Moonlighting

Generally speaking, the answer is yes. There is no law in Washington that prohibits an employer from imposing restrictions on outside employment. But like most legal questions, the answer depends on all the facts and circumstances. It is possible that there could be an exception depending on the employer’s policies, whether you are in a labor union, and whether the specific outside activity might be protected by some other law.

Many employers list in their handbooks that outside employment is either prohibited or needs to be approved by the company before being undertaken by a current employer. There are various reasons for this, such as a potential conflict of business interest. Equally important is the fact that an outside job can effect an employee's performance: juggling two jobs can eventually impact one's performance in one or more of the jobs - as well as occupy one's time during work hours and limit the availability for overtime if required by your position. Absent express prior approval from the owner, supervisor or human resources, most companies do not permit moonlighting -- working a second job. Other employment, while not directly competitive with your first employer operations, may impact adversely on an employee’s ability to work. This could hold true for self-employment. Good luck.

As my colleagues stated, generally, an employer can prevent you from working a second job, but such restriction has to be explicitly stated in your employment contract and agreed to by you. If the restriction is only in an employee manual and not in a signed employment contract, the restriction may not be enforceable, but you will need to consult a qualified employment lawyer for a full review of your rights and responsibilities under your employment contract or employee handbook.