Whatever type of business or professional activity you're involved in, you'll need to provide the IRS with a six-digit code that shows the nature of your business. This code is reflected at the top of the annual Schedule C or C-EZ for a sole proprietorship business, Form 1065 for a partnership, or Form 1120-S for an S corporation; or on the third page of the Form 1120 you file for a C corporation.
Use the code that applies to the majority of your business income and expenses. It is important that you use the correct code--the IRS will examine your return and determine whether your expenses are reasonable based upon your type of business.
If you can't figure out which business code applies to the majority of your business income and expenses, you might have two separate businesses and each one will require its own Schedule C or C-EZ
The file is in rich text format (RTF) that is suitable for use with most word processing programs used in the Windows environment.
For more information, see our discussion of identifying your business.