Testamentary Capacity: What Is Changing

You need mental capacity to make a will

To make a valid will in England and Wales, you must have what the law calls "testamentary capacity" — the mental ability to understand what you are doing and to make meaningful decisions about who gets your property after you die.

This is not an especially high bar. Most adults comfortably clear it. But the legal test for capacity matters a great deal in cases where someone's will is challenged after their death, particularly where the person was elderly, had dementia, or was experiencing cognitive decline. Courts sometimes describe this as the "twilight period" — where someone's mental state falls somewhere between full understanding and obvious incapacity.

The test for whether someone had the capacity to make a will currently comes from a case decided in 1870. In its report Modernising Wills Law (Law Com No 419), the Law Commission recommends replacing that test with the modern framework in the Mental Capacity Act 2005. The draft Bill has not yet been introduced to Parliament, and there is no guarantee it will be enacted. But if it is, this would be one of the most significant changes to will-making law in over 150 years.

The current test: Banks v Goodfellow (1870)

The test that currently governs testamentary capacity was set out by Chief Justice Cockburn in the case of Banks v Goodfellow in 1870. It requires that the person making a will must have the capacity to understand four things:

1. The nature and effect of making a will — they understand they are making a document that will distribute their property after they die.
2. The extent of their estate — they have a broad understanding of what they own.
3. The claims on their estate — they can comprehend who might reasonably expect to benefit from their will (such as a spouse, children, or dependants) and can appreciate the strength of those claims.
4. That no disorder of the mind is distorting their decisions — their understanding must not be impaired by delusions or a disorder of the mind that causes them to dispose of their property in a way they otherwise would not.

This test has served the law for over 150 years. Courts have adapted it over time — for example, recognising that bereavement can amount to a disorder of the mind — and it remains well understood by solicitors and judges. But it has its problems.

Why the Law Commission says this needs reform

The core issue is simple: England and Wales currently has two different legal tests for what is essentially the same question — whether a person has the mental capacity to make a decision about their property.

The Banks v Goodfellow test applies when a solicitor is assessing someone's capacity while preparing their will, and when a court is deciding after someone has died whether their will was valid. But the Mental Capacity Act 2005 (the "MCA") applies when the Court of Protection is deciding whether to make a statutory will on behalf of someone who lacks capacity. Two tests, same question, potentially different answers.

The Law Commission considers this anomalous. As they put it, it is difficult to justify having two different tests governing the same question simply because different people are asking it. In some edge cases, a person might have capacity under one test but not the other. That is unsatisfactory.

Beyond the two-test problem, the Banks test has other drawbacks. Its language is Victorian and can be difficult for non-lawyers to parse. There has been longstanding uncertainty about whether the test has three limbs or four. And while courts have adapted it to reflect modern medical understanding, the test itself has no statutory foundation — it exists entirely in case law, which means its precise boundaries can shift from one High Court decision to the next.

The proposed change: adopting the Mental Capacity Act 2005

The Law Commission recommends that the MCA test should apply to testamentary capacity. This is their Recommendation 1, and it is enacted in the draft Bill through clause 2 (requiring testators to have capacity) and clause 23(3) (providing that references to capacity are to be read in accordance with the MCA).

Under the MCA, a person lacks capacity to make a decision if, at the material time, they are unable to make the decision because of an impairment of, or a disturbance in the functioning of, the mind or brain. A person is unable to make a decision if they cannot understand the relevant information, retain it, use or weigh it as part of the decision-making process, or communicate their decision.

In practical terms, the two tests are broadly similar. The Law Commission acknowledges that in some marginal cases the MCA test could produce different results — it might require slightly more in some respects (such as understanding the reasonably foreseeable consequences of a decision) and slightly less in others. But on balance, the Commission believes that adopting the MCA will make the law simpler, more coherent, and more accessible, while bringing will-making into line with every other area of law where mental capacity is assessed.

