Get Answers Support Tax Filings & Payments State Filings General What is a state ID number? Last modified 1/12/2023 5:19:51 AM EST A state ID number (also known as a state EIN, a state employer ID, or a state tax registration) is a unique number assigned by the state to all the businesses or organizations operating in that state and is used for filing taxes. So, when declaring the income and withholdings for a state, the employer's State ID number is required. You can find this information in the letter you received from the state’s department of revenue while registering your business. Click here to learn more about the states that mandate state ID number Was this helpful? Yes No Related Questions Do you support W-2 filing for all states? How to fill in the state information in W-2? Does TaxBandits support 1099 filing for all states? Go to Home Page Need more help? Get in touch with our dedicated support team Contact Us (704) 684-4751 support@taxbandits.com Sign Up for a FREE TaxBandits Account! The Smart CPA Choice Register Now Already have an account? Sign in