Common Mistakes That Can Invalidate Your Will and How to Avoid Them

Making a Will is a crucial step in safeguarding your future wishes, but it’s not just about deciding who inherits what. For a Will to be legally valid and enforceable, it must be made correctly – and with a full understanding of the legal requirements involved.

At Franklins Solicitors, we regularly advise clients who are unaware of the potential pitfalls when it comes to writing and signing a Will. Issues around capacity, execution and DIY or online solutions can lead to serious complications – or even render a Will invalid.

For a Will to be valid, the person making it (the testator) must have the mental capacity to do so. This is known as “testamentary capacity” and is a legal requirement under UK law.

The testator must:

As we are all living longer, cases involving capacity are becoming more common. Conditions such as dementia or mental health disorders don’t necessarily prevent someone from making a Will, but they do require extra care and often medical evidence to confirm capacity at the time of signing.

If there is any doubt, it is essential to seek professional legal advice early to avoid disputes later.

While it is legally possible to write your own Will by hand, we strongly advise against it. Homemade Wills, including handwritten or downloaded templates, are more prone to errors in language, format, and execution.

These documents are often:

During their lifetime, people usually do not pay CGT when selling their main home because of Principal Private Residence Relief (PPRR).

For Executors, the rules are different. PPRR is only available if:

A Will may seem straightforward on the surface, but the law surrounding estates, tax, and inheritance is anything but. One missing clause or a poorly chosen word can lead to disputes, delays, or your wishes not being carried out at all.

Online Will-writing services are widely advertised, but they often offer a one-size-fits-all approach that lacks the rigour and personalisation of professional advice. They typically do not account for complex family situations, blended families, business ownership, overseas assets, or vulnerable beneficiaries.

Even for seemingly simple estates, we regularly see clients needing to “fix” or challenge Wills made using online platforms – often at much greater cost than having done it properly in the first place.

One of the most common reasons a Will becomes invalid is incorrect witnessing. For a Will to be legally binding, it must be:

Crucially, witnesses cannot be beneficiaries of the Will, nor can they be married to or in a civil partnership with a beneficiary. If a beneficiary acts as a witness, they will lose their inheritance under the Will, though the rest of the document may remain valid.

Example: If you name your daughter as a beneficiary and she witnesses your Will, she will not receive her inheritance. Even if your son-in-law witnesses the Will, your daughter will lose her entitlement because the witness is married to a beneficiary.

A Will should reflect your current circumstances. Major life events can significantly affect how your estate should be distributed, yet many people forget to review their Will after these changes occur.

Marriage automatically revokes any existing Will unless it was made in contemplation of that specific marriage. This means if you marry after making your Will, you will effectively die intestate unless you make a new Will.

Divorce does not revoke a Will, but it does remove an ex-spouse as a beneficiary or executor – though other provisions remain in place.

We recommend reviewing your Will every five years, or after:

If you have children under 18, your Will should name guardians who will care for them if both parents die. Without this provision, the courts will decide who looks after your children – and their decision may not align with your wishes.

This is one of the most important reasons for parents to make a Will, yet it is frequently overlooked in DIY and online Wills, which often fail to prompt for this information.

A valid Will is not just a piece of paper – it’s a legally binding document and arguably one of the most important you will make. Getting it wrong can have life-changing consequences for those you leave behind.

At Franklins, we work closely with our clients to ensure that every Will is:

Whether you’re writing your first Will or updating an existing one, our experienced Private Client team is here to support you every step of the way.

If you are concerned about an existing Will or would like to make a new one, contact our Wills and Probate team for clear, practical advice.