CSSF Table B 2.4 Reporting: Participations and Subordinated Loans

CSSF Table B 2.4 reporting changed shape in November 2025. The CSSF reissued the instructions for the table that records a Luxembourg credit institution’s participating interests and subordinated loans line by line, and the reporting workbook now carries columns and portfolio breakdowns that were not in the earlier version. For the 31 December 2025 reference date, the first filing under the new template, the transmission deadline was 11 March 2026 instead of the usual 11 February.

It is a national return outside the standardised EU reporting framework. The Reporting Handbook still cites Circular CSSF 18/686 for B 2.4, while the current B 2.4 form and instructions were updated on 17 November 2025. Since the December 2024 reference date it has been an annual return rather than a quarterly one, so most institutions now touch it once a year.

Related reading: our FINREP reporting guide

What Table B 2.4 Is and Its Legal Basis in Circular CSSF 18/686

Table B 2.4 records the detail of a credit institution’s participating interests and subordinated loans, including debt instruments. It is one of the reporting tables the CSSF introduced that are not covered by the common European reporting, and Circular CSSF 14/593 confirms that these national tables remain applicable alongside the FINREP and COREP returns. Circular CSSF 18/686 remains the circular cited by the CSSF Reporting Handbook for B 2.4, while the current technical instructions and layout were updated on 17 November 2025. The handbook records a first-application date of 1 January 2008.

The table is split into two sub-tables. Table B 2.4 A covers participating interests. Table B 2.4 B covers subordinated loans, including debt instruments. Both are prepared under IAS/IFRS accounting standards and expressed in the currency of the credit institution’s capital.

The instructions anchor the definition of a participating interest in the Law of 5 April 1993 on the financial sector, as amended, and in the CRR (Regulation (EU) No 575/2013). For B 2.4 A a participation means either holding rights in the capital of an undertaking, whether or not represented by certificates, that create a durable link and are intended to contribute to the undertaking’s activity, or directly or indirectly holding at least 20 percent of the voting rights or capital of an undertaking. That 20 percent limb matters because it can pull a holding into the table even where the bank would not describe it internally as a strategic stake.

The placement of B 2.4 functions as a bridge return, one that gives the CSSF a named, line-by-line view of the holdings and subordinated claims that the own funds calculation deducts or risk-weights, and ties those items back to specific portfolios of the FINREP balance sheet.

Who Must Report B 2.4 and the Branch Versions That Trip Filers Up

The obligation falls on credit institutions incorporated under Luxembourg law and on certain branches operating in Luxembourg. The version a bank produces depends on whether it runs foreign branches.

A Luxembourg-law credit institution with branches abroad prepares B 2.4 in two distinct accounting versions: a version L for the Luxembourg head office alone, and a version N for the global institution including its branches. On top of that, the head office prepares a version S for each individual branch, carrying that branch’s figures separately. A Luxembourg-law credit institution with no foreign branches files a single version L. Branches established in Luxembourg by non-EU (third-country) credit institutions also file a single version L.

The instructions do not separately address branches established in Luxembourg by EU-origin credit institutions for this table, so a branch in that position should confirm its filing status with the CSSF rather than assume the treatment that applies to the FINREP tables.

The branch endowment capital is where version L and version S have to agree. The dotation capital that the Luxembourg head office makes available to a foreign branch is recorded on the asset side of the head office situation, so it appears in B 2.4 version L. The matching amount shows up in the branch’s own situation, version S, at FINREP line F 01.03: 010 “Capital”. A break between those two figures points to a branch that was mapped on one side of the ledger but not the other.

Alongside the accounting versions L, N and S, the CSSF Reporting Handbook separately uses a Preliminary/Final version code. For B 2.4 specifically, the applicable rows state that a Preliminary (N) version is to be provided; they do not list a Final (D) B 2.4 submission. Read the sibling CSSF tables B 2.5 B and B 2.5 E for the same version logic applied to staff expenses and tax detail.

What the B 2.4 Report Contains: Two Sub-Tables Tied to FINREP F 01.01

Every line in B 2.4 traces to a portfolio of table F 01.01, the FINREP balance sheet assets statement. It disaggregates balances the bank has already booked, one row per individual holding.

