A tax exempt number is an identification number issued to you by the state where your business operates. You present this number to suppliers when you purchase wholesale goods, enabling you to avoid sales tax charges. The sale of any item should only be taxed once, that is, when it is purchased by the end user. If you are buying a product that you will sell again during the course of operating your business or if you are buying materials that you will use for the purpose of creating a product that you will ultimately sell to an end user, you are exempt from paying sales tax on these materials.

Find the website for your state's department of revenue and click on the option that allows you to look up a business. The identifying information for your business is part of the public record and it is available to anyone who wants to find it.

Choose the option that enables you to search by the business name or the owner's name. Enter your name or the name of your business. If you cannot remember whether you registered your business using your own name or your business name, conduct your search in multiple ways, selecting the option that allows you to search for a name that includes a particular word or a certain first or last name.

Click "Search" to find names of businesses and business owners that match the names you have entered. Select the one for your own business. This will take you to a screen that shows your business information, including your tax exempt number.