A DBA is recommended for any limited liability company that wants to do business under a name that is not its legal name. A DBA is common when an LLC is formed under someone's personal name and wants to operate the LLC under a business name, but there are a number of other reasons why a business owner might file a DBA. Many states have penalties for any registered business that operates under an unapproved fictitious name, so it's a good idea to file for one no matter where you do business. A DBA does not establish a new legal entity.