A state employer identification number, also called an EIN, is an identification number businesses need to collect and pay state income tax. Only businesses that operate in states that do not collect personal income tax and sole proprietors that choose to use their Social Security number in place of a state EIN are exempt from holding a state EIN. You need your employer’s state EIN number to file yearly income taxes or to contact the Internal Revenue Service with questions you may have regarding income tax withholding
Look on line 15 of the W-2 form you receive by the end of January each year. The EIN number is a nine-digit number that follows the format XX-XXXXXXX.
Call your employer's human resource or accounting department and ask a representative to look up the information for you.
Contact the Department of Revenue for the state in which you live. Visit GovSpot.com to locate contact information for the Department of Revenue in your state if you already have this information. Contact the department by phone or by e-mail, if this is an option, and provide your employer’s legal business name and any other required information.