Under California Business and Professions Code section 16600, any agreement entered into with the purpose of limiting trade or business of any kind is to that extent void and unenforceable. California courts have consistently declared this provision an expression of public policy to ensure that citizens shall retain the right to purpose any lawful employment and enterprise of their choice. The interest of employees in their own mobility and economic prosperity are deemed paramount to the competitive business interests of employers as our society is built on and strongly encourages competition in trade and business.
This means that despite having agreed not to compete, a former employee has the right to enter into competition with his former employer, even for the business of those who had formerly been customers of the former employer. It makes no difference that the covenant not to compete is reasonably limited in time and geographic scope.
In one case, an employment agreement provided in part: “Employee will not render services, directly or indirectly, for a period of one year after separation of employment with Employer to any person or entity in connection with any “competing product.” This agreement was held to violate Bus. & Prof. C. section 16600 and was therefore found void and unenforceable.