What is Form 1120-S, U.S. Return of an S-Corporation?

There are a few ways to identify how your business is set up:

• Did you file a Form 2553 with the IRS to turn a C-corp or LLC into an S-corp? If so, your business is set up as an S-corp. 
• Do you have a partnership agreement or operating agreement? If so, your business is set up as a Partnership.
• If you run the business as an LLC and you're the sole owner, you have a Sole Proprietorship.
• What did you select when you created your EIN? This will also tell you how the business is set up.

For more on how to define your business type, read What type of entity is my business.

Whether you need to file your business and personal taxes together or separately depends on your business structure. Some situations may vary, but generally:

• Sole proprietorships, or income from an LLC that you are the sole owner of, may be reported on your personal tax return.
• C corporations, S corporations and partnerships must file a separate business tax return.

When filling your taxes within Turbo Tax, you'll be presented with questions that will help determine the type of business you have and how you should file.

To better understand requirements for your business, read Should I file my business and personal taxes together.

Shareholders of S-Corporations are liable for the tax on their shares of the corporation's income, and will report that income on their individual tax returns from Schedule K-1. Unlike other pass-through entities, S-Corporation income isn't considered self-employment income and isn't subject to self-employment tax. Your Schedule K-1 will be generated when the S-Corporation Form 1120-S return is prepared.