This guide is maintained as a current resource for September 2026 and covers only the laws of England and Wales. Information is for general guidance, not legal advice. Consult a qualified solicitor for advice specific to your situation.
Understand when a will can be overturned in England and Wales due to lack of knowledge and approval. This detailed guide covers legal grounds for challenge, evidence requirements, procedural steps, time limits, and practical considerations under UK probate law.
A will is a legal declaration of how a person (the testator) wishes their estate to be distributed after death. For a will to be valid in England and Wales, it must meet legal formalities under the Wills Act 1837 and must also reflect the true understanding and intent of the testator. One recognised ground to challenge a will's validity is lack of knowledge and approval - meaning the person signing the will did not genuinely understand or approve its contents. This article explains what lack of knowledge means, when such a challenge may succeed, how the law approaches these disputes, and what practical steps a potential challenger can take.
What Does “Lack of Knowledge and Approval” Mean?
Even if a will is correctly signed, witnessed, and executed, the law presumes that the testator knew and approved the contents of the will. This presumption can be overturned if there is evidence that the testator did not understand or was unaware of the terms of the will at the time of execution. In such circumstances, the will may be treated as invalid because it did not truly represent the testator's intentions.
The concept is distinct from other grounds for contesting a will - such as lack of testamentary capacity or undue influence - and applies where the person had mental capacity but lacked understanding of what they were signing.
The Legal Basis for Challenging a Will on This Ground
Presumption of Knowledge and Approval
Under English law, when a will is properly executed (signed by the testator with two independent witnesses present), there is a rebuttable presumption that the testator both knew and approved its contents. To challenge on the basis of lack of knowledge, the challenger must present evidence that casts serious doubt on this presumption.
Standard of Proof
The court applies the civil standard of proof - on the balance of probabilities - to determine whether the testator genuinely knew and approved the will's terms. This means the claimant must satisfy the court that it is more likely than not that the testator did not understand the content at the time of signing.
Link to Testamentary Capacity
Lack of knowledge and approval is distinct from lack of testamentary capacity, although the two can overlap. A person might have sufficient mental capacity to make a will but still fail to understand the specific contents of a complex document they have signed.
When Lack of Knowledge and Approval May Arise
A challenge on this ground is not common, but there are scenarios where it may arise, including:
- Vulnerability or communication impairment: The testator was blind, illiterate, deaf, or otherwise unable to review the document themselves and no proper explanation was provided.
- Suspicious circumstances: There are unusual features about the will - for example, a radical departure from earlier versions without explanation or involvement by a beneficiary in drafting or execution.
- Errors or unfamiliar language: The will contains uncharacteristic language, spelling mistakes, or terms that the testator could not reasonably be expected to understand.
- Lack of independent advice: The testator relied entirely on someone with an interest in the will for explanation, and there is evidence that explanations may have been misleading.
In these cases, evidence that the testator did not read, hear, or otherwise understand the contents of the will may support a challenge on this ground.
Key Legal Principles and Case Law
Fuller v Strum
In Fuller v Strum, the court explained that where knowledge and approval are put into question, the burden of proof falls on the person propounding the will to show that the testator did know and approve the contents. In situations where suspicious circumstances are present, the court may require positive evidence of understanding rather than relying on the presumption arising from valid execution.
Perrins v Holland
In Perrins v Holland, the court confirmed that it is sufficient for knowledge and approval if the testator understood the terms when they were summarised to them - it is not necessary for every clause to be read aloud. However, this indicates the testator must genuinely understand the effect of the will rather than just its existence.
Practical Steps to Challenge a Will for Lack of Knowledge
1. Review the Circumstances Around Execution
Start by examining how the will was prepared and executed. Obtaining the original document, any drafts, and notes from the drafter (for example, the solicitor) can be critical.
2. Collect Evidence of Understanding or Lack Thereof
Relevant evidence includes:
- Medical records concerning cognitive status and communication ability.
- Witness statements from professionals, family, or carers present at signing.
- Notes from the will drafter about how the will contents were explained.
- Comparison with earlier wills or testamentary intentions.
3. Consider a Caveat or Immediate Action
If probate has not yet been granted, applying for a caveat can temporarily prevent the grant while the issue is investigated.
4. Seek Specialist Legal Advice Early
Challenging a will on this ground involves complex evidential issues. A solicitor specialising in contentious probate can assess your case, advise on evidence requirements, and help prepare court applications.
Time Limits and Procedural Considerations
There is no fixed statutory time limit for challenging a will's validity on this ground, but claims should be brought promptly to preserve evidence and protect estate assets. In many cases, claimants issue proceedings within a few months of the grant of probate. Delay can weaken a case or preclude effective remedy if assets are already distributed.
Risks and Common Challenges
- Evidential complexity: Demonstrating lack of knowledge and approval is fact‑specific and often difficult. Strong evidence is required.
- Overlap with other grounds: Challenges may involve related grounds such as undue influence or lack of capacity, which have distinct legal tests.
- Costs and delay: Contentious probate litigation can be time‑consuming and costly. Parties should consider whether alternative claims (such as under the Inheritance (Provision for Family and Dependants) Act 1975) might provide a different route for redress.
Key Takeaways
A will can be overturned in England and Wales on the basis of lack of knowledge and approval where the person making the will did not genuinely understand or approve its contents at the time of execution. This is a distinct ground from lack of capacity or undue influence and requires specific evidence to displace the presumption of knowledge arising from valid execution. Challenges on this basis are complex and fact‑driven, and typically require careful investigation and specialist legal assistance.
