Challenging a will is legally complex, emotionally difficult, and potentially costly. It should only be pursued where there are genuine legal grounds — not simply because a relative is unhappy with the outcome. This article explains the main grounds on which a will can be challenged, the applicable time limits, and the procedure. For the executor's perspective on administering an estate, see the how to apply for probate article.
Ground 1: Lack of testamentary capacity
A will is invalid if the testator lacked testamentary capacity when it was made. The legal test comes from Banks v Goodfellow (1870): the testator must have understood: (1) the nature of making a will and its effects; (2) the extent of the property being disposed of; (3) the claims of those who might expect to benefit; and (4) must not have been suffering from a disorder of the mind that poisoned their affections or perverted their sense of right. Dementia, serious mental illness, or confusion caused by medication can all potentially give rise to a capacity challenge. The burden of proof is on the person challenging the will once the will itself has been admitted to probate. Expert medical evidence (from the GP, consultant, or an expert on capacity) is essential.
Ground 2: Undue influence
Undue influence in will-making is not the same as commercial undue influence. In probate law, undue influence must be "coercion" — pressure that overpowers the free agency of the testator, not merely persuasion. This is a high bar: an elderly person changing their will in favour of a carer after conversations about their needs is not necessarily undue influence. You would need evidence of threats, isolation, or sustained pressure. Banks and care homes increasingly document that advice was given to the testator to seek independent legal advice, precisely to protect against later challenges.
Ground 3: Fraud or forgery
If the will was forged — the signature is not the testator's — or was obtained by fraudulent misrepresentation, it is void. These are criminal matters as well as civil ones; the police may be involved alongside a civil challenge. Expert handwriting analysis is typically required for forgery claims.
Ground 4: Failure to provide reasonable financial provision (Inheritance Act 1975)
This is the most commonly used route for disappointed beneficiaries. Under the Inheritance (Provision for Family and Dependants) Act 1975, certain categories of person can apply to court for provision from the estate even if the will makes no provision for them or inadequate provision. The eligible applicants include: a spouse or civil partner; a former spouse who has not remarried; a child; a person treated as a child of the family; and a person who was financially dependent on the deceased immediately before their death. The court asks: does the will (or intestacy) make "reasonable financial provision" for the applicant? The answer depends on the relationship and the applicant's needs. Time limit: six months from the date of the grant of probate. This is a strict limit — the court has very limited discretion to extend it. Act quickly. For how the grant is obtained, see the probate article.
Procedure: contentious probate
If you want to challenge the validity of the will itself (capacity, undue influence, fraud), enter a "caveat" at the Probate Registry before a grant is issued. A caveat prevents any grant of probate being issued without the caveator's involvement, giving you time to gather evidence and negotiate. If the dispute cannot be resolved, the matter proceeds as contentious probate litigation in the Business and Property Courts or the Family Division. These cases are expensive — legal costs regularly exceed the value of smaller estates. Consider the economics carefully. Mediation — even in inheritance disputes — is actively promoted by the courts and can resolve matters much faster and more cheaply than litigation. See the family mediation guide and the executor glossary entry.