Table B 2.4 A: participating interests

Part A reports the participations held as equity instruments in four F 01.01 portfolios: non-trading financial assets mandatorily at fair value through profit or loss (line 097), financial assets at fair value through other comprehensive income (line 142), investments in subsidiaries, joint ventures and associates (item 260), and non-current assets and disposal groups classified as held for sale (item 370). Each participation gets its own row.

Part A carries ten columns. Column 1 is the carrying amount, the figure recognised under those F 01.01 lines on an IFRS basis, reflecting later value changes. Column 2 is cost, the gross acquisition value before any subsequent value change. Columns 3 and 4 record the percentage of investment in the undertaking’s capital and the percentage of voting rights. Column 5 is the amount deducted from own funds, drawn from column 1, for participations in credit institutions, financial institutions or insurance undertakings. Column 6 is the year of entry, the year of acquisition in four digits, using the first tranche where a stake was built up over time. Column 7 is the country of residence of the target as a two-letter ISO 3166 code. Column 8 identifies whether the target is a financial sector entity within the meaning of CRR Article 4(1)(27). Column 9 identifies whether the holding is an important investment in a financial sector entity under CRR Article 43. Column 10 records the prudential consolidation method where the participation is within the CRR consolidation scope. The published French instructions prescribe ESF/NA for column 8, II/INI/NA for column 9, and IG/IP/ME/AM/NC for column 10.

Table B 2.4 B: subordinated loans

Part B reports subordinated loans, including debt instruments, held in a wider set of F 01.01 portfolios: financial assets held for trading, non-trading assets mandatorily at fair value through profit or loss, assets designated at fair value through profit or loss, assets at fair value through other comprehensive income, financial assets at amortised cost, and non-current assets held for sale. Each subordinated loan is a separate row.

Part B carries six columns: the carrying amount, the amount deducted from own funds, the maturity date as a four-digit year (or NA for a perpetual instrument), the country of residence of the borrower, the financial sector entity flag, and the important investment flag. For a perpetual subordinated instrument, the instructions require the maturity field to be reported as NA rather than as a four-digit maturity year.

Reference Dates, Frequency and the Deadlines That Govern B 2.4

The single most important change to grasp is the frequency. The CSSF’s reporting requirements manual records B 2.4 as quarterly through the September 2024 reference date and annual from the December 2024 reference date. The report is now filed once a year on the 31 December reference date and transmitted by 11 February of the following year. That yearly cadence is confirmed by the CSSF’s own summary of the return.

The current dates that matter:

• Reference date for the annual filing: 31 December.
• Standard transmission deadline: 11 February following the reference date.
• Reference date of 31 December 2025: due 11 March 2026, a one-off extension noted in the instructions.
• First application date of the table: 1 January 2008.
• Accounting reference framework: IAS/IFRS. Reporting currency: the currency of the institution’s capital.

The instructions retain the quarter-end reference-date convention (31 March, 30 June, 30 September, 31 December) and list the full four-slot deadline calendar of 12 May, 11 August, 11 November and 11 February. For an annual filing at 31 December, the operative slot is the 11 February date. The instructions state the one-off deadline extension without giving a reason. A team that reads only the periodicity line in the instructions and schedules four quarterly submissions would produce three returns the CSSF no longer expects.

Submission Format and Channel: The Reporting Handbook Schedule of Conditions

From 1 February 2026, the CSSF collects B 2.4 reports exclusively through either the dedicated eDesk procedure or an API solution based on submission of a structured exchange file via S3. The Excel layout published by the CSSF is for illustrative purposes only and is not the submission vehicle. B 2.4 remains a national reporting domain rather than a common European FINREP or COREP module, so its submission requirements should be taken from the dedicated CSSF procedure. For the transmission channels used across CSSF prudential returns more broadly, see how the CSSF structures prudential reporting for payment, e-money and crypto-asset firms.

The CSSF publishes an illustrative Excel layout for B 2.4, while the actual filing is made through the dedicated eDesk or S3 procedure. Any nil-position workflow should therefore follow the fields required by that current procedure.

Validation Points for B 2.4

The B 2.4 instructions specify field definitions and relationships to the relevant F 01.01 portfolios. The checks below should therefore be treated as reporting controls derived from those instructions rather than as a published list of B 2.4 rejection rules.

