I would start by trying to look up the entity (or DBA) on your state's Secretary of State (or other business registry) website. You will typically be able to view assumed name certificates/doing business as (DBA) documents as well as articles of incorporation/organization - which will help you to understand the type of business you are dealing with. If it is a sole prop, as Randy said, the owner could have a separate tax ID for the business and a DBA, but it is still a sole prop. If it is another type of entity like an LLC, it could also have a DBA and do business in a different name. In fact, some business names/structures can seem quite complex on the surface.
The bottom line is that I would try to uncover the true entity type and then go from there. If you still have questions about the business structure, a CFO/CPA, a seasoned commercial lender or other seasoned banker may be able to assist with understanding it.
And welcome to BOL!
_________________________
Adam Witmer, CRCM
All statements are my opinion, not those of my employer, and should not be taken as legal advice.
www.compliancecohort.com