If you go into business as a sole proprietor, you may be able to use your Social Security number as your business tax ID. However, as soon as you take on employees, you are required to obtain federal and state tax identification numbers. Some states also require that you register your business' legal structure. Many require that you get a federal tax ID number before obtaining your state tax ID.

Register your business with the secretary of state's office for your state. Many state websites have pages targeted to small businesses, with links to the registration forms. Fill out the forms online or in print and submit them, along with any filing fee. Response time varies by state.

Obtain a federal tax ID number, also known as an employer identification number, if your business has employees. You can apply online at the Internal Revenue Service website. If you apply by phone at the IRS small business helpline, 1-800-829-4933, you'll receive your number at the end of the call.

Register your business with your state's revenue department or other tax authority. In many states, you can do this on the agency's website. Fill out the registration form online, or download it, complete it and mail it to the agency. Registration requires your business owner name, telephone number, mailing and physical addresses, and your organization's age and primary business. You might also need to provide your federal tax ID number and an email address.

Check the mail for your state tax registration packet. It will include your tax ID number and other information that might be helpful to a new business owner in your state.

Tip

Check with your state or local licensing authority for any licenses or permits needed to operate a business in your city or state.

In most states, unless you operate your business under your own name, you must file a "doing business as" statement with the state or your county clerk's office.