UKCan I make a will if I have dementia?
Yes, you can make a will if you have dementia — but only if you still have 'testamentary capacity' at the time of making it.
What the Law Says
The validity of a will in England and Wales depends not on diagnosis, but on mental capacity at the moment the will is made. The Wills Act 1837 sets out formal requirements, including how a will must be signed and witnessed.
A person with dementia may still have testamentary capacity — meaning they understand the nature of making a will, know the extent of their property, and can appreciate who might reasonably expect to benefit. This standard comes from the 1870 case Banks v Goodfellow (not provided here, so not included), but the Wills Act 1837 governs the formalities.
Under section 9 of the Wills Act 1837, a will is only valid if it is in writing, signed by the testator (or by someone else in their presence and by their direction), and the signature is 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.
Statutory TextNo will shall be valid unless it is in writing and signed by the testator or by some other person in his presence and by his direction; and the signature must be made or acknowledged by him in the presence of two or more witnesses present at the same time; and such witnesses must attest and subscribe the will in the presence of the testator.
— Wills Act 1837, s. 9 — Execution of wills
What to Do
Consult a solicitor experienced in wills and mental capacity — they can assess capacity and document the assessment.
Arrange for the will to be signed in the presence of two independent, adult witnesses who are not beneficiaries.
Keep clear records (e.g., a letter from the solicitor or GP) confirming you understood the will’s contents and effects at the time of signing.
Consider obtaining a medical opinion if your dementia diagnosis is known — this helps prevent future challenges.
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.