expenses, and professional fees.

Some expenses are partially deductible. If you use part of your home for business, you can deduct a portion of rent, utilities, and depreciation using the home office deduction. If you use a vehicle for both business and personal driving, you deduct only the business-use percentage. You can deduct either actual expenses or the standard mileage rate — in 2024, that was 67 cents per mile for business use — but not both.

Expenses that are not deductible include personal or family expenses, capital purchases (which are depreciated over time instead), fines or penalties, and lobbying costs. Meals and entertainment are only 50% deductible (with some exceptions for 2021–2025). Clothing is deductible only if it's specialized work clothing that you cannot wear elsewhere — a chef's uniform yes, business suits no.

The line between a business expense and a capital asset matters. If you buy a computer for $500, that's likely an expense you deduct in one year. If you buy a building for $500,000, that's a capital asset you depreciate over 39 years. The IRS has rules about when an expense is large enough to be capitalized instead of deducted when ready.

How self-employment tax applies to ordinary business income

When you work for an employer, your paycheck shows federal income tax withheld, plus 6.2% for Social Security and 1.45% for Medicare (FICA taxes). Your employer pays an equal amount on your behalf. When you earn ordinary business income, you pay both portions yourself — this is self-employment tax.

Self-employment tax is 15.3% total: 12.4% for Social Security (on income up to a cap, which was $168,600 in 2024) and 2.9% for Medicare (on all income, with an additional 0.9% Medicare tax on income above certain thresholds). You calculate it on Schedule SE and pay it when you file your return or through quarterly estimated tax payments.

You can deduct half of your self-employment tax as an adjustment to income on your return, which reduces your taxable income slightly. But you still owe the full amount. This is why business owners often pay more total tax than employees earning the same gross income — they cover both sides of FICA.

S-corp shareholders can reduce self-employment tax by splitting their income into a reasonable salary (which is subject to self-employment tax) and a distribution (which is not). This strategy only works if the salary is genuinely reasonable for the work performed — the IRS scrutinizes S-corps that pay themselves $20,000 salary and take $200,000 in distributions.

Quarterly estimated tax payments for business owners

Because no employer withholds taxes from business income, you're responsible for paying estimated taxes throughout the year. The IRS expects you to pay in four installments: April 15, June 15, September 15, and January 15 of the following year. You calculate estimated tax using Form 1040-ES.

Estimated tax includes federal income tax, self-employment tax, and any other tax you expect to owe. If you underpay, you may owe a penalty even if you ultimately get a refund when you file your return. If you overpay, the excess is credited to your next year's taxes or refunded.

The safest approach is to pay 100% of the prior year's tax liability in estimated payments (or 110% if your prior-year income was over $150,000). This generally protects you from penalties, even if your current year's income is higher. Many business owners set aside 25% to 30% of each month's profit to cover taxes, then adjust their estimated payments based on actual results.

Reporting ordinary business income on your tax return

How you report ordinary business income depends on your business structure. Sole proprietors use Schedule C to report gross income, deductible expenses, and the resulting profit. This profit is then transferred to Form 1040 and taxed at your personal rate. You also complete Schedule SE to calculate self-employment tax.

Partners and S-corp shareholders receive a Schedule K-1 from the business showing their share of ordinary business income (and losses, deductions, and credits). You report this on your personal return even if you did not receive a cash distribution. The business files Form 1065 (partnership) or Form 1120-S (S-corp) to report its total income and issue K-1s to owners.

C-corp shareholders do not report business income on their personal returns unless they receive a dividend. The corporation files Form 1120 and pays tax on its profit. Shareholders report only dividends received, which are taxed at capital gains rates.

Keep records of all income and expenses for at least three years. The IRS can audit back three years as a standard matter, and longer if they suspect underreporting. For business owners, good record-keeping is not optional — it's the difference between defending a deduction and losing it.

Frequently Asked Questions

Is ordinary business income the same as gross revenue?

No. Gross revenue is all the money your business takes in. Ordinary business income is what's left after you subtract operating expenses. If a consulting business brings in $100,000 in revenue and spends $30,000 on office rent, software, and supplies, ordinary business income is $70,000.

Do I owe self-employment tax on business losses?

No. Self-employment tax is calculated only on positive net income. If your business loses money in a year, you owe no self-employment tax. You can carry the loss forward to offset future years' income, which may reduce self-employment tax in those years.

Can I reduce ordinary business income by taking a salary in an S-corp?

Yes, but only if the salary is reasonable. An S-corp owner who takes a $20,000 salary and $180,000 distribution on $200,000 of income will face IRS scrutiny. The salary must reflect what you would pay someone else to do your job. A reasonable split might be 40% salary and 60% distribution, depending on the business type.

What happens if I don't pay estimated taxes?

You'll owe a penalty when you file your return, even if you ultimately get a refund. The penalty is calculated based on how much you underpaid and how late the payment was. Paying 100% of your prior year's tax liability in estimated payments generally avoids the penalty.

Is ordinary business income taxed differently at the state level?

State tax treatment varies widely. Some states tax ordinary business income at a flat rate, others use brackets like the federal system, and a few have no income tax at all. Some states also impose a separate business income tax or franchise tax. You'll need to check your state's rules when calculating total tax liability.