Many people's wills are out of date, meaning their estates may not go to those they intend, it has been claimed.
According to figures produced by Unbiased.co.uk, 23 per cent of people have not updated such legal documents since buying or selling a property, while a third have not made any amendments within the last five years.
In addition, 28 million UK residents are without wills completely, the organisation found.
Unbiased.co.uk chief executive Karen Barrett commented: "These figures highlight the need for people to re-visit their will and update it each time a major financial or personal change happens in their lives."
Only then will they have peace of mind concerning their estates, she added.
Ms Barrett went on to claim that failing to update the documents can cause as many problems as not having one at all.
Recently, the expert suggested that failure to draw up a will can lead to family disputes and large inheritance tax charges.