You can set up a family trust before you die and just leave them inactive until your death. In your will you then leave assets to this trust and it can begin to operate. You can register an inactive trust with the IRD, and you would return a nil income in your IRD tax return. However, you need to notify the IRD again when the trust becomes active.

You can click on the links below to find out more:

IRD: Declare a trust or estate non-active

Non-active trusts and compliance