When Can An Employer Make Deductions From An Employee's Paycheck?

In California, the default law is that employers are not allowed to take any deductions from employees’ paychecks.  However, many exceptions exist.  Employers may withhold portions of employees’ wages when required by law.  Perhaps the best examples of that are for tax withholdings or wage garnishments under court orders like for child support or spousal support.  Employers may also make deductions when an employee expressly authorizes it in writing.  Examples of these authorized deductions would be for health insurance premiums or union membership dues. 

(See Link(s): Labor Code Section 224)