Changes to Council Directive of 19 December 1977 concerning mutual assistance by the competent authorities of the Member States in the field of direct taxation and taxation of insurance premiums (77/799/EEC)
EU Directive 1977/799
Made by Council Directive 2006/98/EC of 20 November 2006 adapting certain Directives in the field of taxation, by reason of the accession of Bulgaria and Romania
From legislation.gov.uk's record of changes, the official one: see it there.