SIS II (Schengen Information System II)

The EU's largest information-sharing database for border control and police cooperation across Schengen and EU member states. Stores alerts on persons (wanted persons, missing persons, third-country nationals refused entry, border-check subjects) and objects (stolen vehicles, lost / stolen documents, firearms). Border officials, police, immigration officers, and consulates can issue and consult alerts. SIS II is the operational backbone of Schengen border control beyond the EES day-counting and VIS visa-history checks; an SIS hit triggers detention, refusal of entry, or other action depending on the alert type. SIS II Recast operational from March 2023.