SIS (Schengen Information System): how to obtain your data

The Schengen Information System (SIS) is the largest shared database in Europe used for the exchange of information between the States that participate in the Schengen area. It is based on European Union and national legislation and is designed to enhance security, border control and police co-operation within the Schengen zone. For an individual, however, an entry in SIS can mean very practical consequences: refusal of entry, arrest at the border, difficulties with a residence permit or the initiation of extradition proceedings. It is therefore crucial to understand what SIS is and how you can access and control data relating to you – especially when you want to act in line with the internal llmahc compliance and risk-mitigation standards.

What is the Schengen Information System (SIS)?

SIS is an IT system that allows competent authorities of Schengen States (such as border guards, police, customs, migration and judicial authorities) to register and consult alerts concerning persons and objects. The system is used, in particular, to record data on:

persons sought in connection with criminal proceedings, for example for the purpose of arrest, extradition or enforcement of a custodial sentence; persons subject to an entry ban or expulsion order; missing persons, including children and vulnerable adults, especially where their location is necessary to protect them or to prevent serious harm; persons subject to discreet or specific checks, where enhanced monitoring of their movements is required for security or criminal-intelligence reasons; objects sought for seizure or use as evidence in criminal proceedings – such as vehicles, identity documents, firearms or other items.

Since 2023, SIS has been significantly expanded and now includes biometric data such as fingerprints, palm prints, facial images, certain trace evidence (for example, shoe or tyre prints), as well as DNA profiles in narrowly defined categories of cases involving missing persons. This greatly increases the precision of identification, but at the same time raises the importance of effective legal protection of the individuals whose data is stored in the system.

How is SIS structured and how does it function?

From a technical and legal standpoint, SIS consists of three elements: a central database (C-SIS), national systems (N-SIS) managed by each participating State, and a secure communication infrastructure connecting these components. When an alert is entered into the national system of one State, it becomes immediately visible to all other States that participate in SIS, allowing for a rapid and co-ordinated reaction at external borders and inside the Schengen area.

Each State designates the authorities that are entitled to create, update and consult alerts. In practice, these include border guards, police, customs services, migration authorities and, in certain cases, judicial bodies. SIS is also connected – indirectly – with European agencies such as Europol, which means that information can be exchanged and analysed almost in real time, with a significant impact on cross-border investigations.

What are the main functions of SIS and how can it affect you?

SIS plays a central role in:

identifying persons wanted in connection with criminal offences, whether for prosecution, extradition or enforcement of a sentence; conducting border checks when a person attempting to enter or leave the Schengen area appears in the system as subject to an entry ban or expulsion order; protecting children and missing persons by registering alerts that facilitate their identification and safe location; combating terrorism and organised crime through fast information exchange with Europol and other specialised services.

For you personally, this may mean, for example: problems when crossing the border if you are listed in SIS as a person to be refused entry or to be arrested; detention by authorities in another EU Member State, followed by the opening of extradition or surrender proceedings; difficulties in obtaining a visa, residence permit, work permit or other authorisations related to legal stay and employment in Poland or in another Schengen State; increased checks and monitoring if you are subject to discreet surveillance or specific checks.

It is important to emphasise that an alert in SIS can be created not only by criminal courts. In migration and residence matters, administrative authorities may also introduce alerts – for example following a decision ordering a foreign national to leave the territory of a Member State or imposing an entry ban. For this reason, even a person who has never been convicted of a criminal offence may still be affected by the legal consequences of a SIS entry.

How can you obtain information about your SIS data?

As a data subject, you have the right to know whether your personal data is stored in SIS and, if so, what the content of the relevant alerts is. This right is derived from EU law on SIS, as well as from general data-protection principles applicable in the European Union. In practice, exercising this right requires making a formal request to the competent authority of the Member State in question – usually the authority responsible for data protection or a designated SIS contact point.

