UK migrant age assessment errors intensify debate over biometric age estimation

New Home Office figures raise fresh questions about the reliability of appearance-based age assessments used at the UK border, showing that hundreds of asylum seekers initially classified as adults were later found to be children.

The findings come as the UK considers introducing biometric facial age estimation (FAE) technologies to help determine the age of undocumented migrants. During the six months from July to December 2025, 17 percent of migrants assessed as adults by immigration officials were subsequently determined to be children.

During the six months from July to December 2025, immigration authorities assessed 1,885 individuals as adults. More than half were sent for a full age assessment conducted by health and social workers. Among them, 326 were later assessed to be children (17 percent), while a decision is still pending on the remaining 377 asylum seekers.

The report shows that hundreds of minors are being wrongly routed into the adult asylum system, leaving them unsupervised with strangers or in adult detentions and prisons, according to the Helen Bamber Foundation (HBF). The human rights charity has previously found that children as young as 14 were forced to share rooms with unrelated adults, with no safeguards in place.

Among them are refugees from conflict zones like Afghanistan, Sudan, and Eritrea, who frequently arrive without documents.

“Change is urgently needed to prevent many more children from being harmed,” says the organization’s Director of Policy, Kamena Dorling. Border officials should only dispute a child’s claimed age in exceptional circumstances, she adds.

The UK government has been attempting to incorporate age estimation technology into the asylum process to reduce human error. The UK Home Office closed a £1.3 million (US$1.7 million) tender in October to procure an algorithm that can accurately predict a person’s age without verifiable identity documents.

The plan is facing resistance from civil society. The Helen Bamber Foundation, alongside the British Association of Social Workers and organizations such as Human Rights Watch, argues that the introduction of AI tools could prove dehumanizing and may not provide accurate age estimations.

AI can replicate human biases and fails to account for the physical effects of trauma, malnutrition, and exhaustion brought on by dangerous journeys, notes HBF.

The initiative to introduce biometric age assessment comes as the country continues to struggle with the “small boat” migrant crisis.

The latest Home Office figures show that the number of asylum seekers undergoing age assessments has increased to over 6,000 a year. In comparison, in the decade between 2010 and 2020, authorities conducted only between 300 and 1,200 age assessments a year.

The increase in age assessments reflects the rise in people claiming asylum, which has now reached 111,000 a year, the report notes. In the 12 months from April 2025 to March 2025, 7 percent of asylum claimants underwent an age assessment.

The UK system has three levels of age assessment for migrants: an Initial Age Decision (IAD) conducted by immigration authorities on arrival, which is based solely on physical appearance and demeanor. In case of disputes, the individual is referred to social workers at the Local Authority Age Assessment (LAAA) or the National Age Assessment Board (NAAB).

Article Topics

biometric age estimation  |  biometrics  |  children  |  facial age estimation (FAE)  |  Home Office Biometrics (HOB)  |  immigration  |  UK age verification