Corporations are required to pay federal, state, and in some cases, local taxes. Most businesses must register with the IRS and state and local revenue agencies, and receive a tax ID number or permit.
When you form a corporation, you create a separate tax-paying entity. Regular corporations are called “C corporations” because Subchapter C of Chapter 1 of the Internal Revenue Code is where you find general tax rules affecting corporations and their shareholders.
Unlike sole proprietors and partnerships, corporations pay income tax on their profits. In some cases, corporations are taxed twice – first, when the company makes a profit, and again when dividends are paid to shareholders on their personal tax returns. Corporations use IRS Form 1120 or 1120-A, U.S. Corporation Income Tax Return to report revenue to the federal government.
Shareholders who are also employees pay income tax on their wages. The corporation and the employee each pay one half of the Social Security and Medicare taxes, but this is usually a deductible business expense.
Read more about tax requirements for Corporations on IRS.gov.