The employer identification number or (EIN) is obtained through the Internal Revenue Services. This number is used as a federal taxpayer identification number. You must apply for an EIN to do business in the State of Nevada, this includes Sole Proprietors if they pay wages to one or more employees or file any excise tax returns. You may contact the Internal Revenue Service at: 1-800-829-4933 or visit their Web site at www.irs.gov/smallbiz