While the specific rules vary from state to state if you operate the business under any name that does not clearly include your legal name, you need to register the business name as a DBA (Doing Business As).
How you register will depend on the business legal structure you choose and the state you are in.If you incorporate or form a limited liability company, contact the Secretary of State office, corporations division in your state for information and verification that the name you want to use is available.
If you are registering the name as a partnership or sole proprietor the most common filing requirement is with your county records office.
However, some states require all businesses to register on a state level.To determine the filing requirements for your state go to your state website and check in their business section to find the specific registration requirements.
Another consideration, before you do a lot of filing, is to get on the Internet and do some searches to see if another business is using a name similar to the one you plan to use.While finding another business in another part of the country might not stop you from using a name, in this age of E-commerce it's wise to do some basic research before you start running the presses for business cards and letterhead.