Your business may require a vendor license to make sales in the state of California. Visit California State Board of Equalization to obtain a temporary seller’s permit.
If your business does require that you obtain a temporary sellers permit for the state in which you are exhibiting, you also need to submit payment of sales tax after the conventions. Sales and use tax forms can be found at the website mentioned above.
Questions about taxes or licenses should be directed to the professionals at each state department.
Every person who engages in business in this state as a retailer must obtain a retail license before making any sales. This includes sales made online and persons who make infrequent sales in this state. If you have more than one business outlet, you must have a separate retail license for each location.