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.
Detailed guide explaining the legal grounds for challenging a will in England and Wales, including lack of testamentary capacity, undue influence, improper execution, fraud, lack of knowledge and approval, rectification issues and reasonable provision claims under the Inheritance (Provision for Family and Dependants) Act 1975.
In England and Wales, a will is generally treated as the legal expression of a person's final wishes about how their estate should be distributed after death. However, under certain circumstances, it may be possible to challenge a will if there are valid legal grounds suggesting the document is defective, unfair, or fails to make reasonable provision for someone who has a claim. Contesting a will is a specialised area of law involving civil claims in the County Court or High Court, potentially under multiple legal principles. This article explains the recognised legal grounds for challenging a will, the practical context for each, and how these challenges interact with the estate administration process.
1. Lack of Testamentary Capacity
One of the fundamental requirements for a valid will is that the person who made it (the testator) must have had testamentary capacity at the time of execution. This means the testator must have:
- understood the nature and effect of making a will;
- appreciated the extent of their assets; and
- been aware of the claims that might be made by people who might reasonably expect to benefit.
If a testator lacked sufficient mental capacity - for example because of dementia, severe illness, cognitive impairment or other conditions affecting understanding - the will may be invalidated on this ground. Challengers often need medical and expert evidence to support such a claim.
2. Lack of Knowledge and Approval
Even if a testator had mental capacity, they must also have knowledge of and approve the contents of the will. This ground focuses on whether the testator was aware of what the document said and understood it at the time of signing. Situations where this ground may arise include:
- the testator was illiterate, blind or otherwise unable to read the document without adequate explanation;
- the will contains unexpected terms that the testator did not discuss; or
- evidence suggests the testator was not aware of changes made shortly before execution.
This ground is distinct from capacity: a testator may be mentally capable yet still unaware of the content or implications of the specific document they signed.
3. Lack of Valid Execution
The Wills Act 1837 imposes strict formal requirements for a valid will: it must be in writing, signed by the testator and witnessed by two independent adults present at the same time. If these formalities have not been properly followed, the will may be invalid for lack of valid execution. Common issues include:
- absence of two good witnesses;
- irregularities in signing or witnessing;
- improper alterations to the document after signature.
Evidence from witnesses and examination of the document itself may be needed to support this ground.
4. Undue Influence and Coercion
A will must reflect the free and voluntary wishes of the testator. Undue influence occurs when someone exerts pressure, coercion or manipulation on the testator to cause them to make or change the will in a way that does not reflect their authentic intentions. This ground does not involve ordinary persuasion but pressure that overcomes the testator's free will, such as threats, intimidation, manipulation, or exploitation of vulnerability. Because undue influence is often exerted in private, proving it can be challenging and usually requires careful assembly of evidence, such as patterns of behaviour or changes in the document that correspond to periods of dependency.
5. Fraud and Forgery
A will may be contested if there is evidence of fraudulent conduct or forgery. Examples include:
- the will is entirely or partially forged;
- the signature is fake;
- parts of the document were altered without the testator's knowledge;
- the testator was misled about the nature of the document they were signing.
Such claims often require expert examination, such as handwriting analysis, and may also intersect with criminal law because fraudulent activity is both a civil and criminal matter.
6. Rectification and Construction Claims
The terms of a will may not truly reflect what the testator intended if there was a clerical error, misinterpretation by the drafter, or a failure to record instructions accurately. In such cases, the court can be asked to rectify the will to reflect the true intentions of the testator or provide a construction of ambiguous terms. Although this does not invalidate the will entirely, it can correct errors that would otherwise frustrate the testator's objectives. These applications are strictly controlled and typically must be made within specific timeframes after probate is granted.
7. Claims for Reasonable Financial Provision
A separate but related route arises under the Inheritance (Provision for Family and Dependants) Act 1975. Even if a will is valid under strict legal formalities, it may fail to make reasonable financial provision for certain claimants. Eligible individuals include:
- spouses and civil partners;
- children and those treated as children of the family by the deceased;
- dependent cohabitants who lived with the testator for a minimum period; and
- persons financially maintained by the deceased.
Under this Act, a claimant can ask the court to adjust the distribution so that reasonable provision is made for them. Successful claims may result in the court ordering specific financial awards or transfers from the estate. This ground does not invalidate the will but alters the way the estate is distributed.
Practical Context and Evidence
Challenges to a will are often complex, involving detailed factual investigations. Medical evidence, witness statements, legal documentation, and evidence of communication or behaviour around the time the will was made may all be necessary to support a claim. Executors and beneficiaries should seek specialist legal advice early to assess the strength of prospects and possible remedies. Because contested probate cases can be costly and protracted, understanding the specific grounds and required evidence is essential.
Key Takeaways
In England and Wales, wills can be challenged on specific legal grounds, including lack of testamentary capacity, lack of knowledge and approval, failure to comply with execution formalities, undue influence, fraud or forgery, and errors in drafting. Additionally, separate statutory claims under the Inheritance (Provision for Family and Dependants) Act 1975 allow eligible persons to seek reasonable financial provision. Challenges typically require substantial evidence and legal process through the courts. Understanding these grounds helps potential claimants and executors navigate disputes effectively and recognise when a will may not stand as written.
