In practice, this means that upon arrival in the UK asylum seekers will have their fingerprints checked against an EU database known as
Eurodac. The database allows immigration officials to see if an asylum seeker has launched an application in any other EU countries, or come into contact with the authorities there, and determine which country should process their claim.
There are some cases in which this rule doesn’t apply.
For example, if an applicant for asylum has a family member who has already successfully claimed asylum in another EU country, then that country is where their claim should be reviewed. There are a number of further exceptions, including if the applicant is a
minor, if
several family members claim asylum around the same time, or of the applicant is
dependent on the assistance of a parent or family member legally resident in the EU.