Scheduling an appointment will eliminate wait time, as walk-ins may wait as long as 2 hours. The average appointment lasts approximately 30 minutes.You will need to complete the application form and present valid identification. Acceptable forms of I.D. must provide photo and age verification. 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. There must be at least one witness present at the marriage ceremony. Wondering how to get married in California? Use our expert-backed guide on wedding planning in California, complete with marriage license This license is valid for 90 days from the issue date and can be used anywhere within the State of California.