Mental Capacity Act 2005

A general guide on how the Mental Capacity Act affects you and how you can plan ahead for when you no longer have the mental capacity to make decisions for yourself. Applies to England and Wales.

Terms you need to know



Advance decision

An advance decision is a statement of instructions about what medical treatment you want to refuse in case you lose the capacity to make these decisions in the future. It is legally binding.

Advance statement

An advance statement is a written document that sets out your preferences (apart from refusals of treatment). It is not legally binding. You can ask a professional to follow this document if you ever lose capacity to make these decisions yourself.


An advocate is a person who can both listen to you and speak for you in times of need. Having an advocate can be helpful in situations where you are finding it difficult to make your views known, or to make people listen to them and take them into account. Find out more on our advocacy information page.


An appointee is someone appointed by the Department for Work and Pensions (DWP) to help manage your benefits for you if you lose capacity to manage them yourself.


An attorney is a person over the age of 18 whom you have appointed to make decisions on your behalf about your welfare and/or your property and financial affairs. You need an attorney if you are unable to make such decisions yourself. If you do not have the capacity to appoint an attorney, the Court of Protection may appoint a deputy to perform this role.

  • A health and welfare attorney makes decisions about things like your daily routine, your medical care, where you live and, if you specially request this, whether you should have life-sustaining treatment.
  • A property and financial affairs attorney makes decisions about things like paying bills, collecting benefits and selling your home.

Best interests

Health professionals must act in your best interests before taking certain steps that affect your care and treatment.

The Mental Capacity Act has a best interests checklist, which outlines what health professionals need to consider before taking an action or decision for you while you lack capacity.


'Capacity' means the ability to understand information and make decisions about your life. Sometimes it can also mean the ability to communicate decisions about your life.

If you do not understand the information and are unable to make a decision about your care, for example, you are said to lack capacity.

Certificate of capacity

This is a document, signed by a certificate provider, confirming that you understand why you are making a lasting power of attorney, and that no fraud or undue pressure has been used on you to force you to make it. You need to include a certificate of capacity with your forms when naming someone as your attorney.

Clinical Commissioning Groups (CCGs)

Clinical Commissioning Groups are groups of GP practices and other healthcare professionals and bodies that are responsible for commissioning most health and care services for patients. They have replaced Primary Care Trusts (PCTs) in England.

Court of Protection

The Court of Protection makes decisions and appoints deputies to act on your behalf if you are unable to make decisions about your personal health, finance or welfare.

Deprivation of liberty

A deprivation of liberty is where your liberty is taken away from you - that is, you are not free to leave and under continuous supervision and control. The Mental Capacity Act says that the law allows this only in very specific situations.

This may happen to you if you need to go into a care home or hospital to get care or treatment, but you don't have the capacity to make decisions about this yourself. 

Deprivation of liberty safeguards (DoLS)

If you are in a hospital or care home, your liberty can normally only be taken away if health professionals use the procedures called the Deprivation of Liberty Safeguards. This protects you from having your liberty taken away without good reason.


A deputy is a person the Court of Protection appoints to make decisions for you once you have lost capacity to make them yourself. A deputy usually makes decisions about finances and property. The court can appoint a deputy to take healthcare and personal care decisions, though this is relatively rare.


A person is detained if they are being kept in hospital under section and are not free to leave.

Enduring power of attorney

Enduring powers of attorney have been replaced by lasting powers of attorney in England and Wales. However, they can still be used if they were made and signed before October 2007.


Independent mental capacity advocate (IMCA)

A specially trained advocate who can help you if you do not have the capacity to make particular decisions. NHS bodies or local authorities must take an IMCA's views into account when making decisions that affect you if you have lost capacity.  

They are normally appointed by the local authority in England, and by local Health Boards or other NHS bodies in Wales. They must be independent people of integrity and good character with appropriate experience and training. 

See our page on IMCAs for more information.

Independent mental health advocate (IMHA)

An IMHA is an advocate specially trained to help you find out your rights under the Mental Health Act 1983 and help you while you are detained or under a section of the MHA. They can listen to what you want and speak for you.

