In English Law, an appropriate adult is a parent, guardian or social worker; or If no person matching this is available, any responsible person over 18. The term was introduced as part of the policing reforms in the Police and Criminal Evidence Act 1984 and applies in England and Wales.

 

In England and Wales, an appropriate adult must be called by police whenever they detain or interview a child (aged 10 to 17) or vulnerable adult.

 

They must be present for a range of police processes, including intimate searches, and identification procedures, as detailed in the Police and Criminal Evidence Act 1984 (PACE) Codes of Practice, primarily Code C.

 

In relation to children, appropriate adult is defined in primary legislation under section 38(4)(a) of the Crime and Disorder Act 1998, which defines the role as being to safeguard the interests of children and young persons detained or questioned by police officers.

 

Source: Wikipedia