Have you ever asked yourself the question, “can you write a Will without a solicitor”? Well, a recent High Court ruling handed down in January 2026 has brought the risks of an improperly prepared Will into devastating focus.
Four sisters spent years fighting to uphold their father’s true wishes after his own Will (written when he was suffering from serious mental illness) was used to redirect the majority of his estate away from them. The case is a powerful reminder that making a Will is only part of the picture. Having it prepared by a qualified, regulated solicitor who properly assesses mental capacity could be the difference between your wishes being honoured and your family facing years of costly, distressing litigation.
The Gwilliam case – what happened
Michael Gwilliam, a Gloucestershire man, had always been clear: he did not want to make a Will. His intention was to die intestate so that his estate, valued at between £750,000 and £1 million, would pass automatically to his four daughters under the strict rules of intestacy.
But in 2014, the same year he was sectioned under the Mental Health Act following a diagnosis of late onset schizophrenia, Gwilliam made a new Will. The condition caused him to suffer severe delusions, including the belief that his daughters and neighbours were conspiring against him and that his daughters were trying to have him locked up for financial gain. In his Will, he left only a quarter of his estate to his daughters, with the remainder split between his sister, former partner and three nephews.
When Gwilliam died in 2022, his daughters discovered the Will and challenged its validity on the grounds that he lacked the mental capacity to make it. The High Court agreed. The judge found that Gwilliam’s fixed delusions about his daughters had robbed him of the testamentary capacity required to make a legally valid Will, and the document was declared invalid. His estate will now pass to his daughters under intestacy rules – as he had always intended.
A Will is only as good as the process behind it
One of the most significant details to emerge from the Gwilliam case was the role of the Will writing firm involved. The Will was prepared by an experienced paralegal who told the court they believed Gwilliam had the capacity to make it. But crucially, a mental health nurse who was present at the time confirmed he was never asked to formally assess Gwilliam’s capacity.
This failure to follow what the legal profession calls the “golden rule” proved fatal to the Will’s validity.
KEY LEGAL PRINCIPLE
The “golden rule” in Will writing
The golden rule holds that where there is any doubt about a testator’s mental capacity, a medical professional should be asked to assess capacity before the will is signed, and their assessment should be documented. Had this been followed in the Gwilliam case, the Will would likely never have been made, or would have been far harder to challenge after his death. The daughters’ solicitor, Clare Cox of Willans LLP, stated plainly: had a medical assessment been produced, it would have shown Gwilliam lacked capacity to write a Will.
The firm the paralegal worked for did not reply to requests for comment. But the case raises serious questions about the standard of care provided by unregulated Will writing services, and about what families should look for when making this most important of legal documents.
What is testamentary capacity, and why does it matter?
Testamentary capacity is the legal term for the mental ability required to make a valid will. It is not simply about whether a person appears to understand what they are doing, it sets out specific conditions that must all be met at the time the Will is signed in front of the required two witnesses.
To have testamentary capacity, a person must:
- Understand the nature of making a Will and its effect - that they are creating a document that will determine what happens to their estate after death.
- Understand the extent of their estate - they must have a general awareness of the money, property and assets they own.
- Understand the claims of those who might reasonably expect to benefit - including family members and loved ones, even if the intention is to exclude them.
- Not be suffering from a disorder of the mind that poisons their affections, perverts their sense of right, or prevents the exercise of their natural faculties in disposing of their property.
This last point was central to the Gwilliam case. The judge found that Gwilliam’s delusions (that his daughters were stealing from him, conspiring against him, and had him sectioned for financial gain) were so fixed that they corrupted his understanding of who should benefit from his estate. His apparent ability to converse and appear rational at times was not enough: the delusions had fundamentally undermined his capacity to make a Will that reflected his true wishes.
£750k - £1m
Value of Michael Gwilliam’s estate at the centre of the dispute
4 years
From Gwilliam’s death in 2022 to the High Court ruling in 2026
60%
Of UK adults don not have a valid, up to date Will in place
What else can a Will be challenged on?
The Gwilliam case succeeded on the grounds of lack of testamentary capacity – but it is far from the only basis on which a Will can be challenged in court. Common grounds include:
Lack of testamentary capacity
The person did not have the mental capacity required to make a legally binding Will, as in the Gwilliam case. Often arises in cases of dementia, severe mental illness, or serious physical illness.
Undue influence
A beneficiary pressured or manipulated the person into making or changing their Will in a way that does not reflect their genuine wishes.
Failure of formal requirements
The will was not properly signed or witnessed in accordance with legal requirements – rendering it invalid regardless of its contents.
Fraud or forgery
The document itself or a signature on it was fraudulently created or altered, or false statements were made to induce the person to change their Will.
Each of these risks is substantially reduced, and in most cases eliminated entirely, when a Will is prepared by a qualified, regulated solicitor who follows a thorough, documented process and understands their obligations around capacity assessment.
Can you write a Will without a solicitor?
Legally, yes. There is no requirement in Scotland or England and Wales to use a solicitor when making a Will. You can write your own Will, use an online template, or instruct an unregulated Will writer. Many people do.
But the Gwilliam case illustrates with painful clarity why the question should not be whether you can make a Will without a solicitor – it is whether you should.
