The Talent Agencies Act in the California Labor Code defines a talent agency as "a person or corporation who engages in the occupation of procuring, offering, promising, or attempting to procure employment or engagements for an artist or artists."
"Artists" is defined as "actors and actresses rendering services on the legitimate stage and in the production of motion pictures, radio artists, musical artists, musical organizations, directors of legitimate stage, motion picture and radio productions, musical directors, writers, cinematographers, composers, lyricists, arrangers, models, and other artists and persons rendering professional services in motion picture, theatrical, radio, television and other entertainment enterprises."
In the state of California, anyone acting as a talent agent must be licensed by the State Labor Commissioner and is subject to state regulations, including office inspections and the required submission of records to the state.
Legally, a talent manager is not allowed to procure work for their clients; this is the agent's territory. In reality, the lines between agent and manager are often blurred in Hollywood, but it is important to understand the differences between the two professions.
The manager's job is to advise and counsel the artist, not to find employment.
Other states have similar laws, but the Talent Agencies Act developed in California because it is one of the film/television/music capitals of the world, and there was a concern over the welfare of artists.
The law dates from the 1913 Private Employment Agencies Law, which covered the "regulation of theatrical employment agencies and theatrical contracts." The law went through several amendments and became part of the California Labor Code in 1937.
The biggest changes came in 1959 when the now-dubbed "Artists' Managers Act" got its own separate chapter of the Labor Code, thanks to the growing awareness that the "business of procuring employment in the entertainment industry [. . .] is different [. . .] and more complex than the business of normal employment agencies." Eventually confusion over the division between agents and personal managers evolved into the "Talent Agencies Act" in 1978.
Besides contacting the California Labor Commission, the best way to verify an agent's standing is to contact the Screen Actor's Guild (SAG) or Association of Talent Agents (ATA).
Both of these groups offer agent searches on their websites, and most agents of high-standing are associated with one or both organizations.
Unlike agents, managers are not subject to any state regulation or licensing, which means that anyone can work as and call herself a manager.
That doesn't mean there aren't many good managers out there, but be sure to do your research. What's the manager's background? Does he come from a major talent agency or management company? How long has he been in business? Look at the client list--any recognizable names? Are their clients actually working?