A personal trust expert believes the number of trusts will shrink under a re-write of the law which will spell out the exact responsibilities of trustees.
The Trusts Bill was introduced to parliament this month, four years after the Law Society made recommendations on updating New Zealand's Trustee Act 1956.
The government estimates there are somewhere between 300,000 and 500,000 trusts operating in New Zealand and New Zealand has one of the highest levels of trusts per head of population globally.
Richard Broad, head of legal personal client service at Perpetual Guardian, said the bill would spell out the exact responsibilities of trustees for the first time which may put a lot of people off becoming a trustee.
"I don't think many people understand what it is to become a trustee. The bill will make that clear."