Four ways to make your will watertight

The growth in challenges may make writing a will seem a bit pointless, but the experts stress it's still worth doing.

"Around two-thirds of people don't bother to write a will," says Margaret Windram, associate solicitor at Thomas Eggar.

"But this means their money will be distributed according to the rules of intestacy, which are rarely what you'd want."

Unless your affairs are incredibly simple, professional advice is essential.

"A solicitor will make sure everything is done correctly, but they'll also understand the potential issues so these can be taken into account in the will," explains Cordelia Brand, partner in the private client department at Howard Kennedy.

Professional will writers also understand how to make wills work. For example, rather than allocating financial amounts to different beneficiaries, they'll recommend awarding percentages to allow for any growth – or shrinkage – in the value of your estate.

They will also consider the financial planning aspects of your will, highlighting any areas where you could reduce the inheritance tax liability you're leaving.

A will must be signed by two independent witnesses at the same time. If this doesn't happen then the will can fail. Also, if a beneficiary acts as a witness, this can invalidate their inheritance. 

Supporting evidence can be useful too. A 'letter of wishes', explaining your plans, can help your executors when they deal with your will. 

You might also want to provide supporting evidence from a doctor, especially where the person writing the will is old or has health problems, to show that fraud has not taken place.

Your choice of executors can also make a difference. Helena Luckhurst, senior solicitor in the private client department at Speechly Bircham, says: "If your executors are close to your family and likely to act in the interests of your beneficiaries this will improve the chances of your estate being distributed according to your wishes."

It can also help to discuss your wishes with your family. "Talk to the people concerned so there are no surprises," Windram says. "It's better if people understand what you're doing, although it won't necessarily stop them challenging the will."

Once your will is written it's important to review it regularly. Ian Grant, vice-chairman of the regulatory board of the FPWPP, recommends you check it every five years: "Your life can change a lot in five years," he says.

"You should also check the will when there's been a major change in your circumstances."