[Exhibitman]

There is no statewide business license in CA. Individual cities and/or counties have business license requirements and tax structures. Los Angeles, for example, has a gross receipts tax for many trades and businesses, which sucks ass big-time since you owe taxes even if you lose money on the whole, and forces many of us to locate our businesses in Burbank, Pasadena, or a number of other municipalities that collect only a flat rate tax for the year. My business in Burbank gets hit up for about $100 a year in business license fees, but my sole year in L.A., virtually the same gross receipts, cost me over two grand. It is a damned protection racket. The L.A. business license auditor popped into my office when it was in Hollywood and all but said "I smell smoke; pay up." Moved to Burbank as soon as my lease expired. But I digress...

As for the OP, sales tax is either collected on the purchase by the seller or you are required to declare the purchase and pay your state's use tax, which is the functional equivalent of a sales tax. In CA it is paid on the same tax return form as your sales tax if you have a resale permit, or on your state income tax return. However, every state has different rules. It is an administrative nightmare if you have a business in multiple states.

What has caused confusion as far as internet sales is that the internet companies and big players in internet sales [like Amazon] have fought tooth and nail to try and prevent the states from forcing them to collect and remit sales taxes. The laws are also riddled with exceptions to tax requirements, like food, which is not taxed in CA.