asked Her Majesty's Government:What identifying numbering system, if any, is used to record the arrival of immigrants or asylum seekers in the United Kingdom; and whether the numbers so allocated are notified to any other government departments. [HL3230]
Persons subject to control who are seeking leave to enter the United Kingdom are given a unique port reference number if they are required to submit to further examination by an immigration officer. This will include port asylum applicants, who will also attract a separate and individual Home Office reference number. These numbers do not in themselves identify such persons as asylum seekers, and they may be quoted in correspondence with other government departments.