Details are being confirmed, but the cathedral is working with Auckland's South African community to organise the service.
From next week there will also be a public memorial book in St Mary's Church next door to the cathedral.
South African-born radio presenter Irvin Adams says there has been a huge outpouring of emotion from expatriates.
"I think it's a huge shock for the community that his (life) has finally come to an end. But obviously his memory will continue."
Hundreds of people have left condolence messages in the memorial books at Te Papa.
International guests from Spain, Africa, the United States and Germany had all left comments, as well as local visitors, a Te Papa spokeswoman said.
Many of the comments simply said "Thank you" or "Rest in peace".
One of the memorial spaces screened footage of Mandela's only trip to New Zealand, in 1995, while he was President of South Africa.
People had been patient when it was apparent others needed a moment to gather their thoughts before leaving a message, she said.
A spokeswoman for Prime Minister John Key said travel plans hadn't been finalised but he would be taking a commercial flight to South Africa for Saturday's funeral, which is expected to be attended by most world leaders.
Former Prime Minister Jim Bolger said he would also attend the funeral. He was Mandela's host in 1995, during the Commonwealth Heads of Government summit.
A new movie about the South African's life, Mandela: Long Walk to Freedom, is due to screen in New Zealand from January. Distributors Roadshow said it was too soon to say whether there would be any special tributes at screenings.
