Mental Capacity Act 2005 (England and Wales)
UK Parliament
Summary
The Mental Capacity Act provides the legal framework for making decisions on behalf of people aged 16 and over who lack the capacity to make a particular decision themselves. It rests on five principles: assume capacity unless it is established otherwise; take all practicable steps to help the person decide; do not treat someone as lacking capacity just because their decision seems unwise; any decision made for them must be in their best interests; and choose the option that least restricts their rights and freedom. Capacity is decision-specific and time-specific. A person lacks capacity if, because of an impairment or disturbance in the functioning of the mind or brain, they cannot understand the relevant information, retain it long enough, use or weigh it, or communicate their decision. The Act also covers advance decisions to refuse treatment and lasting powers of attorney. Scotland and Northern Ireland have their own legislation.
Why it matters at interview
Capacity underpins almost every consent and refusal scenario. Knowing the functional test — understand, retain, weigh, communicate — lets you reason precisely instead of guessing.
Key takeaways
- Five principles: presume capacity, support decision-making, unwise ≠ incapable, best interests, least restrictive.
- Capacity is specific to a decision at a particular time.
- Functional test: understand, retain, use or weigh, communicate.
- Applies to people aged 16+ in England and Wales.
How to use it
In refusal scenarios, say explicitly: 'First I'd assess whether she has capacity for this decision using the four-part test.'