Ease of use is where many databases fail. Some state sites have a search box that works fine. Others bury the information in PDFs or require you to know the exact business name. For instance, Texas has a public database for sales tax permits, but you might need the taxpayer number. If you're an operator, you likely have that number. But if you're researching a competitor, it's harder. Still, most official sites are workable. The key is to know where to look. Start with the state's revenue department, then health department, then attorney general's office.