Summary
Businesses operating in the United States need to obtain an Employer Identification Number (EIN) or Federal Tax Identification Number (TIN) from the Internal Revenue Service (IRS) for the purpose of identification. Sole proprietors may choose to use their Social Security Number in place of a state EIN, but only if they operate in states that do not collect personal income tax.
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An EIN should not be used for any other purpose than tax administration.
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According to