Guardian Trust was formed by a special Act of Parliament, the New Zealand Guardian Trust Company Act 1982, that merged the trust operations of South British Guardian Trust, formed in 1882, with the NZI Trust Department, authorised as a trustee company in 1916. The primary operation of these companies was as trustee, acting for their clients in the growth and protection of their wealth. This continues to be the core competency of Guardian Trust today.
Guardian Trust is now wholly-owned by The Trust Company, an Australian independent trustee services group listed on the Australian Securities Exchange. The combined group has total funds under supervision of approximately NZ$210 billion, and employs 440 people in 20 offices across New Zealand, Australia and Singapore.