Luxembourg Financial Regulatory News:
With this article, we aim to provide a comprehensive overview of the monthly reporting obligation known as the “U1.1 reporting,” as mandated by the Commission de Surveillance du Secteur Financier (CSSF) in Luxembourg through Circular CSSF 15/627. The primary purpose of this U1.1 reporting is to supply the CSSF with data for its statistical analysis and supervisory functions.
The U1.1 reporting in Luxembourg is mandatory for all Luxembourg-domiciled Undertakings for Collective Investment (UCIs), including UCITS, Part II UCIs, Specialised Investment Funds (SIFs), and Investment Companies in Risk Capital (SICARs).
Key changes introduced by this circular include an expanded scope to cover SICARs, a significant enhancement of required financial data – particularly at the individual share class level – and a transition to the Extensible Markup Language (XML) format for submissions. The reporting deadline is strictly set at 10 calendar days after each month-end. A new version of the reporting Annex, which details the specific data items, will become applicable from 1 December 2025.
The official link for this communication related to “Reporting U1.1 – Availability of the new XSD schema” is https://www.cssf.lu/en/2025/09/reporting-u1-1-availability-of-the-new-xsd-schema/
1. Introduction and Purpose of the U1.1 Reporting
Circular CSSF 15/627 implements a new, mandatory monthly reporting framework for Luxembourg investment funds. This U1.1 reporting replaces the previous monthly financial reporting required under LMI Circular 97/136 and CSSF Circular 07/310 (specifically, “table O 1.1”).
The information collected is used directly by the CSSF for two main purposes:
• Statistical Analysis: To gather and analyze data on the Luxembourg fund industry.
• Supervisory Oversight: To monitor the activities and financial health of the funds under its supervision.
The legal basis for this data collection is established in the core laws governing the different types of funds: Article 147 of the UCI law, Article 58 of the SIF law, and Article 32 of the SICAR law.
2. Scope and Affected Entities
The U1.1 reporting in Luxembourg requirement applies to a broad range of Luxembourg-domiciled investment funds. Compliance is mandatory for the following entities:
• UCITS (Undertakings for Collective Investment in Transferable Securities) subject to the Law of 17 December 2010.
• Part II UCIs subject to the Law of 17 December 2010.
• SIFs (Specialised Investment Funds) subject to the Law of 13 February 2007.
• SICARs (Investment Companies in Risk Capital) subject to the Law of 15 June 2004.
A significant change introduced by this circular is the extension of the monthly reporting obligation to include SICARs.
3. Key Changes and Enhancements
The U1.1 reporting in Luxembourg modernizes and deepens the data collection process compared to previous requirements. The main changes are:
• Enhanced Financial Data: Under Circular CSSF 15/627, the reporting requires more detailed information. It includes all data previously reported but is supplemented with new information on the fund’s operational results and extensive financial details for each individual unit/share class.
• New Reporting Format: All U 1.1 reports must be submitted in Extensible Markup Language (XML) format. The CSSF provides a technical guidance document and the necessary XSD schema on its website to facilitate this.
• Introduction of “Reporting Status”: Each report must be classified with one of three statuses:
◦ Final: The data is complete and definitive.
◦ Provisional: The data is temporary and may be updated later.
◦ Null Report: No data to report for the period.
• Collection of Functional Data: The report now serves as a communication channel for key operational data, requiring information on the launch and closing dates of both the fund and its individual share classes.
4. Reporting Principles and Deadlines under Circular CSSF 15/627
To ensure compliance, funds must adhere to the following key principles and instructions:
| Principle | Requirement |
| Reference Date | The report must be based on data as of the last day of every month. |
| Reporting Deadline | The report must be submitted to the CSSF within 10 calendar days after the month-end. |
| Reporting Currency | All financial figures must be expressed in the fund’s official base currency, as stated in its constitutive and offering documents. |
| Umbrella Funds | For umbrella structures, a separate U 1.1 report must be created and submitted for each individual sub-fund. No consolidated report at the entity level is required. |
| First Report | A fund’s reporting obligation begins in the same month it receives its authorization from the CSSF. |
| Submission Method | Reports must be submitted electronically through one of the channels officially accepted by the CSSF. |
| Upcoming Changes | A new version of the reporting Annex, which specifies all required data points, will be applicable from 1 December 2025. |
5. Overview of Required Data Points
The Annex to Circular CSSF 15/627 provides a comprehensive list of all required information. The data is structured into six main sections, covering general, financial, and operational details at both the fund and share class levels.
| Section | Data Category | Key Information Required |
| 1. General Report Information | Report and Sender Details | Reference month, reporting status (Final/Provisional/Null), CSSF code of the sender, and contact details of the employee responsible. |
| 2. General Fund (UCI) Information | Fund Identification & Characteristics | CSSF code and name (for the entity and sub-fund), base currency, Legal Entity Identifier (LEI), valuation date, net asset calculation frequency, launch/closing dates, and redemption frequency. |
| 3. Fund-Level Financial Data | Overall Financials (in Fund Base Currency) | Total net asset value for the current and previous month, total proceeds from shares issued (subscriptions), total payments for shares redeemed (redemptions), and total distributions made during the month. |
| 4. Share Class General Information | Share Class Identification & Characteristics (Per Class) | CSSF code, ISIN code, and name of the share class. Base currency, launch/closing dates, investor base, and whether the class uses specific instruments for FX, interest rates, or other purposes. |
| 5. Share Class Financial Data | Granular Financials (Per Class) | Number of shares outstanding, NAV per share (in both fund and class currency), net return per share, proceeds from issued shares, payments for redeemed shares, total distributions, and income/expenses allocated to the class. |
| 6. Detailed Income & Expenses | Breakdown of Results (in Fund Base Currency) | Income: Dividends (from shares and UCIs), interest (from bonds, loans, bank accounts), rental income, commission income. <br> Expenses: Advisory/management fees, depositary fees, administration fees, audit fees, distribution fees, subscription tax, performance fees, interest paid, and other operational expenses. <br> Profits/Losses: Net realised and unrealised profit or loss on investments and foreign exchange. |
This news related to CSSF – U1.1 reporting in Luxembourg and Circular CSSF 15/627 can be considered beneficial under CSSF-Circulars, IFMs (AIFMs, ManCos) News, Must Read, Undertakings for collective investment (UCIs).
The pre-filled example templates for many CSSF Circulars should be available at https://ratiofy.lu/templates/ from Christmas 2025.
