Circular CSSF 25/903 is a CSSF circular, published 23 December 2025. Subject: Update 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.
\nRelevant for: Support PFS.
\nKeywords: Approved statutory auditor (réviseur d'entreprises agréé), Cabinet de révision agréé, Cybersecurity, eDesk, Information and communications technology (ICT), Information security, Internal governance, Operational risk, Outsourcing, Risk management.
\nAmends Circular CSSF 24/850.
\nIn case of discrepancies between the French and the English texts, the French text shall prevail.
\nCircular CSSF 25/903 Update of Circular CSSF 24/850 Practical rules concerning the descriptive report and the selfassessment questionnaire to be submitted on an annual basis by support PFS 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
\nIn case of discrepancies between the French and the English texts, the French text shall prevail.
\nCircular CSSF 25/903 Update of Circular CSSF 24/850 Practical rules concerning the descriptive report and the selfassessment questionnaire to be submitted on an annual basis by support PFS 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 To all support PFS
\nLuxembourg, 23 December 2025 Ladies and Gentlemen, 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 required as part of the accounting year-end process (including the management letter from the approved statutory auditor), the self-assessment questionnaire, and the separate report prepared by support PFSs and their réviseur d’entreprises agréés (approved statutory auditors, “REAs”). The amendments concern:
\nThe method of transmission of the required documents, which must now be carried out via the CSSF eDesk platform;
\nAn adjustment to the test rotation plan, providing in particular for a three-year cycle for entities classified as low risk.
\nA “tracked changes” version of Circular CSSF 24/850 is available in Annex to this circular.
\nAnnex
\nPractical rules concerning the descriptive report and the selfassessment questionnaire to be submitted on an annual basis by support PFS 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
\nIn case of discrepancies between the French and the English texts, the French text shall prevail.
\nPractical rules concerning the descriptive report and the selfassessment questionnaire to be submitted on an annual basis by support PFS 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 To all support PFS
\nLuxembourg, 19 January 2024 Ladies and Gentlemen, The purpose of this circular is to define the practical rules concerning the preparation and annual submission of the below-mentioned documents by support PFS and their réviseurs d'entreprises agréés (approved statutory auditors, “REA”). More specifically, this circular introduces, on the one hand, a self-assessment questionnaire to be completed on an annual basis by support PFS (“self-assessment questionnaire”) and to be submitted to the CSSF as a replacement of the risk assessment report (“RAR”) required under Circular CSSF 12/5441. The self-assessment questionnaire represents the result of an in-depth review of the objective and content of the information the CSSF requests to receive on the support PFS’ selfassessment and management of the risks to that it may expose the financial sector.
\nThe text above is the opening of the document; the PDF carries the whole.
\nDocument page, PDF. Source: Commission de Surveillance du Secteur Financier (CSSF), reproduced with the CSSF's consent. The French text prevails.
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