Researching potential customers – where are they? When you are researching a company but notice they do not put their physical address on their website (suspect), go the state’s attorney general’s (AG) office corporation search engine and find the physical address they used when setting up and officially registering their business. Even if they move, they are normally required to keep this address current. Go to the state where they have their office, possibly not your state. All states have corporation search engines and require a physical address to be registered.