Grounds to contest a will

Last reviewed 18 August 2026

A will is not undone by disappointment alone. The court will set one aside only where one of a handful of established grounds is made out — and the burden of proving it falls on the person who challenges.

The recognised grounds

Lack of testamentary capacity — the person did not understand what they were doing when they made the will, often through illness or dementia. Undue influence — they were coerced, not merely persuaded. Want of knowledge and approval — they did not truly know and approve the contents. Improper execution — the will was not signed and witnessed as the Wills Act 1837 requires. Fraud or forgery — the will, or a signature, is not genuine.

What the court looks for

Capacity cases turn on contemporaneous medical records and the recollection of those present; undue influence is hard to prove because it usually happens behind closed doors, and the court needs more than suspicion. Homemade wills fail on execution more often than professionally drawn ones — a caution in itself.

Sources. Wills Act 1837 (execution); Banks v Goodfellow (capacity test); established case law on undue influence and knowledge and approval.