(1) Where there is more than one competent authority for a designated person under section 60, those competent authorities may agree that one of them will act as the competent authority for that person, and references in this Part to a competent authority are to be construed accordingly.
(2) An agreement under this section, in relation to a designated person, takes effect when the competent authority who has agreed to act as the competent authority for the designated person gives notice, in writing, to that person.
(a) any of the parties to the agreement gives notice, in writing, to the other parties of the termination of the agreement,
(b) the agreement expires, or
whichever is the earliest.