can the social security number be used as us taxpayer identification number
The IRS website notes taxpayer identification numbers are used by the agency in the enforcement of tax rules and laws. A social security number can be used as one form of tax ID number. As a business owner you will probably need a tax ID number besides your social security number. A self-employed, sole proprietor with no other employees can file her business taxes using her social security number as a business tax identification number.