Published on 23 December 2025
Communiqué

Publication of Circular CSSF 25/903

Amendment of Circular CSSF 24/850 on the practical rules concerning the descriptive report and the self-assessment questionnaire to be submitted on an annual basis by support PFS, as well as the engagement of the réviseurs d’entreprises agréés (approved statutory auditors) of support PFS and practical rules concerning the management letter and the separate report to be drawn up on an annual basis.

The CSSF today published Circular CSSF 25/903 amending Circular CSSF 24/850 relating to support PSFs with respect to the practical rules concerning the descriptive report and the self-assessment questionnaire to be submitted annually, as well as the engagement of the réviseurs d’entreprises agréés (“REA”, approved statutory auditors) of support PFS and, in particular, the practical rules regarding the letter of recommendation and the separate report to be drawn up on an annual basis (the “Circular”).

The purpose of this Circular is to amend the provisions relating to the preparation and annual submission of the descriptive report and its annexes, the documents expected as part of the financial year-end closing (including the letter of recommendation from the approved statutory auditor), the self-assessment questionnaire, and the separate report by support PSFs and their approved statutory auditors.

The amendments introduced concern :

  • The method of transmission of the required documents, which must now be carried out via the CSSF’s eDesk platform;
  • An adaptation of the testing rotation plan, notably providing for a three-year cycle for entities classified as low risk.

New submission process

The CSSF informs the Support PFS that all required documents and questionnaires must be uploaded and completed via the CSSF eDesk platform in the future. The questionnaires can be submitted to the CSSF through the following channels:

  • An online solution via the eDesk procedure for manual input by the Support PFS.
  • The Application Programming Interface (API) solution, based on the use of a structured exchange file (JSON format), to be transmitted to the CSSF via the S3 (“Simple Storage Service”) protocol. This file will then pre-fill the questionnaire available on the CSSF eDesk platform. The Support PFS will also be able to directly update in eDesk the data pre-filled through S3. Manual input of responses directly in the eDesk online form remains possible.

A user guide detailing the procedures for creating an account and authenticating on the eDesk platform is also made available on the eDesk homepage.

The portal for the financial year ending 31 December 2025 should be accessible in the following weeks.

Any question relating to this communication or Circular CSSF 24/850 as amended should be addressed to psfsupport@cssf.lu by copying your usual point of contact at the CSSF.

Any technical questions regarding the communication channels mentioned above should be addressed to eDesk@cssf.lu.