Myths about inheritances may be deterring people from making a will, with a recent survey showing half of New Zealanders don't have a testament.

Wills and estate provider Public Trust commissioned the survey, which also found the South Island had more people with wills than the North Island.

Public Trust's managing solicitor Henry Stokes said misconceptions about inheritances could be stopping people from drafting a will.

One of the biggest myths was that if you die without having made a will, a person's entire estate automatically goes to the partner, he said.

"In fact, if someone with a partner and children dies, the first $155,000 of their assets and personal chattels will go to their partner.

"The partner then gets one third of the balance and the children two thirds," he said.

"But if there are no children and the deceased person has a surviving parent or parents, the partner gets two thirds of the balance and the parents one third."

Stokes said not leaving a will could lead to partners facing financial problems or estranged family members inheriting part of a person's estate.

The Public Trust survey also showed 66 per cent of 25 to 39 year olds don't have a will.

For people aged between 40 and 54, that number was 36 per cent, while the number falls to 12 per cent for those above the age of 55.

Public Trust's Alex Polascheck said drafting a will was "quite an emotional thing to do" and sometimes people found it too difficult.

Common concerns driving people to make a will included a dislike for a child's partner or fear they could make a claim on the inheritance.

"For people with young families the main focus is arrangements for the care of their children," he said.