California Code, Family Code - FAM § 300

(a) Marriage is a personal relation arising out of a civil contract between two persons, to which the consent of the parties capable of making that contract is necessary. Consent alone does not constitute marriage. Consent must be followed by the issuance of a license and solemnization as authorized by this division, except as provided by Section 425 and Part 4 (commencing with Section 500).

(b) For purposes of this part, the document issued by the county clerk is a marriage license until it is registered with the county recorder, at which time the license becomes a marriage certificate.