How do I know if a company is registered or not? -

I am trying to do business with a US marketing firm. They tell me they are a registered incorporated business but I can t find them on BBB. So I want to see how I can check whether or not the are really registered businesses.

Go to the secretary of state s website in the state where they are allegedly located. BBB is not a good source of reliable information. Just because they are registered doesn t mean they are legitimate