The elements of the Banks v Goodfellow test would not disappear entirely. The Law Commission recommends that the MCA Code of Practice should be updated to explain the four Banks limbs as the "relevant information" a person needs to understand in order to have capacity to make a will. The rich case law on Banks would continue to provide practical guidance.

You would be presumed to have capacity

One important consequence of adopting the MCA is that the statutory presumption of capacity in section 1(2) would apply to will-making. That provision states: "a person must be assumed to have capacity unless it is established that he lacks capacity."

Under the current law, there is no equivalent statutory presumption. There is an evidential presumption — if a will is properly executed and appears rational on its face, the court will generally assume the testator had capacity — but it is not set out in legislation. The MCA presumption would put this on a clearer footing.

The Law Commission does not expect this to change the outcome in most contested cases. The modern approach, as the courts have explained, is to assess the totality of the evidence. The presumption would not weaken the duty on solicitors to satisfy themselves that a person has capacity before preparing a will. But it reinforces an important principle: the starting point is that you can make decisions for yourself.

Supported will-making

The MCA also includes a principle that a person is not to be treated as unable to make a decision unless all practicable steps to help them have been taken without success. This principle of supporting people to make their own decisions is relevant to will-making.

The Law Commission considered whether a formal "supported will-making" scheme should be introduced but decided against it. Instead, in a related chapter, the Commission endorses the broader recommendation from its earlier Mental Capacity and Deprivation of Liberty project for a general supported decision-making scheme, and outlines how that could apply to the will-making context. The idea is that people who might otherwise lack capacity could, with the right support, make a valid will that reflects their own wishes.

What is Parker v Felgate, and would it be kept?

There is a longstanding rule in wills law known as the rule in Parker v Felgate (1883). It applies where a person gives instructions for their will to a solicitor while they have capacity, but by the time the will is actually signed, they have lost capacity — perhaps because they have become too ill to fully understand the document.

Under the Parker v Felgate rule, the will can still be valid provided that: the person had capacity when they gave instructions, the will reflects those instructions, the instructions continued to represent their intentions, and at the time of signing, the person understood that they were executing a will based on the instructions they had previously given.

The Law Commission recommends retaining this rule. It provides a practical solution for people whose capacity is declining, and it avoids the cost and delay of obtaining a statutory will from the Court of Protection. A large majority of consultees agreed with this approach.

What does this mean for ordinary people making wills?

For most people, none of this will make any practical difference to the process of making a will. The vast majority of adults have capacity to make a will, and that will remain true regardless of which test applies.

Where the change matters is at the margins — for people experiencing cognitive decline, for families who may one day need to challenge or defend a will, and for the solicitors and medical professionals who assess capacity. For those groups, a single, modern, statutory test is likely to be clearer and easier to apply than the current patchwork of Victorian case law and statute.

It is also worth noting that the draft Bill does not lower or raise the threshold for capacity. The Law Commission describes the change as making the standard "slightly different" rather than higher or lower.

What should you do now?

The draft Wills Bill has not yet been introduced to Parliament. Until it is enacted, the current law — including the Banks v Goodfellow test — applies in full. There is no timetable for when or whether the Bill will become law.

Regardless of which test applies, the practical advice is the same: if you want to make a will, do it while you are well and have no concerns about your capacity. A will made today, properly executed and clearly reflecting your wishes, will be valid under the current law and will remain valid under the new Act if it is passed.

If you have concerns about a relative's capacity, or if you are making a will during a period of illness, it is sensible to have capacity formally assessed by a medical professional at the time the will is prepared. This creates a contemporaneous record that can help defend the will against later challenge.

GetWill's process is designed to be straightforward, but every will we produce is reviewed by a qualified solicitor. That means there is a professional involved who can identify any concerns about capacity and ensure the right steps are taken. If you do not yet have a will, or if your circumstances have changed since you last made one, there is no reason to wait for the law to change.