Watch-list matching of passenger data

What passenger data is matched against

Paragraph 13 of resolution 2396 says member states shall develop watch lists or databases of known and suspected terrorists, including foreign terrorist fighters ¹. Paragraph 16 calls on states to make regular use of INTERPOL databases to screen travellers at air, land and sea ports of entry ¹.

The INTERPOL Stolen and Lost Travel Documents (SLTD) database holds records of travel and identity documents reported stolen, lost, revoked, invalid or stolen blank ². Only the issuing country can add a record. Officials reach it through I-24/7, INTERPOL's police communication system ². Through I-Checkit, trusted private partners such as airlines can submit travel documents for screening at booking, and hits are relayed to law enforcement ².

The UN Security Council Consolidated List covers all individuals and entities subject to Security Council measures ³. Entries carry names, aliases, dates and places of birth, nationality and passport and identity numbers where known ³.

How the check runs

• European Union: the Passenger Information Unit may compare PNR data against relevant databases and against pre-determined criteria ⁴.
• United States: under Secure Flight, airlines collect full name, sex, date of birth and any Redress Number and send them to TSA ⁶. TSA checks them against the No Fly and Selectee components of the Terrorist Screening Database ⁶. An airline may not issue a boarding pass until TSA returns a result ⁶.
• Kenya: an immigration officer may compare API and PNR data against databases of persons or objects sought or on watch lists, for a specified offence ⁹. If a traveller needs further examination, the officer gives a control agency access to the data ⁹.
• United Kingdom: carriers must seek authority to carry passengers through the Government's border system. Refusal grounds include a direct threat to security, an exclusion or deportation order and an invalid travel document ¹⁰.

False matches and human review

Article 6(5) of the EU PNR Directive says any positive match from automated processing must be individually reviewed by non-automated means ⁴. Article 7(6) bars decisions with adverse legal effects based solely on automated processing of PNR data ⁴. Criteria may not be based on race, ethnic origin, religion, political opinions, health or sexual orientation ⁴.

On 21 June 2022 the EU Court of Justice ruled in case C-817/19, Ligue des droits humains ⁵. It noted the fairly substantial number of false positives in 2018 and 2019 ⁵. It said the system's fitness depends on proper checking of positive results by PIU staff ⁵. The databases used must be non-discriminatory and limited to persons or objects sought or under alert ⁵. The Court ruled out self-learning artificial intelligence systems ⁵.

INTERPOL says a person who tries to travel with a document reported lost or stolen faces denied entry or boarding and seizure of the document ².

Redress for travellers

Retention after a match

Under the EU PNR Directive, data is kept five years after transfer and names, contact details and payment data are masked after six months ⁴. The Court of Justice said keeping all passengers' data for six months is in principle within what is strictly necessary, but a general five-year period for all passengers is not ⁵. After six months, it said, retention must rest on objective evidence of risk, such as a verified positive match ⁵.