The Purpose of Tax Identification Numbers

Tax identification numbers are used by federal, state, and local tax authorities to identify tax reporting entities such as individuals, businesses, nonprofit organizations, and trusts and to facilitate tax administration.

An individual's tax identification number is his social security number.

Tax Identification Numbers for Businesses

Here are the most common tax identification numbers used by businesses:

Sole Proprietors

If you're a sole proprietor, you need an Employer Identification Number (EIN) if any of the following apply:

Other reasons an EIN may be required:

File your personal and small business taxes (Schedule C)