Who must obtain a seller's permit? What does engaged in business mean?If you will be selling items at a location for less than 90 days, you are considered a temporary seller, and are required to hold a temporary seller's permit. The following links will help ensure businesses are properly licensed, and, if needed, registered with the state. Applying for a Business License. This tax does not all go to the state, though. If you are not registered for GST, make purchase order which will show all prices as GSTinclusive and make no mention of GST. This is the total of state, county and city sales tax rates. Businesses selling goods subject to the state sales tax must apply for a seller's permit with the State Board of Equalization. City agrees to purchase, and Vendor agrees to sell, will be shipped in separate boxes or containers for each destination, at no charge.