MCA 2005 s7
Payment for necessary goods and services
7.—(1) If necessary goods or services are supplied to a person who lacks capacity to contract for the supply, he must pay a reasonable price for them.
(2) "Necessary" means suitable to a person's condition in life and to his actual requirements at the time when the goods or services are supplied.
The Mental Capacity Act 2005 has been fully in force since 1 October 2007. For details of proposed amendments, see Mental Health Act 2007.