(UK) — British officials recorded 4,320 initial age decisions by immigration staff between July 2025 and March 2026, while local councils carried out 3,102 social work assessments and the National Age Assessment Board completed 288, according to new official data that has sharpened attention on how the asylum system decides whether a claimant is a child or an adult.

That question shapes almost every part of an asylum case. A person treated as a child can be referred to a local authority for care, placed through children’s services, assigned a social worker, and given access to education and child-safeguarding protections. A person treated as an adult can be sent to adult asylum accommodation and handled under adult immigration rules.

The stakes are immediate for unaccompanied young people who arrive without reliable identity papers. A disputed date of birth can decide where a young person sleeps, who supervises them, what legal protections apply, and whether officials treat them as a child in need or as an adult asylum seeker.

In the year ending March 2026, around 6,400 people were age assessed for the first time. Of those with an outcome, 43% were found to be adults. The figures show that age disputes are not a side issue in the asylum system, but a recurring part of frontline decision-making.

Home Office guidance allows immigration staff to treat a person claiming to be under 18 as an adult only where two Home Office staff members independently decide that the person’s physical appearance and demeanour very strongly suggest they are significantly over 18. Where doubt remains, the case should usually go to a council for a fuller assessment.

Those fuller assessments are commonly described as Merton-compliant, a term drawn from UK case law. They are meant to be holistic rather than visual checks, taking account of interviews, background, development, family history, education, travel, documents, behaviour, and other evidence.

The National Age Assessment Board, or NAAB, adds a third route. It is a Home Office decision-making function that primarily consists of social workers and can carry out assessments after a referral from the Home Office, a local authority, or a Health and Social Care Trust in Northern Ireland.

That leaves several points where a claimant’s stated age can be tested: an initial Home Office decision, a council assessment, and in some cases a NAAB assessment. Each route carries different methods, safeguards, and practical consequences.

The sharpest concern in the latest figures is the gap between first decisions by immigration officials and later findings by councils. Initial decisions produced a much lower proportion of children than completed local authority assessments, with councils more likely to conclude that a young person was under 18.

Official data also showed that among people deemed to be adults at their first age assessment in July to December 2025, 17% were later found to be children. That means some people first directed into the adult system were later moved back into child protections.

Age assessments sit at the fault line between immigration control and child protection. If a child is wrongly treated as an adult, that person can end up housed with unrelated adults, outside children’s services, missing education and without the welfare support normally attached to a child’s claim. If an adult is wrongly treated as a child, councils and care settings face safeguarding risks and added pressure.

The first error is the more serious one in child-protection terms. A real child can be placed in an adult environment before a full assessment is completed.

Differences between immigration staff and social workers are rooted in how the decisions are made. Border or first-contact judgments often happen under pressure, with limited time, incomplete information, language barriers, exhaustion, trauma, and missing or inconsistent documents.

Appearance alone can mislead. Stress, poor sleep, malnutrition, illness, facial hair, clothing, cultural expectations, and the physical strain of travel can all affect how old someone looks at first encounter.

Social workers usually have more time and a wider brief. Their assessments consider maturity, behaviour, education, family background, consistency of account, and whether adult-like conduct reflects survival experience rather than adulthood.

Neither side gets every case right. The data suggests, however, that quick decisions carry a higher risk of error, especially when a claimant is close to 18 or arrives without documents that officials consider reliable.

That problem is acute for children who have crossed several countries before reaching Britain. Documents may be missing, destroyed, stolen, recorded late, translated differently, or never issued at all. A lack of papers does not end the question, but it often triggers more scrutiny.

Young people whose age is challenged often need to preserve whatever evidence they can gather. Examples that may help establish age include birth certificates, school records, identity cards, family documents, vaccination records, religious records, messages from relatives, photographs, records from refugee agencies, and documents from countries crossed during the journey.

Early legal support also matters. A claimed child placed in adult accommodation may need urgent representations about safety and housing, while advisers may seek records of the initial decision, the reasons for it, interpreter details, and notes about appearance or demeanour before asking for a council assessment or challenging the decision.

Health issues and trauma can complicate the picture. Indicators of trafficking, interrupted education, disability, family separation, and mental health problems may affect both the age dispute and the wider asylum claim.

Families, sponsors, charities, and community groups can influence these cases in practical ways. They may help trace relatives abroad, recover school or medical records, explain naming customs or calendar differences, and connect a young person to legal help.

Those groups may also spot warning signs that a child has been placed in the wrong setting. Red flags include a young person saying they are under 18 but being housed with adults, no social worker involvement, lack of access to education, fear of adults in shared accommodation, worsening mental health, or confusion about review rights.

Councils remain central because they bear much of the immediate burden when age decisions are disputed. If more initial Home Office findings are challenged or reversed, local authorities may face heavier demand for assessments, emergency accommodation, foster placements, and legal work.

Any expansion of the NAAB role would also require clearer working arrangements between councils and the Home Office. Referral routes, the effect of NAAB decisions, and the handling of disagreements all carry practical consequences for who takes responsibility for a young person on any given day.

Cooperation matters because delay creates its own risks. Weak information-sharing can produce wrongful placements, repeated assessments, prolonged uncertainty, and litigation that drains staff time on both sides.

The British government has also explored scientific and technological methods of estimating age, including facial age estimation and other techniques. Those methods are controversial and a tool producing a range may still struggle with the legal question that matters most: whether someone is just under or just over 18.

Biological development varies by sex, ethnicity, nutrition, health, stress, and environment. Technology may assist in some cases, but it cannot remove uncertainty and should not replace a child-sensitive assessment.

Public confidence depends on both sides of the system working at once. Adults should not enter children’s care settings on false claims, yet child-protection law requires caution before safeguards are removed from a person who may still be a minor.

That leaves age assessments as one of the most consequential decisions made at the edge of the asylum process. A difference of one year, from 17 to 18, can alter a person’s accommodation, education, support, legal handling, and exposure to risk.

The latest figures do not show a routine paperwork exercise. They show a process in which initial immigration decisions and fuller social work assessments often reach different answers, and in which some people first classed as adults are later recognised as children.

For unaccompanied young people, that can mean the difference between entering a child-protection system and being left to cope in the adult asylum estate. For a local authority, it can mean another urgent placement, another assessment, and another decision with lasting consequences.

Britain’s asylum system can check age claims and protect children at the same time, but the figures suggest that speed alone does not settle the issue. The test is whether the process can make fair decisions, correct mistakes quickly, and keep children out of adult settings while those decisions are still in doubt.