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." The Police and Criminal Evidence Act 1984 section 63B(10) states that in relation to a 'juvenile' (aged 10–16) an appropriate adult should be:
- (a) his parent or guardian or, if he is in the care of a local authority or voluntary organisation, a person representing that authority or organisation; or
- (b) a social worker of a local authority; or
- (c) if no person falling within paragraph (a) or (b) is available, any responsible person aged 18 or over who is not a police officer or a person employed by the police;
Local authority Youth Offending Teams (YOTs) have a statutory duty to provide an appropriate adult for all children under the Crime and Disorder Act 1998 s.38(4)(a). This is carried out whenever parents are unavailable, unwilling, or inappropriate to act as appropriate adult. Depending on the local authority, this may be carried out by YOT staff, sessional workers, community volunteers or contracted out to a specialist charity or business.
The role includes:
- (a) To support, advise and assist the detained person, particularly while they are being questioned.
- (b) To observe whether the police are acting properly, fairly and with respect for the rights of the detained person. And to tell them if you think they are not.
- (c) To assist with communication between the detained person and the police.
- (d) To ensure that the detained person understands their rights and that you
- have a role in protecting their rights.
Appropriate adults are also required whenever mentally vulnerable adults are detained in custody. However, there is no statutory provision for vulnerable adults  and formal schemes are not available in all parts of England and Wales.
Vulnerable defendants in Northern Ireland may also be able to access the services of a Registered Intermediary to facilitate communication while giving oral testimony at court (DoJ, Northern Ireland)
The role of appropriate adult in Scots Law is different from that in England and Wales. Appropriate Adults facilitate communication between the police and adults (people aged 16 or over) who have a mental disorder. This is defined in the Mental Health (Care and Treatment) (Scotland) Act 2003 as: ‘any mental illness, personality disorder, learning disability however caused or manifested’. In practice this includes people with acquired brain injury, autistic spectrum disorder or dementia.
- Pierpoint, Harriet (2008). "'Quickening the PACE? The use of volunteers as appropriate adults in England and Wales'". Policing and Society 18 (4): 397–410. doi:10.1080/10439460802094678.
- UK Home Office. "Home Office Website - PACE Codes". Retrieved 12 February 2014.
- "National Appropriate Adult Network (NAAN) Website - Network Map". Retrieved 12 February 2014.
- UK Home Office. "Guidance for Appropriate Adults". Retrieved 12 February 2014 2011. Check date values in:
- UK Home Office. "Home Office Website - PACE Code C". Retrieved 12 February 2014.
- "National Appropriate Adult Network (NAAN) Website - Who's looking out for the adults?". Retrieved 12 February 2014.