The Mental Capacity Act (2005)

The Mental Capacity Act (MCA) is a law that protects the rights of people aged 16 and over. It enables them to make their own decisions wherever possible.

It also adds a safety net for those who are unable to make a specific decision due to a mental disorder.

This can be decisions about:

  • minor things like what food to buy or what to wear
  • more serious things like whether to move to a care home or have major surgery
Decisions for a person aged 16 or 17 cannot automatically be made by their parents or guardians.

Find out more about the MCA and making decisions on these websites:

The 5 key principles

The MCA has 5 key principles that everyone must follow. These are:

  1. A person must be assumed to have capacity unless it is established that they lack capacity.
  2.  A person is not to be treated as unable to make a decision unless all practicable steps to help them to do so have been taken without success.
  3. A person is not to be treated as unable to make a decision merely because they make an unwise decision.
  4. An act done, or decision made, under this Act for or on behalf of a person who lacks capacity must be done or made, in their best interests.
  5. Before the act is done, or the decision is made, regard must be had to whether the purpose for which it is needed can be as effectively achieved in a way that is less restrictive of the person’s rights and freedom of action.

Assessing capacity

Anyone can assess capacity. Some more complex decisions may need a trained professional to do this, such as a doctor or social worker.

For a person to make a decision, they need to be able to:

  • understand the information relevant to the decision
  • remember the information long enough to make a decision
  • work out what they think about it. This includes weighing up the advantages, disadvantages and likely consequences
  • communicate their decision to others

A person has a lack of capacity to make a particular decision if they are unable to do:

  • one or more of the 4 steps above
  • this due to a mental disorder such as (but not limited to) dementia, a brain injury or a learning disability

Best interest decisions

If someone is unable to make a specific decision, then the decision will need to be made in their best interests.

Sometimes, a person will have:

  • made a Lasting Power of Attorney
  • made an Advance Decision
  • a Court Appointed Deputy who can make the decision on their behalf

Anyone who makes a best interest decision must abide by the law and follow the Code of Practice.

The person must still be involved in the decision, even if they lack capacity. Their wishes and feelings should be taken into account.

Others involved in the person's life should also be spoken with. They should be given the opportunity to share their views. That includes:

  • family members
  • friends
  • carers
  • other professionals
  • their advocate (if relevant)

If a best interest decision cannot be reached, an application may be made to the Court of Protection. This means a judge will make the final decision.

No one can make decisions on another person's behalf about consent to sex or marriage.


Advocacy helps a person to speak up and get involved when decisions are being made about their life. It means having someone on your side.

If you're aged 16 to 17:
Find information about how advocacy can help you on the Council for Disabled Children website.

If you're a parent of a young person with special educational needs or a disability (SEND): 
Find information about how advocacy can help you as a parent of a young person with SEND on the Council for Disabled Children website.

If you're aged 18 or over:
Find out how Dorset Advocacy may be able to help you.

Deprivation of Liberty Safeguards (DoLS)

Some people are prevented from leaving care in hospitals and care homes for their own safety. This is called 'deprivation of liberty'.

A person may be 'deprived of their liberty' if they:

  • lack capacity to consent to their care and treatment
  • are under continuous supervision and control
  • are not free to leave a care home or hospital

Deprivations of liberty are judged on a case by case basis.

If a person is deprived of their liberty, it is important that the person has legal protection to ensure:

  • that their human rights are not breached
  • there is a way for them to challenge this deprivation of liberty through court

This legal protection is called the Deprivation of Liberty Safeguards (known as DoLS).

If a care home or hospital is depriving a person of their liberty, then they must tell us. We will check to see whether they are acting lawfully.

The deprivation of liberty has to be in the person's best interests. It must be both necessary and proportionate to the likelihood and seriousness of harm they could face if they left on their own.

We need to complete an assessment to authorise the deprivation. We do this once we are told that a person is being, or is likely to be, deprived of their liberty.

This assessment is carried out by 2 professionals:

  • a specially trained doctor that will assess the person's mental disorder
  • a second professional called the Best Interest Assessor (BIA)

The BIA is a specially trained:

  • social worker
  • nurse
  • occupational therapist
  • psychologist

They will spend time talking to the person and anyone involved in their life, such as:

  • carers
  • family members
  • other professionals

A DoLS Standard Authorisation is only granted once the doctor and BIA are satisfied that the deprivation of liberty is lawful.

During the DoLS assessment, a representative for the person must be selected. They are known as the Relevant Person's Representative (RPR). The RPR keeps in touch with the person and supports them to challenge the DoLS Standard Authorisation if they object to:

  • their care
  • their accommodation
  • restrictions in their life
There are rules about who can be appointed as an RPR.

If the person or their RPR disagrees with the standard authorisation, then they can challenge us in the Court of Protection. This is called a Section 21A challenge. There is non-means tested legal aid available along with full advocacy support for this process.

A judge will then decide:

  • what care and treatment is in that person's best interests
  • where they should stay

The DoLS process only applies to those in a hospital or care home. If a person is deprived of their liberty in their own home or a supported living environment, then we will apply to the Court of Protection for a judge to agree this. This is often known as a "Community Deprivation of Liberty" or referred to as the "Re. X procedure".

Changes to the law

Parliament amended The Mental Capacity Act in 2019. The changes are yet to come into effect in England and Wales.

A new system called Liberty Protection Safeguards (LPS) will replace DoLS. It will ensure those deprived of their liberty have their human rights protected.

There was recently a public consultation on the new draft Code of Practice. We are waiting for the Government to publish their findings, which is likely to be in the early part of 2023.

We will update this page as we know more, but for now, the existing DoLS process remains active.

Find out more about the Liberty Protection Safeguards and what these mean for individuals, carers and professionals.

What we do

For our MCA Team, maximising a person’s human rights and autonomy is at the heart of everything we do. Our task is to ensure that every citizen of Dorset who receives care, gets this support following the principles of the Mental Capacity Act (2005).

To achieve our task, our MCA team has four functions:

  1. To provide expert advice and guidance to professionals and care staff working in Dorset on MCA issues.
  2. To provide bespoke training to Dorset Council staff, and staff within partner organisations including the independent and voluntary sector, on MCA best practice.
  3. To coordinate and oversee the provision of Deprivation of Liberty Safeguards (DoLS) authorisations for Dorset citizens.
  4. To plan ahead for the implementation of Liberty Protection Safeguards (LPS).

Contact details

Mental Capacity Act (MCA) Team

Name: Sue Farmer – Specialist Manager, Tilly Baden – Assistant Team Manager
Tel: 01305 225650 (Monday to Thursday 9am to 5pm and Friday 9am to 4pm)
Full contact details