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Mental Capacity Act 2005

What is the Mental Capacity Act? 

The Mental Capacity Act (MCA) applies in England and Wales. It is a Legal framework for making decisions on behalf of [people 16+ that cannot make decisions for themselves 
Everyone working with or caring for a person (16+) must comply with this ACT. 

For the purposes of this Act, a person lacks capacity in relation to a matter if at the material time he is unable to make a decision for himself in relation to the matter because of an impairment of, or a disturbance in the functioning of, the mind or brain.’

The ACT providers safeguards both the decision maker and the person. And introduced Lasting Power of Attorney (LPA), Court of Protection (CoP) and Independent Mental Capacity Advocates (IMCA).

This might include, but is not limited to, people with:

  • dementia
  • learning disabilities
  • mental health conditions
  • brain injuries 

The ACT providers safeguards both the decision maker and the person. And introduced Lasting Power of Attorney (LPA), Court of Protection (CoP) and Independent Mental Capacity Advocates (IMCA)

Key principles

The Act is based on five important principles:

  1. Assume capacity: Always start by assuming a person can make their own decisions.
  2. Provide support: Give people the help they need to make decisions before deciding they cannot.
  3. Respect unwise decisions: A person is not lacking capacity just because they make a decision others disagree with.
  4. Act in best interests: Any decision made for someone must be in their best interests.
  5. Choose the least restrictive option: Decisions should be proportionate.  

The following video, from the NHS, details what the five principles are and what they mean. 

How does the Act work?

The Act explains:

  • how to assess if someone can make a decision
  • what to do if they cannot
  • how to make decisions on their behalf

It applies to:

  • everyday decisions
  • important decisions (healthcare, finances, living arrangements)

It also provides:

  • a legal framework for decision-making
  • independent advocates for people with no one to support them 

What is “mental capacity”?

A person lacks capacity if they cannot make a specific decision at the time it needs to be made due to an impairment of or disturbance in the functioning of the mind or brain. 

How is capacity assessed?

A person must be able to:

  • understand the information
  • remember it
  • use or weigh the information in order to make a decision
  • communicate their decision

If they cannot do any one of these, they may lack capacity for that decision. 

Capacity is always:

  • decision-specific
  • time-specific (there are times when a longitudinal assessment may need to be undertaken)

Who assesses capacity?

The person making the decision (the “decision maker”) is usually responsible for assessing capacity. This should be the most relevant person to the decision needing to be made, for example:

  • A health or social care professional
  • A carer or support worker
  • A family member (for day-to-day decisions)

Making decisions in someone’s best interests

If someone lacks capacity, any decision made for them must be in their best interests.

This includes:

  • involving the person as much as possible
  • considering their wishes, feelings, beliefs and values
  • talking to people who know them (family, carers, friends)
  • considering whether they might regain capacity

Decision-makers must also:

  • avoid discrimination
  • choose the least restrictive option
  • balance all relevant information carefully

Additional protections and safeguards

There are important legal safeguards that support people who lack capacity, including:

  • Independent Mental Capacity Advocates (IMCAs): For people with no one else to support them.
  • Lasting Power of Attorney (LPA): This is a formal and legal mechanism that was created and governed under the MCA. LPA is a legal process for someone over 18 years old to appoint a trusted person to hold LPA in order to make decisions on their behalf if they lose capacity. 
  • Court of Protection: Makes decisions when there are disputes or complex cases.
  • Office of the Public Guardian: Oversees attorneys and deputies.
  • Advance decisions to refuse treatment: People can plan ahead and refuse certain medical treatments.
  • Legal protection against wilful neglec or ill-treatment: It is a criminal offence to abuse or neglect someone who lacks capacity. 

Key message

The Mental Capacity Act is about:

  • empowering people to make their own decisions
  • protecting those who cannot
  • ensuring decisions are proportionate and least restrictive

Useful resources

Mental Capacity Act learning events recordings

Access the recordings of each of the Mental Capacity Act presentations. January 2025.

Alcohol Use and the Mental Capacity Act (MCA) video archive

Presentation slides, webinar pre-reading and questions from chat.

Further information

Visit the Swindon Advocacy Movement webpage for more resources on advocacy.