Circular on Mandatory Adoption of XBRL-CSV Format for Supervisory Reporting

Circular
Triq l-Imdina, Zone 1 Central Business District, Birkirkara CBD 1010 +356 2144 1155 communications@mfsa.mt www.mfsa.mt Circular to Credit Institutions including Foreign Branches on the Mandatory Adoption of the XBRL-CSV Format for Supervisory Reporting Further to the communication issued on 24 June 2024 regarding the upcoming changes in supervisory reporting requirements driven by the EBA-led transition to the XBRL-CSV reporting format, the MFSA (the “Authority”) is providing an update on the local implementation, including the switchover to the new format for the submission of EBA￾developed regulatory requirement obligations. The Authority will adopt the XBRL-CSV reporting format for the above submissions made via the LH Portal, with mandatory application starting from reports with reference date 31 December 2025. This initiative will be implemented based on the following guiding principles:

1. Simultaneous implementation across all reporting modules: To avoid unnecessary
   complexity and fragmentation, once the new reporting format requirement is in effect, it will apply uniformly to all supervisory reporting modules. This approach avoids the need to support dual formats and ensures consistency across all datasets for both institutions and the Authority.
2. Application of CSV format starting from December 2025 reference date: The XBRL￾CSV format will be applicable only to reports referencing 31 December 2025 and later.
   Reports relating to earlier reference dates, including resubmissions, must continue to be submitted in the current XBRL-XML format. This approach ensures format consistency across original and resubmitted data. Allowing CSV for earlier reference dates would risk introducing conflicting formats for the same reporting period, increasing complexity in validation and data handling.
3. Availability of a pre-production testing environment: To support institutions in adapting
   to the new format, the MFSA will provide access to a dedicated testing environment in Q4 2025, replicating the parameters and validations of the LH portal production system. This environment is intended exclusively for testing the technical processing of XBRL￾15 May 2025

Circular
Triq l-Imdina, Zone 1 Central Business District, Birkirkara CBD 1010 +356 2144 1155 communications@mfsa.mt www.mfsa.mt CSV submissions on the LH portal. Institutions may use it to identify and resolve formatting or structural issues in advance of the mandatory implementation date. It should be noted, however, that this testing is not conducted in parallel with ECB systems, and feedback received through this environment may not reflect accurate outcome of ECB business validations. Accordingly, it should not be used for data quality assessments. Details on the launch and access procedures for the testing environment will be communicated in due course. Institutions are strongly encouraged to use this initiative to ensure readiness.
4. Format validation checks in LH Portal: To safeguard data quality and streamline
processing, the MFSA is adapting the existing first-level automated format checks within the LH Portal. These checks will:

• Validate that the submission format (CSV or XML) corresponds correctly to the
  reference date;
• Immediately reject incorrect file types (e.g. CSV for pre-Dec 2025 ref. date or XML for
  Dec 2025 onwards);
• Additionally, assess compliance with selected technical requirements of the EBA XBRL￾CSV reporting package, particularly as outlined in the ‘File naming structure for
  remittance to the EBA’ section of the EBA Filing Rules v5.5.
  These checks are intended to minimise submission errors and reduce the need for post￾submission correction. Institutions are reminded to undertake all the necessary internal preparations for the switchover to the new reporting format, including resource allocation, system updates and testing. For further information or clarification, please contact the Authority at Bankingdata@mfsa.mt.