Grounds for contesting a will in the UK: 6 legal reasons

The shock of discovering a loved one’s will does not reflect their true wishes can feel like a second bereavement. While the legal system respects a person’s final wishes, it also recognises that on what grounds can you contest a will matters deeply when something feels fundamentally wrong. Your concerns deserve careful consideration. If you’re facing this difficult situation, speaking with a solicitor who specialises in will disputes should be your first step toward clarity and potential resolution.

Don’t miss this essential guide to protecting your inheritance rights and understanding when challenges can succeed.

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Ground N°1: Lack of valid execution

When considering on what grounds can you contest a will, invalid execution often provides the clearest path forward. The Wills Act 1837 establishes strict formalities that must be followed precisely, not as mere technicalities, but as essential safeguards against fraud and coercion:

• The will must be in writing.
• It must be signed by the testator.
• The testator must sign with the intention of giving effect to the will.
• The signature must be made or acknowledged in the presence of at least two witnesses present at the same time.
• Each witness must then sign the will in the presence of the testator.

Signature placement issues, improper witnessing, and attestation errors frequently undermine otherwise valid wills. If you’ve noticed witnesses signed at different times, or perhaps the testator signed in an unusual location on the document, these could constitute legitimate grounds to contest a will UK.

Ground N°2: Lack of testamentary capacity

Among the most common reasons to contest a will is the claim that the testator lacked mental capacity when creating or updating their will. This ground applies when you believe your loved one didn’t understand what they were doing due to cognitive impairment, mental illness, or medication effects. Capacity issues can arise even when a will appears properly signed and witnessed.

When evaluating mental capacity, UK courts rely on the landmark 1870 case Banks v Goodfellow, which requires that a testator must:

• Understand they are making a will and its effects.
• Know the nature and extent of their property.
• Comprehend who might reasonably expect to benefit from their estate.
• Not be affected by any “disorder of the mind” that influences their decisions about beneficiaries.

This Victorian test remains remarkably resilient in modern courts, namely when contesting a will due to dementia UK. In Simon v Byford (2014), the court confirmed that even someone with early-stage dementia can still make a valid will during “lucid intervals” if they satisfy these four elements.

Ground N°3: Undue influence

Perhaps one of the most challenging grounds to contest a will UK is undue influence, which occurs when someone exerts pressure that overrides the testator’s free will. This isn’t about mere persuasion or suggestion, but actual coercion that essentially replaces the testator’s wishes with someone else’s. This ground often arises when a family member notices a sudden change in the will favouring someone who had special access or control over the testator.

In Hubbard v Scott (2011), the court examined claims of undue influence after a testator left the bulk of his estate to his cleaner, rather than his daughters. While the circumstances raised suspicion, particularly the cleaner’s close involvement in the testator’s daily life and the exclusion of close family, the High Court ultimately did not find undue influence. The judge held that there was insufficient evidence of coercion or manipulation that overpowered the testator’s free will. The ruling confirmed that affection, dependence, or even persuasion is not enough to establish undue influence without clear proof of pressure or domination.

Ground N°4: Fraudulent or forged wills

Fraud allegations represent some of the most serious reasons to contest a will. Unlike capacity or execution issues, fraud claims suggest deliberate deception or criminality. These cases arise when you suspect someone has tampered with the document itself or tricked your loved one into signing something they didn’t understand.

Fraud in the context of wills takes several forms:

• Impersonation of the testator during will execution.
• Forged signatures of either the testator or witnesses.
• Document substitution where pages are replaced after signing.
• Fraudulent misrepresentation about the document’s nature or contents.
• Fraudulent calumny where the testator is poisoned against natural beneficiaries through false statements.

Ground N°5: Lack of knowledge and approval

Even when a will appears properly executed and the testator had basic mental capacity, it may still be invalid if they didn’t truly understand and approve its contents.

This ground becomes relevant in situations such as:

• The testator was blind or physically unable to read the document.
• The testator was illiterate or couldn’t read the language of the will.
• The will dramatically favours someone in a position of trust or control.
• The will contains complex provisions the testator likely didn’t understand.
• Someone else arranged the will’s preparation with minimal testator involvement.

Ground N°6: Claims under the Inheritance Act 1975

Unlike the previous five grounds which challenge a will’s validity, the Inheritance (Provision for Family and Dependants) Act 1975 allows certain individuals to claim reasonable financial provision even from a perfectly valid will. This provides an alternative avenue when on what grounds can you contest a will seems limited by the will’s technical correctness.

The Inheritance Act operates differently from validity challenges:

• It doesn’t invalidate the will but modifies how assets are distributed.
• It’s limited to specific categories of eligible applicants.
• It focuses on financial provision rather than the testator’s intentions.
• Claims must be brought within six months of probate (though extensions are possible).
• Successful claims result in reasonable provision, not necessarily equal inheritance.

Eligible applicants include spouses, civil partners, former spouses who haven’t remarried, children (including adult children), anyone treated as a child of the family, and dependents.

FAQs

• How long does it take to contest a will in the UK? Most will contests take between 12-24 months to resolve.
• Can I contest a will after probate has been granted? Validity challenges have no strict deadline, but act quickly as asset recovery becomes difficult.
• What happens to the estate during a will contest? Estate administration typically pauses for disputed assets. A caveat can prevent probate for six months.

The grounds for contesting a will provide essential pathways when facing inheritance disputes. With strict legal thresholds for each challenge type, success depends on prompt action, systematic evidence gathering, and specialist legal advice.

Concerned about a will’s validity?

Qredible’s network of specialist contentious probate solicitors offers expert guidance through every step of the process.

KEY TAKEAWAYS

• The UK legal system recognizes six primary grounds for contesting wills, including lack of valid execution, testamentary incapacity, undue influence, fraud, lack of knowledge and approval, and claims under the Inheritance Act 1975.
• Timing is critical when challenging wills, with some claims facing strict deadlines, particularly Inheritance Act claims.
• Professional legal guidance significantly increases your chances of success when pursuing valid grounds to contest a will UK.