By the third meeting in 2002 it became clear that a more formal body was needed both to represent the private landowner working in conservation at a local and regional level, and as a central body for resources. The need for a collective focus and goal was also required but the form of organisation could not be agreed upon.

In August 2002 there was a meeting with the Auckland Regional Council, Auckland City Council, the Department of Conservation, and Auckland University to bring forward for feedback the notion of a rat and feral cat free Great Barrier. There was a very positive response to this idea and it became clearer that a Trust-like body made up of local people was going to be needed to spearhead an investigation into the feasibility of this idea.

Following this meeting, it was decided to form the Great Barrier Island Charitable Trust and the formal aspects of establishing it were then undertaken. By 2003 the Trust was formed with locals John Ogden, Judy Gilbert, David Speir, and Tony Bouzaid as Trustees. The Trust has a broad conservation basis but an initial focus of eradicating rats and feral cats from the island.

At this time the Trust has a paid part time secretary, Fenella Christian and meets regularly, has begun raising funds for its activities, and is close to initiating a feasibility study for the eradication of rats and cats from the island.