Standard Life says half of the people in the UK do not have a will and millions could die intestate.
Its research also reveals that 74 per cent have not drawn up plans for power of attorney.
It says 3 per cent of people own property abroad but do not have a will in those countries to cover the property.
Standard discovered that people with children are less likely to have a will than those without children, with 43 per cent versus 52 per cent not having wills.
People who are married or co-habiting are less likely to have a will than people who are widowed, separated or divorced, at 53 per cent compared with 59 per cent.
National development specialist estate planning Julie Hutchison says: “A will and power of attorney should be bread and butter planning for everyone.
“Despite these being some of the most important documents that you ever sign, 50 per cent of those in our survey seem to favour the ostrich approach but sticking your head in the sand is not the answer.”