TITLE: Luxembourg's Financial Authority Amends Residential Real Estate Lending Reporting Requirements
BODY:
On March 25, 2026, the Commission de Surveillance du Secteur Financier (CSSF) published Circular CSSF 26/908, which amends Circular CSSF 18/703 on semi-annual reporting of borrower-related residential real estate indicators. The circular applies immediately to all lenders active in Luxembourg's residential real estate sector.
The amendments primarily address the treatment of rental income in borrower income calculations, update regulatory references, and revise reporting processes and submission channels. The circular specifies that lenders must report residential real estate data semi-annually in April and October each year, with reference dates of 31 December and 30 June respectively. The scope covers loans for purchasing residential real estate in Luxembourg secured by real estate collateral located in Luxembourg, including owner-occupied housing, buy-to-let properties, and renovation loans.
Key reporting indicators include loan-to-value (LTV), loan service-to-income (LSTI), debt service-to-income (DSTI), loan-to-income (LTI), and debt-to-income (DTI) ratios. The circular provides detailed guidance on calculating these variables, including treatment of property valuations, income sources, and debt obligations. Notably, rental income must be determined from available bank information, with best estimates and documented methodology where precise data is unavailable.
Starting from 2024, lenders may submit data via the eDesk portal or through an application programming interface (API) solution using structured exchange files in JSON format via the S3 protocol. Reports for end-December data must be submitted by 15 April each year, while end-June reports are due by 15 October. Lenders should direct technical queries to edesk@cssf.lu and macroprudential policy questions to macropru@cssf.lu.