Two in five homeowners do not have a will, according to insurer Royal London, meaning that their property could pass to the wrong person when they die.
Not leaving a will - known as dying intestate - can also make it more complicated for those left behind to administer the estate.
Here we look at why not making a will could leave your loved ones at risk, and how to make a will with the right safeguards.
Royal London found that one in five people hadn't made a will because they didn't think they had anything of value to pass on. But of these, one in six own a property.
The research, which was carried out last October, also uncovered a substantial number of older homeowners without wills.
Of people aged over 55 who don't have a will, 16% own a home outright or with a mortgage.
Some homeowners said they struggle to decide who would benefit from the will.Choosing who should act as executor and trustee - someone who sorts out your estate and carries out your wishes after death - was the most difficult part of writing a will.
If you die without a will, your estate will be shared out according to the intestacy rules.
This means you could inadvertently disinherit the people closest to you, which could include those who were dependent on you.
In England and Wales, if you don't update your will when you marry, it'll be invalidated and your estate will be subject to the intestacy rules.
It's even more important for co-habiting couples to have wills than it is for married people or those in civil partnerships.
That's because if you're not married, the surviving partner has no automatic rights to inherit under the intestacy rules. In these cases, any children you have will inherit the estate.
If you die without a will and don't have a spouse or any children, your estate will go to other relatives. This is decided by a set order of priority, starting with parents, followed by brothers and sisters.
If it takes time for the beneficiaries to be tracked down, the property can deteriorate.
In a case looked at by , a man was tracked down by heir hunters after a distant cousin died. He stood to inherit a house, but in the months it had taken to find him, vandals and mould had wreaked thousands of pounds of damage and devalued it.
Had there been a will, it would have been clear who was the beneficiary and an executor would have dealt with the property.
It all hinges on if you are tenants in common or joint tenants.
As tenants in common, if you die, your share of the house goes to whoever is named in your will, but if you don't have one, it'll be distributed according to intestacy rules.
If you are joint tenants, the property would automatically go to the surviving owner.
In a recent case dealt with by Which? Wills, a young man had bought a holiday home in the UK with friends without discussing what would happen if one of them died.
He realised that as they were tenants in common, his share of the property would be inherited by his family under intestacy rules, but he wanted it to go to his friends instead and so made a will to ensure this happens.
Whether a joint homeowner has made a will or not, their share could be inherited by someone who has a very different outlook on how the property should be managed. To avoid unforeseen twists of fate, it's vital to agree on what you and the other joint owners would want and for all parties to reflect this in their wills if necessary.
If you own a property abroad, the law in that country will determine what happens to it when you die. As such, it's advisable to make a will in the relevant country as well as one covering your assets in the UK.
Drawing up a valid will needn't be lengthy or difficult. It's possible to write one online in 30 minutes, saving days or years of potential heartache for loved ones later on.
Once you're ready to write one up, you can approach a lawyer or online service.
You can choose from three levels of service: