California Commissioned Employees Must Have a Written Employment Contract
Effective January 1, 2013, every employee in California who is compensated, entirely or partially, by commission must have a written employment contract that states the method by which commissions will be computed and paid.
Labor Code Section 2571(a) says:
By January 1, 2013, whenever an employer enters into a contract of employment with an employee for services to be rendered within this state and the contemplated method of payment of the employee involves commissions, the contract shall be in writing and shall set forth the method by which the commissions shall be computed and paid.