Grounds for Contesting a Will in the UK: The 5 Legal Bases

Ground 1: Lack of Testamentary Capacity

The most commonly pleaded ground. The test for testamentary capacity derives from the Victorian case Banks v Goodfellow (1870): to have capacity, a testator must:

1. Understand the nature of making a will and its effects
2. Understand the extent of the property they are disposing of
3. Comprehend the claims of those who might reasonably expect to benefit (family members)
4. Not be suffering from a disorder of the mind that poisons their affections, perverts their sense of right, or prevents the exercise of their natural faculties

Key points: dementia, Alzheimer's disease, or other cognitive impairments may affect capacity, but having these conditions does not automatically mean capacity was lacking — capacity must be assessed at the time the will was made. A person can have fluctuating capacity (lucid intervals).

Evidence needed: medical records, GP notes, care home records, psychiatric assessments, expert medical opinion (a retrospective capacity assessment by a consultant psychiatrist costs £3,000–£8,000).

For a full guide, see our guide on lack of testamentary capacity.

Ground 2: Lack of Valid Execution

Section 9 of the Wills Act 1837 requires that for a will to be valid:

• The will must be in writing
• The will must be signed by the testator (or by someone else in their presence and at their direction)
• The testator must sign (or acknowledge their signature) in the presence of two witnesses who are both present at the same time
• Each witness must then sign the will in the testator's presence

Common execution failures: only one witness present, witnesses signed on a different occasion, the testator did not actually sign but only initialled, a beneficiary or their spouse witnessed the will (which does not invalidate the will but causes the gift to that beneficiary to lapse).

If the will was prepared by a solicitor, a failure of execution is less likely but does occur. The Golden Rule — that solicitors preparing wills for elderly or ill testators should obtain a medical assessment of capacity — is relevant but not a strict legal requirement.

Ground 3: Undue Influence

Undue influence in will-making means that the deceased was coerced into making the will in a particular way — the influence must have been so strong that it overrode the testator's own free will, such that the resulting will was not truly their own act.

Important points:

• Unlike undue influence in contract law, there is no presumption of undue influence in will cases — it must be actively proved
• The standard of proof is the civil standard (balance of probabilities), but courts recognise the seriousness of the allegation
• Suspicious circumstances (such as a beneficiary accompanying the testator to the solicitor) may support an inference of undue influence but are not conclusive
• Persuasion, pressure, or emotional influence that is within normal family dynamics does not constitute undue influence — it must be coercive

For a full guide, see our guide on undue influence in will-making.

Ground 4: Fraud or Forgery

A will can be challenged if it is:

• Forged: The testator's signature is not genuine — it was written by someone else without the testator's knowledge or authority
• Obtained by fraud: The testator was deceived into signing a will — for example, they were told they were signing a different document

Forgery claims require forensic handwriting evidence, which can be expensive (£3,000–£8,000 for a report from a Questioned Documents Examiner). Fraud claims require clear evidence of the deception.

For a full guide, see our guide on fraud and forgery in wills.

Ground 5: Lack of Knowledge and Approval

Even if the testator had capacity and the will was properly executed, the will can be challenged if it can be shown that the testator did not know and approve the contents of the will at the time they signed it.

This ground is most relevant where:

• The testator was blind or illiterate and the will was read to them — was it read accurately?
• The will was prepared by a beneficiary or someone close to a beneficiary — there is a heightened obligation on the court to scrutinise whether the testator truly knew and approved
• The testator signed without reading the will
• There is evidence the testator was misled about the will's contents

If knowledge and approval are challenged, the burden shifts to the person propounding the will to prove it was known and approved.

What Is Not a Ground for Contesting a Will

To avoid wasted time and costs, it is important to understand that the following are NOT valid grounds for challenging will validity:

• You feel the distribution is unfair or you expected to receive more
• The testator changed their will and left less to you than before
• You do not like the beneficiaries
• The will was made quickly before death without professional advice
• You were close to the deceased and feel you deserved more

If you feel the provision for you was inadequate (but the will is otherwise valid), you may have an Inheritance Act 1975 claim. See our guide on Inheritance Act 1975 claims.

For the immediate step of protecting your position, see our guide on how to enter a caveat. For time limits, see our guide on time limits for contesting a will. For costs, see our guide on costs in contentious probate. For the overall estate administration, see our estate administration checklist.

Get started with Farra for help with the administration side of the estate.