A marriage certificate (proof of marriage) may be available for request after the marriage license (license to wed) is registered with the County Recorder. Our office only registers licenses issued in San Diego County.Appointments are available up to 7 weeks in advance and fill up quickly. An affidavit is a sworn statement of fact that can be used in a variety of legal proceedings, from bankruptcy cases to family and civil litigation matters. An affidavit is a written statement made under oath that is typically used in legal proceedings. Learn their purpose, when to use, and how to write. Your name must be entered exactly as it appears on the identification to be presented at time of issuance. Application For A Marriage Certificate (By Mail) Form. This is a California form and can be use in San Diego Local County. The certificate shall also contain the signatures of at least two of the witnesses present at the civil marriage who shall be at least 16 years of age.