Doing Business under a Fictitious Name

This article from about.com describes some of the pros and cons of doing business under an assumed name in the UK. The principles are applicable as well in the US. The article states the basics as follows:

"An assumed name, alson known as ficitious business name, or DBA (short for 'doing business as'), or 'trading as' in the UK, allows you to legally do business as a particular name at minimal cost, and without having to create an entirely new business entity. You can accept payments, advertise, and otherwise present yourself under that name. In fact, if you present your business under a name other than your proper legal name without proper notification, it may be considered fraud. Fortunately, filing for an assumed name is so easy and inexpensive, there's really not much excuse for not filing one."