Legal Aspects > Capacity Act (2005) - England & Wales

Capacity Act (2005) - England & Wales

5 Statutory Principles


  1. A person must be assumed to have capacity unless it is established that he/she lacks capacity.

  2. A person is not to be treated as unable to make a decision unless all practicable steps to help him/her to do so have been taken without success.

  3. A person is not to be treated as unable to make a decision merely because he/she makes 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 his/ her 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


Capacity is related to a specific decision and if not a global impression of a person’s ability to make any or all decisionsIf patient lacks any of the four criteria then they lack capacity:


  1. The patient understands the information relevant to the decision.

  2. The patient is able to retain that information.

  3. The patient is able to weigh that information as a part of the process of making a decision.

  4. The patient is able to communicate his/her decision (whether by talking, using sign language or any other form of communication).

Capacity decisions can be complex. Symptoms of mental disorder can put physical health at risk; when the patient is treated against their will for a physical health cause this must be done under the capacity act. Treatment of the underlying mental disorder, under the mental health act, may enable them to regain capacity for treatment of their physical health problem.


When both the capacity act and the mental health act can be used, that is criteria are met, mental health act will take precedence as the patient is then provided with the statutory safeguards provided by the act.