Any sales tax exemptions your nonprofit receives will depend on the states where you do business and the type of transaction involved. The process for requesting exemption from state sales tax varies widely. For example, in North Carolina, charitable organizations must pay sales tax but can file semiannually for a refund of sales taxes paid. But in Alaska, Delaware, Montana, New Hampshire, and Oregon, filing for exemption is not necessary as there is no state sales tax (although Alaska does have local sales tax).
In many states, you’ll have to fill out an application form and provide some supporting documents, such as an IRS determination letter and forms, financial statements, and a Form 990. In some cases, a 501(c) designation isn’t enough for a nonprofit to be exempt from paying sales tax at all.
Something else to note: Nearly every state provides exemptions to organizations making purchases of items intended for resale to an ultimate consumer. To find out if it’s possible to receive a sales tax exemption for your nonprofit in your state, you can use this IRS search tool or check your state’s department of revenue site. Washington’s can be found here.