 A marriage certificate may be required for a number of reasons.It may be required as evidence of change of a party's name, on issues of legitimacy of a child, during divorce proceedings, or as part of a genealogical history, besides other purposes.Though marriage in Australia is regulated under federal law, the registration of marriages takes place under the respective state or territory laws, generally through an agency named "Registry of Births, Deaths and Marriages" or similar, and marriage certificates are issued by these agencies.