Postal ballot forms will start going out on Monday morning for the election to the Ngā Tāngata Tiaki o Whanganui trust.
There are 12 people nominated for four empty seats on the trust, the governance organisation handling the proceeds from the Whanganui River Treaty settlement.
Ngā Tāngata Tiaki was set up with a first intake of seven trustees, and a postal vote will decide who fills those seats from September.
Three of the replacements have already been chosen by the whole-of-river Te Runanga o Te Awa Tupua. They are Alaina Teki-Clark, current deputy chairman Rawiri Tinirau and Joey Allen, who will represent Taumarunui.
That leaves four places, and there are 12 nominees.
Standing for election are current chairman Gerrard Albert, current trustees Chris Kumeroa and Keria Ngakura Ponga, and Elise Te Hau Whakaheke Adams, Kiritahi Firmin, Hayden Potaka, Hannah Rainforth, Christopher Dudley Shenton, Esther Tinirau, settlement negotiator Nancy Tuaine, advisory trustee Tracey Waitokia and former Ngāti Rangi chief executive Che Wilson.
Two current trustees are not standing again. They are Miriama Cribb and Te Reneti (Ned) Tapa.
One of the original trustees, Susan Osborne, was removed from the board last year. The first seven trustees took office in September 2015. The next seven will also serve a three-year term.
People registered with the iwi can vote for four people to fill the other positions. They will be sent postal voting packs, starting on Monday and they will have until August 29 to vote.