UKMy parent's will was changed while they were vulnerable. Can I contest it?
Yes, you may contest the will if your parent lacked mental capacity, was unduly influenced, or the will failed to meet formal requirements under the Wills Act 1837.
What the Law Says
The validity of a will in England and Wales depends on strict legal requirements — especially regarding mental capacity, freedom from coercion, and correct execution.
Under the Wills Act 1837, a will must be made by a person aged 18 or over who has testamentary capacity — meaning they understand the nature of making a will, the extent of their property, and the claims to which they ought to give effect.
Section 9 sets out the formal requirements: the will must be in writing, signed by the testator (or by someone else in their presence and by their direction), and the signature must be made or acknowledged by the testator in the presence of two or more witnesses present at the same time — who then sign the will in the testator’s presence.
If your parent was vulnerable due to illness, dementia, or manipulation at the time of signing, the will may be invalid on grounds of lack of capacity, undue influence, fraud, or failure to comply with s. 9 formalities.
Statutory TextNo will shall be valid unless it is in writing and executed in accordance with the provisions of this section.
— Wills Act 1837, s. 9 — Execution of wills
What to Do
Gather evidence of your parent’s mental state at the time (e.g., medical records, witness statements, prior wills)
Check whether the will complies with s. 9 formalities — signatures, witnesses, date, and proper execution
Act quickly: if you intend to challenge after a grant of probate has been issued, you generally have only 6 months from the date of the grant to issue a claim under the Inheritance (Provision for Family and Dependants) Act 1975 — though other challenges (e.g., validity) may be brought later if justified
Seek specialist legal advice before filing — contested will cases are fact-sensitive and require expert assessment
Sources
Not legal advice. This article is general information based on publicly available sources, written for educational purposes. Laws change and individual situations vary. Consult a licensed attorney in your jurisdiction before acting on anything you read here. Last reviewed: 2026-06-08.