They would try to tax our AZ construction projects whenever we ordered any material from CA, even though the addresses were always in AZ, you have to fight every single notice their automated system spit out, it was so annoying and I heard similar complaints from companies in several neighboring states like NV and OR, they don't even care that they are totally illegally trying to collect taxes, if you don't respond to their notices they start adding up penalties and interest on their bogus claims.