1120 S Tax Form

The 1120 S Tax Form, also known as the U.S. Income Tax Return for an S Corporation, is a crucial document filed by S corporations in the United States to report their financial activities and determine their tax liability. The Internal Revenue Service (IRS) requires all S corporations to file this form annually, providing a detailed overview of their income, deductions, and other relevant financial information.

Key Features:

1. Purpose:

The main purpose of the 1120 S Tax Form is to calculate and report the taxable income of S corporations. S corporations, also referred to as S corps, are a popular business structure that combines the legal benefits of a corporation with the tax advantages of a partnership. By filing the 1120 S Tax Form, S corporations can pass their profits, losses, deductions, and credits through to their shareholders, who report them on their personal income tax returns.

2. Filing Requirements:

S corporations that meet the eligibility criteria must file the 1120 S Tax Form. To qualify, a corporation must be a domestic corporation, have only allowable shareholders (including individuals, certain trusts, and estates), have no more than 100 shareholders, and only have one class of stock. Moreover, all shareholders must consent to the S corporation election.

3. Information Required:

Within the 1120 S Tax Form, S corporations must provide a comprehensive picture of their financial activities, including their sources of income, deductions, credits, and any other relevant information. This includes details on sales revenue, cost of goods sold, salaries, wages, dividends, interest income, and other income sources. It also requires an itemized breakdown of expenses, such as rent, utilities, research and development costs, and employee benefits.

4. Schedule K-1:

A key component of the 1120 S Tax Form is Schedule K-1, which reports each shareholder’s share of the corporation’s items of income, deduction, credit, and other necessary information. S corporations must issue a Schedule K-1 to each shareholder annually. Shareholders then use this information to report their share of the S corporation’s income or loss on their individual tax returns.

5. Due Date and Penalties:

The 1120 S Tax Form must be filed by the 15th day of the third month after the close of the corporation’s tax year, which is usually March 15th for calendar year corporations. Late filing or failure to file the form can result in penalties imposed by the IRS. It is essential for S corporations to meet their filing obligations to avoid unnecessary penalties and potential audits.


In summary, the 1120 S Tax Form is a crucial document that S corporations use to report their financial activities and determine their tax liability. By providing detailed information on income, deductions, and credits, the form enables S corporations to pass their profits or losses through to shareholders, who report their share on their individual tax returns. Filing the 1120 S Tax Form accurately and on time is vital to ensure compliance with the IRS and avoid penalties.

This glossary is made for freelancers and owners of small businesses. If you are looking for exact definitions you can find them in accounting textbooks.

Invoice Template image

Invoice Templates

Our collection of invoice templates provides businesses with a wide array of customizable, professional-grade documents that cater to diverse industries, simplifying the invoicing process and enabling streamlined financial management.
Estimate Template image

Estimate Templates

Streamline your billing process with our comprehensive collection of customizable estimate templates tailored to fit the unique needs of businesses across all industries.
Receipt Template image

Receipt Templates

Boost your organization's financial record-keeping with our diverse assortment of professionally-designed receipt templates, perfect for businesses of any industry.