Mental Capacity Act 2005 (the MCA)

These pages are not intended to offer legal advice.

What is the Mental Capacity Act 2005?

The Mental Capacity Act 2005 is a piece of law that explains what to do when a person is not able to make decisions for themselves. The MCA applies to anyone 16 years old, and over, who has a mental impairment that might affect their ability to make decisions. To find out more about the MCA, please go to Learn more about the Mental Capacity Act or go to the Government Legislation website.

Decision Making and Why it Matters

We all have the right to choose how to live our lives. The right to make our own decisions is the basis of the MCA and other laws such as the Human Rights Act 1998. Although the MCA applies to lots of types of decisions, this page is about making health and care decisions. 

Assessing capacity

If there is a good reason to think someone might not be able to make a decision, health or care professionals will assess their capacity. Assessing capacity means checking carefully whether or not a person can make a decision, taking into account what the MCA says.

Making decisions for someone who lacks capacity, in their best interests

When a person is assessed as lacking capacity to make a decision, that decision may need to be made for them, in their best interests. Best Interests isn’t defined in the MCA but deciding what’s in a person’s best interests includes thinking about things like their mental, physical, financial, social, and cultural interests.

You can find out more about best interests by clicking on ‘What is best interests?’ below.

Further information can be accessed on our Court of Protection and Deprivation of Liberty pages.

Page last updated: 10 Oct 2023