You will need to complete the application form and present valid identification. Acceptable forms of I.D. must provide photo and age verification.You can view the appointment calendar, schedule an appt. And complete your application online. Both parties must appear in person and bring valid picture identification to the County Clerk's Office to apply for a marriage license in California. California State Law requires: Applicants must be at least 18 years old. Both applicants must be present when applying for a marriage license. In order to get married in California, you will need a marriage license. You can obtain a license from any county clerk's office. Marriage licenses are complicated and often confused with a marriage certificate.