Testamentary Capacity and Mental Illness – Ginger v Mickleburgh (2026)

A Will can be challenged and set aside if it can be shown that the deceased lacked ‘testamentary capacity’.

Banks v Goodfellow (1870)

The relevant legal test for establishing (testamentary) capacity was laid first down in the case of Banks v Goodfellow (1870) which provided a 4 limb test:

a) Did the deceased understand that they were making a will and the effects
b) Did the deceased understand the nature and extent of their estate being disposed of
c) Did the deceased understand as to those who would have claims on the estate
d) Was the deceased impaired by any disorder of the mind or delusions

Despite the age of this case – it is still good law and the right test to be applied.

The recent case of Helen Ginger and others v Robert Mickleburgh and others (2026) reviewed the fourth limb of this test in detail.

The Facts

This case concerned the estate of Michael Gwilliam who died on 17 February 2022. He was 79 years old at the time and suffering from dementia.

A will prepared by solicitors (Gwyn James) was executed by Michael on 3 December 2014. His sister (Sheila) and her son (Robert) were appointed as executors and trustees (the first and second Defendants). The will was accompanied by a Letter of Wishes dated 3 February 2015.

This provided a legacy of £31,000 to Joan, with the residual estate to be divided 25% to Joan, 25% to Sheila, 25% to Sheila’s 3 sons and 25% to his daughters.

Michael was survived by his 4 daughters – Helen, Georgina, Emily and Caroline (the Claimants). He was divorced from their mother Christine and had formed a relationship with Joan (the third Defendant).

A claim was bought to set aside the will on the bases that the deceased lacked testamentary capacity to make the will as he was suffering from delusions or disturbances of the mind.

The case was heard in August 2025 by HHJ Leslie Blohm KC with a 99-page judgment handed down on 23 January 2026.

Evidence was heard from a number of lay witnesses as well as expert evidence from Professor Chris Fox appointed on a single joint basis. He concluded that:

…Michael had been diagnosed with organic persistent delusional disorder, late onset schizophrenia, persistent delusional disorder, mild cognitive impairment and dementia. He concluded, based on the records, that Michael would have been suffering from paranoid symptoms which would have affected his decision making over this estate. Applying the Banks v Goodfellow test…at the date of the execution of the will:
(1) It was unlikely that Michael would have been able to comprehend and appreciate the claims to which he ought to give effect; and
(2) Michael had a disorder of the mind, psychosis/delusional disorder, that perverted his sense of right or prevented the exercise of his natural faculties in disposing of his property by will.

The judge also reviewed a large quantity of documentary evidence (medical records, social media, email communications, police reports, Michael’s diaries, etc)

The parties agreed that to succeed in the claim, the test under the fourth limb of Banks v Goodfellow was to show:

(1) That Michael was suffering from an insane delusion or disorder of the mind;
(2) Which arose from a mental disease;
(3) That was fixed and incapable of contrary persuasion by all reasonable efforts;
(4) And which had a causative effect on Michael’s testamentary dispositions.

The relationship between the two sides were highly acrimonious.

The judge was persuaded by the fact that Michael had never made a will, as he has intended for his daughters to inherit under the intestacy rules.

The fact that Michael had executed a Power of Attorney in 2018 did not sway the judge as he confirmed the test for testamentary capacity was different.

As to the evidence of the will writer, it was noted that

Where an experienced solicitor takes instructions for a will the taking of instructions may amount to good evidence of testamentary capacity (see Hughes v Pritchard [2022] EWCA Civ 386 at [79] per Asplin LJ). But whether that is so must depend on a close factual examination of the circumstances in which instructions are taken, and the knowledge of the testator and his circumstances by the lawyer

In this instance he noted that

• There was no fact to face contact
• Communications appeared to be through a party who would benefit from the proposed will
• The deceased was intending to disinherit his children who were his next of kin
• The deceased had been sectioned
• The Golden Rule was not followed appropriately

As such the judge set aside the will and therefore Michael was deemed to have died intestate with his daughters inheriting as next of kin (given that Joan as an unmarried partner could not inherit under the rules of intestacy).

Lessons Learnt

Testamentary Capacity is a complicated area and a wealth of evidence is usually required to successfully bring a claim.

Whilst the use of a solicitor can be a good preventive measure against challenge, it is not a fail safe if the solicitor has not followed the correct procedures and kept appropriate records – for example, in this case there was a lack of attendance note in the file.

The Golden Rule established in Kenwood v Adams (1975) confirms that where a testator is elderly or may be suffering from an illness, their will should be approved and/or witnessed by a medical practitioner who is satisfied as to the testator’s testamentary capacity. Whilst a medical practitioner (a mental health nurse) did see Michael, it was not with the intended purpose of assessing his testamentary capacity but to assess his medication only. His evidence at trial was that
he did not advise anyone that Michael was competent to make a will; and that he did not consider that Michael would have been able to make a valid will

Litigation is expensive and time consuming so should not be embarked on lightly without proper professional advice at the earliest opportunity

If you’re seeking legal advice regarding Wills, or Probate Disputes, or any Dispute Resolution matters, please contact our Dispute Resolution team on 0330 822 3451 to speak with one of our solicitors. Alternatively, you can request a callback.