The Member States 25 March 1957, Consolidated version of the Treaty establishing the European Atomic Energy Community#TITLE V - General provisions#Article 202

(d) this Treaty shall apply to the Channel Islands and the Isle of Man only to the extent necessary to ensure the implementation of the arrangements for those islands set out in the Treaty concerning the accession of new Member States to the European Economic Community and to the European Atomic Energy Community signed on 22 January 1972.