Mark Gouldstone, sustainability management specialist at BSI, said: "Jack Morton has implemented a best practice framework that demonstrates its commitment to making client events and experiences as sustainable as possible.
"Jack Morton and its employees should be proud of the hard work and commitment that has gone into implementing and achieving ISO certification."
Julian Pullan, Jack Morton Worldwide president, EMEA, added: "We are delighted that our work to improve sustainability has been recognised at this level. We’re committed to making a positive difference in the world in which we live and work and to helping our clients to achieve this through the innovative brand experiences we create with them.
"As members of the global community, we can only do this effectively if we do so sustainably and the ISO 20121 is great recognition of our commitment to do so."