Artists are responsible for collecting and paying state and local sales tax. Austin is in Travis County. Sales tax rates vary from one municipality to the other and may change periodically, but are typically 8.25%. Please refer to this online sales tax calculator to find out the current tax rate. The festival address is 11410 Century Oaks Terrace, Austin, TX 78758.
Please refer to this document for more detailed information about Texas sales tax laws for festivals.
Paying Your Taxes
You have several options for paying your sales tax. See this page from the Texas State Comptroller for details.