Mental Capacity & Decision Making (UK) – Complete Guide to Rights, Support, Advocacy & Legal Protections
Mental capacity and decision-making can be complex topics. Many people worry that having a disability, learning disability, autism, dementia, brain injury, mental health condition, communication difficulty, or long-term illness automatically means they cannot make decisions. This is not the case.
This guide explains:
- The Mental Capacity Act
- Mental capacity assessments
- Supported decision-making
- Best interests decisions
- Lasting Power of Attorney (LPA)
- Deputyship
- Advocacy rights
- Consent and healthcare decisions
- Financial decisions
- Family involvement
- Complaints and disputes
- Accessible support and information
This guide applies mainly to England and Wales. Scotland and Northern Ireland have different legal frameworks.
Key Principle: Capacity Is Presumed
Under the Mental Capacity Act 2005, every adult is presumed to have capacity unless it is established otherwise.
Having a disability, diagnosis, or health condition does not automatically remove decision-making rights.
Official guidance:
The Five Principles of the Mental Capacity Act
1. Presumption of Capacity
Assume a person can make their own decisions unless proven otherwise.
2. Support Before Deciding Lack of Capacity
Practical support should be provided first.
Examples:
- Easy Read information
- Visual aids
- Interpreters
- Communication support
- Additional time
3. Unwise Decisions Are Allowed
Someone can make a decision others disagree with and still have capacity.
4. Best Interests
If someone lacks capacity for a specific decision, decisions must be made in their best interests.
5. Least Restrictive Option
Any action should interfere as little as possible with the person's rights and freedom.
What Is Mental Capacity?
Mental capacity means being able to make a specific decision at a specific time.
Capacity can vary depending on:
- The decision involved
- Health conditions
- Medication effects
- Stress
- Fatigue
- Communication barriers
- Temporary illness
Capacity Is Decision-Specific
Someone may be able to:
✓ Decide what to eat
✓ Decide where to live
✓ Manage healthcare decisions
But may need support with:
- Complex financial decisions
- Legal matters
- Certain medical decisions
Each decision should be considered separately.
Supported Decision Making
The law requires efforts to help people make their own decisions whenever possible.
Support might include:
- Easy Read information
- Plain English explanations
- Communication aids
- British Sign Language interpreters
- Speech and language support
- Family support
- Advocacy services
- Additional time
Example Request
I would like information provided in a way I can understand so I can make my own decision.
Another Example
I need additional time and communication support before making this decision.
Mental Capacity Assessments
A formal capacity assessment may be carried out if concerns arise about a person's ability to make a particular decision.
The assessor should consider whether the person can:
Understand
Can they understand relevant information?
Retain
Can they retain information long enough to make a decision?
Use or Weigh
Can they consider and weigh information?
Communicate
Can they communicate a decision?
What to Say During an Assessment Example.
Please explain the information in a way that is accessible to me.
I would like support to help me understand the options available.
I would like reasonable adjustments before conclusions are made about my capacity.
Best Interests Decisions
If someone lacks capacity for a specific decision, any decision made on their behalf must be in their best interests.
The decision-maker should consider:
- The person's wishes
- Previous preferences
- Values and beliefs
- Family views
- Professional opinions
- Less restrictive alternatives
What Best Interests Does NOT Mean
Best interests does not simply mean:
❌ What professionals prefer
❌ What family members prefer
❌ What is easiest for services
The person's wishes should still be considered whenever possible.
Example Question
What evidence was used to determine that this decision is in my best interests?
Lasting Power of Attorney (LPA)
A Lasting Power of Attorney allows someone to appoint trusted people to help make decisions if they lose capacity in the future.
There are two types.
Property and Financial Affairs LPA
Can cover:
- Bank accounts
- Bills
- Property
- Benefits
- Investments
Health and Welfare LPA
Can cover:
- Medical treatment
- Care arrangements
- Living arrangements
- Daily care decisions
Official Information
Example Discussion
I would like to create a Lasting Power of Attorney so someone I trust can support me if I become unable to make decisions in the future.
Deputyship
If someone no longer has capacity and there is no LPA, an application may be made to the Court of Protection for a deputy.
Official information:
Deputy Responsibilities
Depending on the order granted, deputies may manage:
- Finances
- Property
- Certain welfare decisions
Deputies must act in the person's best interests.
Court of Protection
The Court of Protection makes decisions regarding:
- Mental capacity disputes
- Deputyship
- Best interests decisions
- Property and financial matters
Information:
Advance Decisions (Living Wills)
Some people choose to record treatment decisions in advance.
An Advance Decision may specify treatments they do not wish to receive in future circumstances.
Information:
Healthcare Decisions & Consent
Healthcare professionals should seek informed consent whenever possible.
Information:
Useful Questions
Can you explain the risks and benefits?
What alternatives are available?
Can this information be provided in an accessible format?
Advocacy Rights
Advocates help people understand decisions and express their wishes.
Advocacy may be especially important when:
- Capacity is questioned
- Best interests decisions are being made
- Healthcare decisions are involved
- Social care assessments are taking place
- There are disagreements with services
Independent Mental Capacity Advocates (IMCAs)
An IMCA may be appointed in certain situations where a person lacks capacity and has no suitable person to represent them.
Information:
- Independent Mental Capacity Advocacy (NHS)
Advocacy Organisations
VoiceAbility
Website:
Telephone:
- 0300 303 1660
POhWER
Website:
Telephone:
- 0300 456 2370
Family Members & Decision Making
Family members can often provide valuable information.
However, family members do not automatically have legal authority to make decisions unless:
- They hold an LPA
- They are a deputy
- They have another legal authority
Example Question
What legal authority is being relied upon for this decision?
Complaints & Challenges
If you disagree with a capacity assessment or best interests decision, you may:
- Request explanations
- Seek advocacy
- Use complaints procedures
- Seek legal advice
- Apply to the Court of Protection in some situations
What to Say
I disagree with this assessment and would like an explanation of how the decision was reached.
I would like my views formally recorded.
I would like information about review and appeal options.
Accessible Information Rights
You can ask for:
- Easy Read
- Large print
- Braille
- Audio information
- British Sign Language support
- Communication support
- Alternative formats
Information:
Useful Organisations
Office of the Public Guardian
Website:
Telephone:
- 0300 456 0300
Citizens Advice
Website:
Advice on:
- Capacity issues
- Benefits
- Legal signposting
- Family matters
Scope
Website:
Helpline:
- 0808 800 3333
Disability Rights UK
Website:
Quick Checklist
✓ Remember that capacity is presumed unless shown otherwise
✓ Ask for support before any conclusions are made about capacity
✓ Request reasonable adjustments
✓ Consider creating a Lasting Power of Attorney
✓ Learn about deputyship if no LPA exists
✓ Ask for accessible information
✓ Use advocacy services where needed
✓ Keep records of decisions and assessments
✓ Challenge decisions if you believe they are incorrect
✓ Ensure your wishes and preferences are recorded
Key Contacts
Office of the Public Guardian
- 0300 456 0300
- Office of the Public Guardian
VoiceAbility
- 0300 303 1660
- VoiceAbility
POhWER
- 0300 456 2370
- POhWER Advocacy
Citizens Advice
Scope
- 0808 800 3333
- Scope
Mental capacity law is designed to protect people's rights, not remove them. The starting point is always that a person can make their own decisions, and support should be provided wherever possible to help them do so.