The Mental capacity act 2005 provides the legal framework for assessing whether a person has the mental capacity to make decisions and defines how others can make decisions on their behalf if they lack mental capacity. Its scope is wide ranging involving decisions regarding social care, healthcare, and financial matters.

The MCA applies in England and Wales to everyone who works in health and social care and is involved in the care, treatment, or support of people over 16 years of age who may lack capacity to make decisions for themselves. It is based on best practice and creates a single, coherent framework for dealing with mental capacity issues and an improved system for settling disputes, dealing with personal welfare issues and the property and affairs of people who lack capacity. It puts the individual who lacks capacity at the heart of decision making and places a strong emphasis on supporting and enabling the individual to make his/her own decisions. If they are unable to do this, it emphasises that they should be involved in the decision-making process as far as possible. It introduces important new safeguards for people who lack capacity and the people who work with, support or care for them. It is underpinned by five key principles which must inform everything you do when providing care or treatment for a person who lacks capacity.

An independent mental capacity advocate (IMCA) must be instructed for people in the following circumstances.

• The person is aged 16 or over.
• A decision needs to be made about either a long-term change in accommodation or serious medical treatment.
• The person lacks capacity to make that decision, and there is no one independent of services, such as a family member or friend, who is “appropriate to consult”.
• An IMCA may also be provided to people for other decisions concerning Care Reviews or Adult Protection cases.