Sole proprietors sometimes set up trade names -- also known as DBAs (doing business as) -- so their company or a division of a company can do business under a separate name. Business attorney Nina Kaufman says there are a several factors to consider before setting up a DBA. For instance, if it's to set up a second line of business under a current company, you might want to develop a plan for managing financials for the individual operations, as that can become complicated, she says.