The UK Will writing industry is not fully regulated. Anyone can set themselves up as a Will writer regardless of their legal qualifications, training, or understanding of issues like mental capacity. There is no mandatory professional body, no required insurance, and critically, no guaranteed standard of care when assessing whether the person making the Will is actually capable of doing so.
A Will that appears valid on its face can be challenged and overturned after your death. By then, it is too late for corrections to be made, and the burden falls entirely on your family. The cost of getting it wrong, in legal fees, time, and emotional toll, can far exceed the cost of getting it right in the first place.
A qualified solicitor like Jones Whyte is regulated – in Scotland by the Law Society of Scotland, in England and Wales by the Solicitors Regulation Authority. As a regulated firm, we carry professional indemnity insurance, we are trained to identify and document capacity issues, and are accountable for our work. When capacity is in doubt, we know to follow the golden rule. An unregulated Will writer may not. We always recommend seeking legal advice when it come to writing a Will.
The risks of DIY Wills and unregulated Will writing
The Gwilliam case involved a paralegal working for a legal firm, not a DIY Will.
Yet even with professional advice involved, the failure to properly assess and document capacity created a Will that was ultimately invalid. The risks with DIY Wills are even greater. Common mistakes include:
No capacity assessment
A DIY Will or online template has no mechanism for identifying or documenting capacity. If this is later challenged, there is no contemporaneous evidence to rely on.
Ambiguous wording
Unclear or contradictory language that creates disputes about what was actually intended, often only discovered after the person has died.
Incorrect execution
Basic details such as missing beneficiaries, improperly signed and witnessed documents, or alterations made after signing that invalidate the Will entirely.
Failure to account for all assets
Omitting property or property abroad, personal possessions, pensions, business interests, or digital assets that then fall outside the scope of the Will.
Outdated provisions
A Will that no longer reflects changed circumstances such as divorce from a previous relationship, new children, the death of a named beneficiary can cause unintended consequences during an already difficult time for your family.
Failure to consider legal rights in Scotland
In Scotland, certain family members have prior rights and legal rights to an estate regardless of what a Will says. A solicitor familiar with Scots law ensures these are properly addressed.
What a solicitor does that an unregulated Will writing service cannot
When you instruct a solicitor at Jones Whyte to prepare your Will, the process goes far beyond recording your wishes on paper. Our approach includes:
- A thorough discussion of your circumstances, assets, family situation, and intentions ensuring nothing relevant is overlooked.
- Assessment and documentation of your testamentary capacity at the time of signing, providing a clear contemporaneous record that protects your Will against future challenge.
- Application of the golden rule where there is any doubt about capacity, including liaison with medical professionals where appropriate.
- Clear, precise legal drafting that leaves no ambiguity about your intentions.
- Advice on inheritance tax planning, including making best use of available allowances, specific gifts and the potential role of trusts in protecting your estate.
- Consideration of whether a Power of Attorney or other estate planning tools should be put in place alongside your Will.
- Free of charge safe storage of your Will and a clear process for reviewing and updating it as your life and circumstances change.
When should you review or update your Will?
It goes without saying, but a Will should be reviewed regularly – at a minimum every three to five years, and whenever significant life events occur. You should consider updating your will if:
- You marry, enter a civil partnership, divorce, or separate.
- You have children or grandchildren, or there are changes in your family structure.
- A named beneficiary or executor dies.
- You acquire, dispose of, or inherit significant assets
- Your health changes - particularly where cognitive decline or serious illness becomes a factor. Reviewing your Will while you clearly have capacity is far better than waiting.
- Tax or succession law changes in a way that affects your estate planning.
The Gwilliam case is a reminder that the time to think about your Will is not when a health crisis has already occurred. By then, the window for making valid legal arrangements may already have narrowed, or closed entirely. The best time to consider writing a Will is as early as possible. You can use our online Will writing service to get the process started.
Intestacy Rules – what happens if you die without a valid Will?
If you die without a valid Will, whether because you never made one, or because the Will you made has been declared invalid, your estate is distributed according to the rules of intestacy, which means the law decides who inherits. In the Gwilliam case, this outcome was actually what the family wanted: Michael had always intended to die intestate so his daughters would automatically inherit equally.
But intestacy does not always produce the outcome you would choose. The rules do not recognise unmarried partners and civil partners, regardless of the length of the relationship. They may direct assets to estranged relatives rather than those closest to you. And they can result in unnecessary inheritance tax implications that a properly structured Will would have avoided.
Our guide to intestacy law in Scotland explains exactly how the rules work and who inherits in the absence of a valid Will.
Protect your estate. Protect your family.
Our specialist Wills and estate planning solicitors are here to help you put the right arrangements in place – clearly, correctly, and with the legal protection your family needs and deserves.
Jones Whyte
Jones Whyte is a full-service law firm with offices in Glasgow and Edinburgh, authorised and regulated by the Law Society of Scotland and the Solicitors Regulation Authority. Our dedicated private client team hold dual-qualifications across Scotland, England and Wales.
Please note: This article is for general information purposes only and does not constitute legal advice. It should not be relied upon as a substitute for professional legal advice tailored to your specific circumstances. If you need advice on a legal matter, get in touch with our team.
