GUIDES
An unwise decision alone does not establish incapacity. The Mental Capacity Act protects the person’s right to decide according to their own values, with practicable support.
Author: Nellie Supports Ltd
Publication Date: 15/05/2026
39 Essex Chambers, Mental Capacity Guidance Note: Carrying out and recording capacity assessments.
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An unwise decision alone does not establish incapacity. The Mental Capacity Act protects the person’s right to decide according to their own values, with practicable support. The sections below explain the evidence, practical steps and limits of the assessment or process.
Section 1(4) of the Mental Capacity Act protects an adult from being treated as unable to decide merely because the decision appears unwise. The assessment examines understanding, retention, use or weighing and communication with support, then any impairment and causal link. Risk may justify proportionate enquiries, but the person does not have to share their family’s or professionals’ values to have capacity.
Section 1 of the Mental Capacity Act 2005 states that a person is not to be treated as unable to make a decision merely because they make an unwise one. Capacitous adults can make choices that family or professionals find risky, eccentric or plainly wrong. Disagreeing with a decision is not a basis for finding that the person lacks capacity.
The principle protects autonomy. If unwise decisions could be treated as evidence of incapacity, anyone making an unconventional choice could be overridden. The law deliberately separates the quality of a decision from the ability to make it, so that the right to self-determination is not lost simply because others would choose differently.
The distinction concerns ability to decide, rather than approval of the result. A person may understand the salient risks and choose to accept them. Incapacity under the Act requires an inability in at least one functional area despite practicable support, caused by an impairment or disturbance of mind or brain. It is not confined to an inability to weigh every risk at all.
Professionals can be drawn into what the courts have called the protection imperative, where a wish to keep someone safe leads to a finding of incapacity that the evidence does not support. A series of unwise decisions may prompt an assessment, but the assessment must still test ability, not simply react to risk.
A pattern of harmful or self-defeating decisions can be a legitimate trigger for assessment, particularly where it is out of character or coincides with a change in cognition. The point is that it triggers a proper assessment of the ability to use or weigh information, rather than itself proving that capacity is absent.
People make decisions based on their own values, beliefs and priorities, which may differ greatly from the assessor's. A decision rooted in long-held values is very different from one driven by a delusion, compulsion or an inability to take in the consequences. The assessor must separate a value-based choice from an impairment-driven one.
Record the decision, salient information and consequences, support tried, and evidence about understanding, retention, use or weighing and communication. If an inability is identified, explain its cause. Do not infer incapacity from a refusal of advice, or infer capacity from a fluent explanation without considering all the relevant abilities.
A defensible assessment explains why a decision is unwise yet capacitous, or why an apparently unwise decision in fact reflects an inability to use or weigh information caused by an impairment. Recording this distinction clearly is essential, because it is exactly the point on which families and courts most often disagree.
An unwise decision is not a lack of capacity. The law protects the right to make choices others would not make. Capacity turns on whether the person can understand and weigh the relevant information, not on whether their decision is sensible. Confusing the two is one of the most common errors in this field.
Not merely because the decision is risky. If the person has capacity for the decision, it is theirs to make. Intervention needs either a lawful basis such as safeguarding where coercion is involved, or a proper finding of incapacity followed by best interests decision-making.
No. Lifestyle, values and eccentricity are protected by the Act. An assessor's job is to test decision-making ability against the relevant information, not to grade the person's choices against convention.
Explore the person’s ability to decide with appropriate information and support, rather than grading the result. Family disagreement alone does not remove the person’s authority to make a decision with capacity. If concerns remain about coercion, exploitation or the lawfulness of what is proposed, obtain the appropriate safeguarding or legal advice separately.
The related pages below explain connected decisions, evidence requirements and legal processes.
Before seeking a report, write down the exact decision, relevant date, reason for concern and intended use. Gather the documents that explain the real options and any communication needs. Check any required form or court direction, agree the scope and total fee, and clarify how missing evidence or further questions will be handled.
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