The number of individuals who have been age assessed while in detention is not held centrally. Age assessments are carried out by the relevant local authority.
Individuals whose age is disputed will only be considered for detention where:
• there is credible and clear documentary evidence that they are 18 years of age or over
• a full "Merton-compliant" age assessment by a local authority has been carried out and is available stating that they are 18 years of age or over
• their physical appearance/demeanour very strongly suggests that they are significantly over 18 years of age and no other credible evidence exists to the contrary.
Otherwise individuals are treated as children until a full age assessment has been conducted by a local authority and all available evidence has been duly considered. This includes victims or potential victims of human trafficking and the Modern Slavery Act 2015 places a presumption about age on a statutory footing when arrangements to assist a potential victim are being carried out.