Documents to download

The Nationality and Borders Bill (2021-22) sets out reforms to immigration and asylum policy. It would allow new approaches to the process of assessing the age of asylum seekers. This briefing is an overview of current age assessment processes used in the UK and internationally. It outlines some biological methods that could be considered to inform age assessments under the new legislation and provides an overview of the evidence on their validity and limitations. It also considers the wider ethical issues arising from their use and other stakeholder perspectives.

Age assessments are used in the asylum system to determine whether an asylum seeker is under 18 years old. They are needed where an individual’s age is unknown or disputed, and where there is little or no supporting evidence. Common approaches using such methods elsewhere in Europe include analysis of the skeleton or teeth (or both). However these techniques have limitations, and their use in this context is widely criticised by a range of stakeholders. 

Key points in this briefing

  • Age assessments are carried out when an individual’s age is unknown or disputed. One of their uses is to distinguish children from adults in the asylum system. 
  • In the absence of documentary evidence, current policy determines an individual’s age by an initial visual assessment of physical appearance. Where doubt remains, age is assessed by examining social and biographical data. 
  • New legislation allowing for unspecified scientific methods in age assessments is intended to minimise subjectivity.  
  • Biological methods to estimate age are used in asylum policy and processing in other countries. Common techniques involve examining the skeleton and teeth, with but these can be imprecise, with wide margins of error. 
  • Many stakeholders believe that these methods should not be relied upon or replace holistic assessments that draw on a wide range of relevant data.


POSTnotes are based on literature reviews and interviews with a range of stakeholders and are externally peer reviewed. POST would like to thank interviewees and peer reviewers for kindly giving up their time during the preparation of this briefing, including:

  • Members of the POST Board*
  • Sarah Atkins, University of Portsmouth*
  • British Dental Association*
  • Professor Noel Cameron, University of Loughborough*
  • Professor Tim Cole, UCL Great Ormond Street Institute of Child Health*
  • Coram Children’s Legal Centre
  • Dr Roxanna Dehaghani, University of Cardiff
  • Judith Dennis, Refugee Council*
  • Kamena Dorling, Helen Bamber Foundation*
  • Luke Geoghegan, British Association of Social Workers*
  • Ben Greening, Migration Watch UK*
  • Home Office*
  • Dr David Horton, British Society of Paediatric Radiology*
  • Dr Ching-Yu Huang, University of Keele*
  • Dr Riccardo Marioni, University of Edinburgh*
  • Professor Graham Roberts, King’s College London
  • Jo Schofield, Immigration Social Work Services*
  • Professor Helen Stalford, University of Liverpool*
  • Professor Denise Syndercombe Court, King’s College London
  • Dr Sarah Watkins, University of Bristol*

*denotes people and organisations who acted as external reviewers of the briefing.

Documents to download

Related posts