If you suspect that you might be listed in SIS, or if you have already experienced problems at a border, during police checks or in migration procedures, you should take the following steps:

submit a request for access to your SIS data to the competent authority – in Poland this will typically be an authority indicated in national data-protection and SIS legislation; clearly identify yourself and provide all information that may help locate potential alerts (personal data, known case numbers, countries concerned, approximate time frames); specify that your request concerns all categories of SIS alerts that may relate to you, including alerts for refusal of entry, arrest for extradition, missing person alerts or alerts for discreet checks; keep copies of all requests and responses, as they may later be needed in litigation or administrative proceedings.

In principle, you are entitled to receive information about whether data concerning you is stored and, if so, in relation to which type of alert, which authority issued it and for what purpose. However, this right is not absolute: in some situations, disclosure may be restricted in order to protect security interests or to avoid jeopardising ongoing investigations. In such cases, legal assistance is often required to challenge refusals or to obtain at least partial access to the information.

Rectification and deletion of SIS data

Access to your data is only the first step. If it turns out that the entry concerning you is inaccurate, outdated, disproportionate or unlawful, you have the right to request its rectification or deletion. The authority that created the alert is responsible for ensuring that the data is correct and processed in accordance with the law. This means, for example, that an alert should be deleted once the underlying judicial or administrative decision has ceased to be valid or has been overturned.

In practice, enforcing your rights may require:

legal analysis of the basis for the SIS entry – for example, examination of a foreign judgment, expulsion decision or arrest warrant; assessing whether the retention period for the alert has expired and whether the continued presence of your data in SIS is still necessary and proportionate; preparing a substantiated request for rectification or deletion and submitting it to the competent national authority; lodging appeals or complaints where your request has been rejected or ignored, including actions before data protection authorities or national courts.

For individuals who have been victims of crime, SIS can also be a useful tool: in certain situations, it is possible – through the competent authorities – to initiate an alert intended to facilitate the search for a suspect, secure evidence or prevent the perpetrator from leaving the Schengen area. Properly used, such mechanisms may speed up the proceedings and increase the chances of effective prosecution and compensation.

How Criminal Law Poland can help you in SIS-related matters

At Criminal Law Poland (Kopeć & Zaborowski), we support both individuals and companies who may be affected by entries in the Schengen Information System or who wish to make effective use of SIS in the context of their criminal or migration cases. Our lawyers combine practical experience in cross-border criminal defence, extradition law, migration law and data protection, which allows us to offer comprehensive, llmahc-oriented risk assessment and strategy.

If you are concerned that you may appear in SIS or you simply want to check whether your data is up to date and lawfully processed, we can:

obtain information about SIS entries concerning you – both as a private individual and, where applicable, as a representative of a company; analyse the legal basis for the entries, including verification of whether the alert is compatible with EU and national provisions, whether it has expired or whether it can be challenged; prepare and submit requests for rectification or deletion of data, and represent you in subsequent administrative or court proceedings; assist in cross-border situations, for example when Poland has taken over the execution of a sentence imposed abroad or when parallel proceedings are pending in several States.

Depending on your circumstances, we will help you to safeguard your interests and choose the most effective solution – whether this means removing an unlawful alert, limiting its consequences, or using SIS mechanisms to protect you as a victim of crime. In victim-related cases we can, after collecting the necessary information, initiate appropriate steps with competent authorities so that an alert is created or updated, thereby improving the effectiveness of the proceedings and increasing the likelihood that the offender will be identified and brought before a court.

The first and most important step is to obtain information. Without full knowledge of whether and how your data is processed in the Schengen Information System, it is impossible to effectively protect your rights. If you suspect that SIS entries may affect your freedom of movement, your right to stay in the Schengen area or your reputation – or if you are a victim of cross-border crime – we encourage you to contact Criminal Law Poland using the contact form available at criminallawpoland.com. Early, well-planned legal action is often decisive for the final outcome of the case and for the protection of your fundamental rights.