29. Before the parties to a convertible Northern Ireland marriage can convert their marriage into a civil partnership under this Part, they must—
(a)attend together in person before the authorised person,
(b)give the authorised person the details required to complete the conversion declaration,
(c)provide a document issued under Article 35(3)(b) of the Marriage (Northern Ireland) Order 2003 relating to the registration of their marriage, and
(d)provide such evidence as may be required by the authorised person to satisfy the authorised person of the details provided in the conversion declaration.