As more and more people opt to use do-it-yourself will-writing services, advertised online for nothing more than a few pounds, so the High Court has recently seen a sharp rise in the number of costly inheritance disputes – from 227 two years ago to 368 over the course of the last year.

Indeed, what is initially saved in solicitor’s costs by writing your own last will and testament, could turn out to be the most expensive mistake you ever make.

Writing a will can be a legal minefield, not least given the complexity of many modern family structures, leading to all sorts of mistakes and oversights that can impact on the validity of a will or a particular provision contained within it.

The net effect is that those who ought to benefit may miss out, or worse still, the value of your estate is entirely diminished in legal fees in circumstances where the will is contested. In some cases, the costs incurred can even exceed the value of your estate, potentially leaving your loved ones with a hefty bill to pay.

What are the most common mistakes?

One of the most common mistakes when drafting a DIY will is the manner in which it is executed. A will is a legal document that needs to be written, signed and witnessed correctly to be valid. In the event that the will has not been properly executed in accordance with the rules, it could be declared invalid.

Another common mistake is a failure to make provision for any contingencies, in other words, what you would want to happen if any beneficiary should die before you. You may, for example, want their share to be inherited by another named individual or, alternatively, for that share to be divided up between the remaining beneficiaries.

You may also want any inheritance to be held on trust, for example, for any children under the age of 18, yet incorporating a trust arrangement into your will can be extremely complicated and, as such, easy to get wrong.

What happens if my DIY will is not valid?

If you die without leaving a valid written will, the law will determine who inherits what you own. In legal terms this is known as dying intestate. If you die intestate your money, property and personal possessions will be distributed in accordance with the rules on intestacy, rather than with your wishes.

This is especially significant if you have loved ones that depend on you financially, particularly if you are unmarried. Ensuring that your will is legally compliant and clearly drafted can avoid any unnecessary disputes after you have died, thereby protecting your loved ones from future financial uncertainty.

Should I seek expert advice when drafting a will?

By securing expert advice from a specialist in wills and probate, you can have the peace of mind that your will is free from errors or omissions, thereby minimising the risk of any costly and distressing litigation for your loved ones after you die.

You can also feel confident that it accurately reflects your wishes and provides for any contingencies, so that when the time comes, your money, property and possessions are distributed in the way that you intended.

In particular, expert guidance should always be sought for the following matters, although this list is by no means exhaustive:

• To make financial provision for your partner where you are unmarried or not in a civil partnership.

• To make financial provision for your spouse, civil partner or cohabiting partner where you jointly own property.

• To make financial provision for any children from a previous relationship where you are married or in a civil partnership

• To make arrangements within your will for looking after any children under the age of 18

• To set up a trust within your will to manage any inheritance of a beneficiary aged 18 or under

• Any form of estate planning and inheritance tax issues.