The primary legal grounds for contesting a Will in England and Wales are lack of testamentary capacity, undue influence, lack of valid execution, lack of knowledge and approval, and fraudulent calumny or forgery. To successfully set a Will aside, a challenger must prove that the document does not represent the true, free, and capable intentions of the deceased at the moment of signing. Unlike claiming for a larger share of an estate, contesting a Will’s validity aims to have the document declared void in its entirety.

1. Lack of Testamentary Capacity: The Mental Threshold
For validity specialists, the most frequent point of attack is the testator’s state of mind. Under the long-standing legal test established in Banks v Goodfellow (1870), a person must be of “sound mind, memory, and understanding” to execute a valid Will. This requires the testator to understand the nature of the act, the extent of their assets, and the “moral claims” they ought to consider.
In 2026, we see a significant rise in challenges due to the “Social Masking” phenomenon associated with early-stage dementia. A testator may appear lucid in casual conversation with a solicitor but lack the executive function required to weigh complex family dynamics. If the Golden Rule—seeking a medical opinion for an elderly or ill testator—was ignored, the Will sits on shaky ground. We look for clinical evidence of cognitive decline, such as medical records or mini-mental state examinations (MMSE), to prove that the “mental machinery” required for a Will was broken.
2. Undue Influence: The “Overborne” Will
Undue influence is the “Skeptic’s” most difficult but often most necessary ground. It occurs when a testator is coerced into making a Will that they would not otherwise have made. The key legal word here is coercion. It is not enough to show that a beneficiary was “pushy” or “kind”; you must prove that the testator’s free will was completely overborne by pressure or fear.
Manipulation often happens behind closed doors, making direct evidence rare. However, in 2026, forensic investigators look for “Nodal Points” of influence, such as a sudden change in a Will immediately following a testator’s hospitalization or the bereavement of a spouse. If a beneficiary isolated the testator from their family or controlled their communications, the court may find that the resulting document is not the testator’s Will, but the influencer’s.
3. Lack of Valid Execution: The Technical Knockout
Sometimes, the most effective way to contest a Will is to ignore the “why” and look at the “how.” Under Section 9 of the Wills Act 1837, a Will must be signed in the presence of two witnesses who are both present at the same time. This is a strict, non-negotiable procedural requirement.
We often find that “DIY” Wills or those signed in a hurry fail the “Line of Sight” rule. If the witnesses were in a different room or if the testator signed the document before the witnesses arrived, the Will is “void on arrival.” For a Validity Specialist, an execution flaw is a “Technical Knockout”, it renders the entire document invalid without needing to spend months arguing about the testator’s mental state.
4. Lack of Knowledge and Approval: The “Reading” Defense
Even if a testator has capacity and isn’t being coerced, they must actually know and approve of the contents of the Will. This ground is often used when a Will is exceptionally complex or when the testator had significant sensory impairments, such as blindness or illiteracy.
If a solicitor cannot prove that they read the Will over to the testator or that the testator truly understood the “legal effect” of the clauses, the Will may be set aside. Suspicion is naturally heightened if the person who prepared the Will (or “helped” the testator) stands to benefit significantly from it. The court requires “exciting suspicion” to be removed by clear evidence that the testator knew exactly what they were signing.
5. Fraudulent Calumny and Forgery
Fraudulent calumny is a specific and insidious ground. It involves a beneficiary “poisoning” the testator’s mind by making false and dishonest claims about another natural beneficiary. If a child tells their parent that their sibling is a thief, knowing it to be false, solely to have that sibling written out of the Will, that is fraudulent calumny.
Forgery, while rarer, involves the physical faking of a signature or the “splicing” of pages into an existing Will. In 2026, we utilize forensic handwriting experts and ink-dating technology to determine if a signature is authentic or if the document has been tampered with post-execution.
The Strategic Pivot: Validity vs. Unfairness
It is vital to distinguish between contesting a Will’s validity and making a claim under the Inheritance Act 1975. If the Will is legally “perfect” but you were left out unfairly, you are in “Liability Lane.” If the Will itself is a “fake” or “forced,” you are in the “Validity Moat.” A Validity Specialist focuses on the latter to have the document destroyed entirely.
FAQs
Q1: How long do I have to contest a Will?
There is no strict time limit for challenging the validity of a Will (e.g., fraud or lack of capacity), but you should act before probate is granted. Once assets are distributed, they are notoriously difficult to recover. However, if you are claiming for “unfairness” under the Inheritance Act 1975, you have a strict 6-month window from the date of the Grant of Probate.
Q2: What happens if I win and the Will is declared invalid?
If a Will is set aside, the estate usually reverts to the previous valid Will. if no previous Will exists, the estate is distributed according to the Rules of Intestacy, which prioritize spouses, children, and close blood relatives in a specific legal order.
Q3: Can I stop probate while I investigate these grounds?
Yes. You should lodge a Caveat at the Probate Registry immediately. This prevents the Grant of Probate from being issued for six months (renewable), giving your legal team time to submit a Larke v Nugus request to the drafting solicitor and gather the evidence needed to prove one of the grounds mentioned above.
Reclaiming the Truth
Contesting a Will is a forensic pursuit of the truth. It requires moving past emotions and focusing on the hard evidence of capacity, execution, and influence. For “The Skeptic,” the goal is to ensure that a document signed in a moment of weakness or under the shadow of manipulation does not become a permanent legal reality.
Unsure if you have enough evidence to challenge? Download ‘The Capacity Evidence Checklist‘ to see if your case meets the legal threshold for a validity challenge.
Let’s Do This Together
Contesting a will could become an overwhelming experience if not accompanied by expert guidance and support. Our mission is to provide you with all the needed information, support, and authority to get through this journey, with only one goal in mind: Fairness.
To our team, this process is not about winning; it’s about claiming what was yours from the beginning. Don’t forget to read our complete guide on the Lack of Mental Capacity here.
Get your free, no-obligation case assessment. Call 08002980029 or visit contestawilltoday.com


