Self-disclosure from the Central Register of Foreign Nationals

An application for self-disclosure from the Central Register of Foreign Nationals must be submitted in writing to the Federal Office of Administration (BVA) in Cologne. To prevent personal data from being disclosed to unauthorized persons, a request for information can only be answered substantively once the identity of the person concerned has been verified. The required proof of identity is provided abroad by the certification of the signature on the application form.
The signature certification can be performed, for example, by a German diplomatic mission abroad, but also by bodies authorized to certify signatures in Poland (e.g., a notary's office).
Detailed information and the necessary application form in various language versions can be found on the website of the Federal Office of Administration: Information from the Central Register of Foreign Nationals
Information on signature certification at German diplomatic missions in Poland can be found here: Signature Certification.

Self-disclosure from the Schengen Information System

A request for self-disclosure from the Schengen Information System must be submitted in writing to the Federal Criminal Police Office (BKA) in Wiesbaden. Since the information may only be provided to the person actually authorized to receive it, the BKA must verify the identity of the person requesting the information and ensure that only that person receives the information.
Further information and the necessary application form in various language versions can be found on the website of the Federal Criminal Police Office: Provision of information on data stored in the Schengen Information System