Employers can require employees to use a personal vehicle for work. Mileage reimbursement in California is meant to cover all costs of owning and operating a personal vehicle for the business portion of its use.The use of privately-owned automobiles for approved work is permissible provided it is done during the course of the employee's scheduled hours of work. It is lawful for your employer to make you use your own vehicle to drive to various locations for your job. You are entitled to be reimbursed all expenses you incur to do your job. California Mileage Reimbursement Law requires employers to reimburse employees for all vehicle expenses incurred on the job. Any employee who is requested to use their own personal vehicle for company purposes must have full compensation for fuel, oil and maintenance. A comprehensive guide to travel time pay rules in California—when employees are entitled to be paid for travel time and how to recover those lost wages. A comprehensive guide to travel time pay rules in California—when employees are entitled to be paid for travel time and how to recover those lost wages. Reimbursement if you use your personal car for work.