Age disputes arise in asylum proceedings when the Home Office or a local authority disputes a young person's claimed age. The consequences are significant — an incorrect age assessment can result in a child being detained, denied access to children's services, or treated as an adult throughout their asylum claim. This guide explains the legal framework, the assessment methods, and the role of expert evidence.
The legal framework for age assessment in the UK is primarily judge-made. The Supreme Court in R (A) v London Borough of Croydon [2009] UKSC 8 confirmed that the question of whether a person is a child is a question of fact to be determined by the court, not a matter of administrative discretion. The court held that the Upper Tribunal (Immigration and Asylum Chamber) has jurisdiction to determine age disputes in the context of asylum proceedings, and that local authority age assessments are not determinative.
The Nationality, Immigration and Asylum Act 2022 introduced a new statutory age assessment scheme, creating the National Age Assessment Board (NAAB) and giving the Secretary of State the power to conduct age assessments. The scheme, which came into force in 2023, provides for scientific age assessment methods — including dental X-rays and bone density assessments — to be used alongside holistic assessments. The use of scientific methods remains controversial, and the courts have not yet definitively resolved the weight to be given to radiological evidence in age disputes.
Local authorities conduct Merton-compliant age assessments — so called because of the Administrative Court's judgment in R (B) v London Borough of Merton [2003] EWHC 1689 (Admin), which set out the minimum procedural requirements for a lawful age assessment. A Merton-compliant assessment must be conducted by two trained social workers, must give the young person an opportunity to respond to adverse findings, must consider all available evidence, and must not rely solely on physical appearance.
Expert evidence in age disputes takes two principal forms: holistic psychosocial assessment and medical/radiological assessment. The courts have consistently held that no single method of age assessment is reliable in isolation, and that the best approach combines multiple sources of evidence.
A consultant clinical or forensic psychologist, or a specialist social worker with expertise in age assessment, conducts a holistic assessment of the young person's developmental stage, emotional maturity, and life experience. The assessment considers the young person's account of their history, their educational background, their family circumstances, and their psychological presentation. The expert provides an opinion on the age range that is consistent with the totality of the evidence, expressed as a range rather than a precise figure.
A consultant paediatrician assesses the young person's physical development, including Tanner staging of pubertal development, height, weight, and dental development. The paediatrician provides an opinion on the age range consistent with the physical findings. Paediatric assessment is most useful at the extremes of the age range — where a person is clearly a young child or clearly an adult — and is less reliable in the 15–19 age range where most disputes arise.
Dental X-rays (orthopantomograms) and wrist X-rays (for bone density and epiphyseal fusion) are used to estimate skeletal and dental maturity. The British Dental Association and the Royal College of Paediatrics and Child Health have both expressed reservations about the use of radiological methods for age assessment, noting that the margin of error is too wide to be reliable in the 16–18 age range. The courts have generally treated radiological evidence as one factor among many, rather than as determinative.
Where a local authority has conducted an age assessment that the young person disputes, the challenge is brought by way of judicial review in the Administrative Court or, in asylum proceedings, before the Upper Tribunal. The grounds for challenge include procedural unfairness (failure to comply with Merton requirements), irrationality, and failure to take into account relevant evidence.
Expert evidence is central to the challenge. A psychologist or paediatrician who has assessed the young person and reached a different conclusion from the local authority provides the court with an independent basis for questioning the assessment. The expert's report should address the methodology used by the local authority, identify any procedural or substantive errors, and provide the expert's own opinion on the age range consistent with the evidence.
What is the age range consistent with the physical, psychological, and developmental evidence?
Is the young person's account of their age and history consistent with their presentation?
Are there any factors — such as trauma, malnutrition, or delayed development — that could affect the reliability of physical indicators of age?
Does the local authority's assessment comply with the Merton requirements?
What weight should be given to the radiological evidence, if any?
What is the likely impact on the young person of being treated as an adult if they are in fact a child?
Age assessment experts should be instructed as early as possible — ideally before the local authority's assessment is finalised, so that the expert's findings can be put to the assessing social workers. Where the assessment has already been completed, the expert should be instructed promptly to allow time for the report to be prepared before any judicial review proceedings are issued.
The letter of instruction should provide the expert with the young person's full immigration history, the local authority's age assessment, any supporting documents (school records, medical records, country of origin information), and the specific questions the expert is asked to address. The expert should be asked to provide their opinion in the form of an age range, with the degree of confidence they attach to that range.
The benefit of the doubt principle
Where the evidence is genuinely equivocal, the courts have held that the benefit of the doubt should be given to the young person. An expert who can demonstrate that the evidence is consistent with the claimed age — even if it does not conclusively establish it — provides a basis for the court to apply the benefit of the doubt principle and treat the person as a child.
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