If your eBay business operates under a fictitious name (often called a “DBA,” for “doing business as”), you probably have to register that name with your state or county government. A fictitious name does not refer only to a completely made up moniker, such as Xerox or Kodak. Any name that doesn’t precisely match your corporate, partnership, or limited liability company name is considered fictitious. If you are operating as a sole proprietor, any name that doesn’t include your last name (or, in some states, your full legal name) or seems to suggest that other people are involved in your business (such as John Brown & Associates) is fictitious.
In most places, DBAs are registered with your county government. Registration typically requires filing a registration certificate (along with a fee, of course) with the county. You may also have to run a statement in a local newspaper for a set period of time, stating your DBA and your true name.
The state wants you to register your name so it can track you down if your business does something wrong, such as ripping off consumers or skipping out on loans or bills. But there’s plenty in it for you, too. For starters, registering a DBA puts other companies on notice that the name is taken — and stakes your claim to use the name as of the registration date. Registering a DBA does not provide trademark protection, however. Read Registering Your Business Name to understand the difference.
There are other practical reasons to register a name. For example, some banks require a registration certificate in order to open a business bank account under a business's fictitious name. And you may not be able to enforce a contract you signed in the name of the business unless you can show that the name was registered properly.
Finding the forms. For information on registering a fictitious name, go to your county clerk’s website (you can probably find a link to it at State and Local Government on the Net). If the information you need is not there, check your state’s website.