There are a few legal requirements for a civil wedding ceremony. The most common requirement is that the couple must be 18 years old or older. There are other requirements, such as having witnessed and signing the marriage license (which is usually done at the courthouse). The legal requirements of a civil wedding ceremony vary depending on whether or not it is a religious wedding ceremony. A religious wedding ceremony requires that both parties be baptized members of the same religion, and they can only marry if they both sign an affidavit declaring this fact.