Adult Social Care Glossary, v 0.6

(3) 'Carer' means an adult who provides or intends to provide care for another adult (an 'adult needing care'); but see subsections (9) and (10).
(9) An adult is not to be regarded as a carer if the adult provides or intends to provide care--
(a) under or by virtue of a contract, or
(b) as voluntary work.
(10) But in a case where the local authority considers that the relationship between the adult needing care and the adult providing or intending to provide care is such that it would be appropriate for the latter to be regarded as a carer, that adult is to be regarded as such (and subsection (9) is therefore to be ignored in that case).