For the Vasiljevski siblings, a dispute after death prompts calls for laws to be changed.
David Vasiljevski was a young working man in his twenties when his parents told him that when they passed away everything they owned will belong to him.
When he and his wife looked at the will years later to find they kept their promise, it was an emotion-filled moment.
"When we opened the will and my parents' wishes were fulfilled that was a good moment for us in one way but it was pretty sad in another because I had just lost my mother."
This plan however, meant that nothing was left to Vasiljevski's older sister.
David says it was part of a family agreement made in the 1980’s, that would leave his sister out of his parents will, because she was gifted $25,000 to buy a house.
“Another part of the deal was I made arrangements with my father was that I had to take care of my mother until the day she passed and for the last 11 years and mainly the last 3 years, I came to the house every day to make sure everything was taken care of.”
"We were disappointed that the loyalty and the trust was betrayed by my sister."
The estate included the family home in the Sydney suburb of Newtown, which Vasiljevski and his wife have inherited. But his sister chose to take legal action a year after the contents of the will came to light.
“When we received the letter from her solicitors first of all we were very disappointed, the family and myself, because we felt the agreement was made and she was going to go through with it and we were disappointed that the loyalty and the trust was betrayed by my sister.”
Vasiljevski's sister contested the will successfully, winning a sum of money from the estate. David says Family Provision laws that allow a will to be changed are unfair and need to be reviewed.
“We need to make sure that people’s wishes, people who die and haven’t got a voice, that their wishes are fulfilled. It’s not fair for them because they’re not here to defend themselves.”
A new study by the University of Queensland has found his story is not uncommon.
Public Trust Office files showed that 74% of claims on wills are successfully changed through agreements or mediation. Of the contested wills that end up in court, 77% are successfully changed.
And it’s not just cases where people are left out of wills.
Diedre Lampard’s brother contested their mother’s will, where everyone was left an equal share.
"We were appalled because to us, it was never about the money, it was mum's wishes being challenged and you could not have got a fairer person than our mother."
This has prompted questions around how watertight our wills actually are and what can be done to ensure it is our last word.
Imelda Dodds from the NSW Trustee and Guardian sees cases like this all the time.
“Look, I’m not a lawyer, but I don’t know a lawyer or succession lawyer who says that it’s absolutely possible to write a watertight will.”
But succession law professor at the University of New South Wales, Prue Vines says we shouldn’t panic.
"The vast majority of wills don't get challenged and the person's wishes are followed through."
But that doesn’t provide much comfort for the Vasiljevski, who say their family has been torn apart because of the laws that allow wills to be challenged.
“We’re a small family, and I love my sister dearly, and at the moment I’m very disappointed at the law and that the trust was broken," he said.
In this episode, Insight discusses how wills can be changed after death and if it’s possible to make yours watertight.
Catch Insight at 8.30PM on Tuesday on SBS or live stream at www.sbs.com.au/insight/live