You have a right to an IMHA if you are:

  • detained in hospital under a section of the Mental Health Act. But if you are in England, you cannot have an IMHA if you are under sections 4, 5, 135 and 136.
  • under Mental Health Act guardianship, conditional discharge and community treatment orders (CTOs)
  • discussing having certain treatments, such as electroconvulsive therapy (ECT).

In Wales, voluntary patients and people under short-term sections of the Mental Health Act can also have an IMHA.

For more information see our pages on IMHAs (England) and IMHAs (Wales).

Informal patient or voluntary patient

These are people who are staying in a psychiatric hospital but are not detained under the Mental Health Act. They should be able to come and go from the hospital within reason and are able to discharge themselves if they decide to go home.

Lasting power of attorney (LPA)

A lasting power of attorney is a legal document that lets you appoint someone, called an attorney, to make decisions for you.

Litigation friend

A litigation friend is someone who can take your place in legal proceedings, if you lack capacity to take part yourself. For example, the litigation friend could instruct solicitors on behalf of you, or the litigation friend could speak to the judge directly on your behalf.

A litigation friend could be a family member, a friend, or the Official Solicitor.

Mental Capacity Act 2005 (MCA)

 If you can’t make decisions for yourself because you don’t have the mental capacity to make them, the Mental Capacity Act 2005 tells you:

  • what you can do to plan ahead
  • how you can ask someone else to make decisions for you
  • how you can make decisions for someone else

Mental Capacity Act Code of Practice

An official document that places certain legal duties on health and social care professionals, and offers general guidance and information to anyone caring for someone who may lack capacity. It explains how the Mental Capacity Act should be interpreted.

Mental disorder

When the Mental Health Act talks about someone with mental health problems and whether or not they should be sectioned, it often uses the term “mental disorder”. The Act defines this as “any disorder or disability of mind” (section 1).

Mental disorder can include:

  • any mental health problem normally diagnosed in psychiatry
  • learning disabilities, if the disability makes you act in a way which may seem "abnormally aggressive" or "seriously irresponsible"

Mental Health Act 1983 (MHA)

This is a law that applies to England and Wales which allows people to be detained in hospital (sectioned) if they have a mental illness and need treatment. You can only be kept in hospital if certain conditions are met.

Official solicitor

If you lack capacity to conduct legal proceedings for yourself, and decisions are being made for you in a court, the court may ask the Official Solicitor to take part in the proceedings. The job of the Official Solicitor is to make sure that your interests are protected during the proceedings.

Office of the Public Guardian (OPG)

The Office of the Public Guardian:

  • makes sure decisions made by the Court of Protection are enforced
  • registers lasting powers of attorney
  • supervises deputies appointed by the Court
  • helps attorneys and deputies carry out their duties
  • publishes information and guidance about the Mental Capacity Act for families, carers, healthcare professionals and lawyers
  • publishes forms for making a lasting power of attorney and applying to the Court of Protection 
  • investigates concerns about the actions of attorneys and deputies

Relevant person's representative (RPR)

This is someone who can support you in all matters connected to a deprivation of liberty safeguards situation, like requesting a review of the deprivation of liberty and making an application to the Court of Protection. It can be someone like a family member (and often is). You can choose who you want it to be if you have the capacity to do so.

An relevant person's representative must be:

  • aged 18 or over
  • willing to be your RPR
  • able to keep in touch with you
  • physically well enough so that they can carry out their role
  • an independent person. This means they cannot be your professional or paid carer.

Responsible clinician (RC)

This is the approved clinician in charge of your care and treatment while you are sectioned under the Mental Health Act.

Certain decisions, such as applying for someone who is sectioned to go onto a community treatment order (CTO), can only be taken by the responsible clinician.

All responsible clinicians must be approved clinicians. They do not have to be a doctor, but in practice many of them are.


In this guide, being 'sectioned' means that you are kept in hospital under the Mental Health Act. There are different types of sections, each with different rules to keep you in hospital. The length of time that you can be kept in hospital depends on which section you are detained under.

See our information on sectioning to find out more.


This information was published in November 2017. We will revise it in 2019.

Mental Health A-Z

Information and advice on a huge range of mental health topics

> Read our A-Z


Helping you to better understand and support people with mental health problems

> Find out more

Special offers

Check out our promotional offers on print and digital booklets, for a limited time only

> Visit our shop today