Employers are required to withhold California Personal Income Tax (PIT) from their employees' wages and report and pay the withheld taxes to the Franchise Tax Board (FTB) on a quarterly basis. The process involves calculating the PIT withholding based on the employee's tax filing status and allowances, submitting the quarterly returns (DE 4, DE 4A, or DE 4B) and paying the withheld taxes by the due dates.