Technical note for IORPs
CSSF
1. Purpose and scope
The document provides technical specifications and guidelines for pension funds (IORPs) on how to submit their reporting files to the CSSF (Luxembourg’s financial supervisory authority). It explains file formats, naming conventions, reporting requirements, and validation rules.
2. File format and taxonomy versions
Submissions must use XBRL format, based on EIOPA’s pension fund taxonomies.
The version of the EIOPA taxonomy used must correspond to the reporting reference date (for example, the first report for September 2019 must use EIOPA V2.3).
From January 2025, EIOPA V2.9 PF becomes mandatory for all pension fund reports submitted to the CSSF.
3. Additional CSSF-specific reporting
Beyond EU-mandated reports, the CSSF requires additional reports on a compartment (sub-fund) basis, which also must follow the EIOPA XBRL taxonomy but be submitted for each authorised compartment separately.
4. File naming, accounting and versioning
A strict naming convention applies to zipped IORP reports, detailing fields such as the remitter, fund identifier, compartment code, reporting period, accounting version, finality status, report type, and taxonomy version.
Reports should use the CSSF accounting status ‘L’ (individual reporting, excluding foreign branches) and the CSSF final status ‘N’ (non-audited figures).
5. Data transmission
Reports must be transmitted using the CSSF’s external transmission channels under the “Canaux externes historiques” system, ensuring proper file transport and data protection.
6. XBRL instance requirements
Each XBRL instance must cover a single IORP or sub-fund, a single reporting period, a single currency unit, a single audit status, and a single consolidation status.
Partial or “update” filings are not allowed — each submission must be complete, and any new file fully replaces previous ones.
Submissions must comply with the XBRL Filing Rules defined by EIOPA, unless CSSF-specific deviations are stated.
IORPs must identify themselves using their LEI (Legal Entity Identifier) in XBRL filings. For compartment-level reports, using the CSSF identifier is permitted when an LEI is not used.
7. Validation rules and deactivations
EIOPA periodically publishes validation rules for their taxonomies. The CSSF applies these “deactivated” rules in their validation system; a list of deactivated rule sets is maintained and updated on the CSSF website.