Sales Tax Exemption

Regarding Sales Tax Exemption
If a U.S. customer is buying on behalf of an organization that is exempt from paying state and local sales taxes, FastSpring can refund the sales tax after the purchase has been completed.

More information here

From the time our support team receives a ticket with a tax refund request, it should take no more than 24-48 hours (and probably less) until the refund has been processed and we send a reply to the customer. After that, it can take a few business days for the funds to post back to the customer's payment account.