From 1977 to 1981, Macey was New Zealand's deputy permanent delegate to UNESCO in Paris. In 1985, he was appointed Official Secretary to the Government of Tokelau.
In 1987, he became Counsellor (economic) and Consul-General at New Zealand's embassy in Geneva, where he was a New Zealand negotiator in the Uruguay Round for dispute settlement. Apart from Macey's WTO responsibilities, he also represented New Zealand at the International Labour Organization.