Registering your fictitious business name is important for a number of reasons. Banks look for proof that you have properly registered the name when opening a business account. An even more important consideration is that you won't be able to enforce any contract that you sign under an unregistered name. An unregistered business name also leaves that name open for use by other businesses, even your competitors, which may jeopardize your business. Some states require that the fictitious business name be registered with the Secretary of State or other state agency.
Procedures vary, but the process is fairly easy.
In most states, you'll register it at the county level. Be sure to call your county clerk's office to find out its procedures, requirements and fees. Los Angeles county, for example, requires that the fictitious name be announced in a newspaper publication ad and that the applicant submit proof of publication, resulting in a longer processing time of about three weeks. On the other hand, Fairfax County in Virginia checks your fictitious name when you register your business and completes the process in less than 30 minutes. Sole proprietorships that need to pay federal excise of employment taxes are required to get an EIN Sole proprietors with no employees are not required to get an EIN, and can instead use their Social Security numbers.