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What's needed with a claim that a will is invalid?

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Whats needed with a claim that a will is invalid?

You may be considering a claim against the validity of a will, but do not know what you need to establish to be successful. Here at Birkett Long we have a team of specialists who have experience in every way to challenge a will.

The validity of a will can be disputed on a number of different grounds, which include:

  • The deceased’s lack mental capacity to make the will, known as testamentary   capacity
  • The deceased was unduly influenced into making the will
  • The will is a forgery
  • The will does not comply with the necessary formalities
  • The deceased did not know and approve the contents of the will

It is not uncommon for a will to be challenged on a number of different grounds.

What do I need to prove to successfully challenge the validity of a will?

Each ground has a different legal test which needs to be fulfilled before the will is found to be invalid.

Lack of mental capacity (testamentary capacity)

With a claim that the deceased lack the mental capacity to make a will (also known as testamentary capacity) you need to establish that the deceased did not fulfil the Banks v Goodfellow test. This is a case which established that for someone to have sufficient mental capacity to make a will, they must:

  • Know they are making a will, and what the will does
  • Know the approximate size of their estate at the time they make the will
  • Appreciate who might expect to inherit from them, but they do not have to include them in the will
  • Not be suffering from a disorder of the mind, or insane delusions, which affects the disposition of the deceased’s estate.

Undue Influence

Establishing a will is invalid due to undue influence is notoriously difficult. Largely because you need to establish that the deceased was influence, and this influence overpowered the deceased’s ability to do what they wanted.

The five things which need to be established are:

1.    There was an opportunity to exercise influence

2.    That there was an actual exercise of influence

3.    The actual exercise of the influence was in relation to the will

4.    The influence was undue i.e. went beyond mere persuasion

5.    That the will was brought about by these means


Undue influence does not have to be physical. It can be verbal abuse, or verbally talking to someone who is old or weak. Influence may also be a ‘drip, drip’ effect where someone makes a number of comments over a long period.

Mere persuasion must not be mistaken for influence. It is perfectly accepted for someone to suggest to someone making a will that they should be included, or even try to persuade the person. What’s important is when it affects the person’s ability to exercise their own free will.

One of the difficulties in establishing undue influence is having proof. The person alleging undue influence must prove it. This can be difficult as often the coercion will take place behind closed doors. The court can find undue influence when there is no direct witness evidence from drawing an inference of undue influence from other proven facts. However, it is not an easy task.

Fraudulent calumny

Another ground which is similar, but different, to undue influence is fraudulent calumny. This is when A poisoned the deceased’s mind against B, who otherwise would have been a beneficiary. A must have poisoned the deceased’s mind against B by making dishonest allegations about B’s character, which A either knows to be untrue or does not care if it is true or not.

Fraud or forgery

A will is invalid if it can be established that it is a forgery. This often comes does to expert evidence to look at the signature on the will. However, these challenges can be very difficult and cases have been unsuccessful even when two experts have agreed that the signature was a forgery.


S.9 of the Wills Act 1987 sets out how the formalities of a will.

For a will to be valid, it must:

-       Be in writing

-       Signed by the deceased, or by someone else at the deceased’s direction

-       The Deceased must sign the will (or acknowledge their signature) in the presence of two witnesses, who must also sign the will

Please note that there is a temporary amendment allowing wills to be witnessed via video link during the Coronavirus pandemic. Please see my colleague’s blog on the same here 

Knowledge and approval

A will is only valid if the deceased knew and approved it’s contents when they signed it. The will must truly represent the deceased’s wishes. Therefore, if the deceased did not know the provision of the will and/or did not approve the provisions, then the will is invalid.

This often goes hand in hand with lack of capacity, as someone who lacks capacity cannot understand the contents of the will and therefore cannot approve it’s contents.

How do I prove the will is invalid?

The evidence needed to establish a will is invalid can depend on the ground upon which it is challenged. The most common pieces of evidence can be the will file (often obtained by making a Larke v Nugus request), the deceased’s medical records and witness statements from people who knew the deceased or were involved in the preparation of the will.

It is also common to obtain an expert report on the deceased’s mental capacity or on whether the will is a forgery, if those are the grounds on which the will is being challenged.

What happens if a will is invalid?

If you are successful in challenging the validity of a will, then the estate will be distributed in accordance with the previous will and it is possible to challenge more than one will. If there is no previous will, the estate will be disputed in accordance with the rules of intestacy.  Therefore, before considering challenging a will, you need to establish whether you will be better off under the previous will, or the rules of intestacy.

If you believe a loved one’s will may be invalid, please contact our team of experts at Birkett Long who will be happy to discuss your case.