Column 1 in part A corresponds to the amounts recognised under lines 097 and 142 and items 260 and 370 of F 01.01. Column 1 in part B corresponds to the trading, fair-value, amortised-cost and held-for-sale portfolios identified in the instructions. Those amounts should therefore be reconciled to the corresponding F 01.01 portfolios.

The deduction column is populated from column 1 for the amount that must be deducted from own funds under the applicable CRR requirements. The current CSSF instructions refer in particular to CRR Articles 36 to 49, 56 to 60, 66 to 70, 72 sexies to 72 undecies, 74 to 76 and 89 to 91; Articles 15bis to 15decies and 17 to 19 of Commission Delegated Regulation (EU) No 241/2014; and Articles 9 and 10 of CSSF Regulation No 18-03. The applicable treatment depends on the instrument and issuer classification. This column should therefore be reconciled to the institution’s own-funds reporting, with any difference investigated against the applicable CRR deduction treatment.

Coded fields must use the values specified by the current CSSF instructions and template. Country is reported using a two-letter ISO 3166 code, years use four digits, and the financial-sector-entity, important-investment and prudential-consolidation fields use the prescribed classifications.

Caveats and Interactions: Indirect Holdings, the Double N and Own Funds

Indirect participations sit outside the workbook. The November 2025 instructions state that information on indirect participations is to be sent separately to the CSSF at each closing date, with the CSSF specifying the information to be provided. Those same instructions still state quarterly B 2.4 periodicity, whereas the current Reporting Handbook and CSSF reporting page state that B 2.4 is annual from the December 2024 reference date. The public sources reviewed do not resolve the frequency of the separate-letter requirement after that change, so institutions should confirm that point with the CSSF.

The letter N is used in two different coding dimensions. As an accounting-version code, N identifies the global institution including its foreign branches, alongside L for the Luxembourg head office and S for each branch. Separately, the handbook uses N as the Preliminary version code. For B 2.4, the applicable rows require the Preliminary (N) version and do not list a Final (D) submission, so the accounting-version N and preliminary-version N must be kept distinct without assuming a separate final B 2.4 filing.

Subordinated loans deduct from the lender’s own funds only in a narrow case. The instructions state that a subordinated loan is deducted from the lending institution’s own funds only to the extent it is included in the borrower’s Additional Tier 1, Tier 2, or eligible liabilities. A holding of a borrower’s senior subordinated debt that does not qualify as a regulatory own funds or eligible-liabilities instrument does not drive a deduction, even though it is still reported in part B.

Recent and Upcoming Changes: The November 2025 Format

The November 2025 update is the reason this return is worth a fresh look. The reissued template flags a set of columns and portfolio rows as new. In part A, the new columns are the year of entry, country of residence, the financial sector entity flag, the important investment flag, and the consolidation method, and two new portfolio rows appear for investments in subsidiaries, joint ventures and associates, and for non-current assets held for sale. In part B, the new columns are the maturity date, country of residence, financial sector entity flag and important investment flag, and a new row appears for non-current assets held for sale.

Those additions change what a mapping has to produce. A bank that previously exported carrying amount, cost and percentages now has to source residence, issuer classification against the CRR financial-sector-entity and important-investment tests, and, for participations inside the prudential scope, the consolidation method. The classification columns in particular require the CRR view of each counterparty, going beyond what a standard accounting export supplies.

The move from quarterly to annual filing, effective from the December 2024 reference date, compounds the format change. An institution builds the new extract once a year. The 31 December 2025 reference date was the first filing on the new template and was due on 11 March 2026. The next standard filing is for the 31 December 2026 reference date, due on 11 February 2027.

Frequently Asked Questions

Does a bank with no participating interests still submit Table B 2.4?

The public CSSF material reviewed does not set out a separate nil-return procedure for B 2.4. Because the published Excel layout is illustrative only and filing is made through the dedicated eDesk procedure or API, an institution with no reportable positions should follow the current eDesk procedure or obtain CSSF confirmation on the required treatment.

Do the new November 2025 columns apply to the December 2025 filing?

Yes. The 31 December 2025 reference date is the first filing under the updated template. The CSSF instructions set a one-off deadline of 11 March 2026 for that reference date; they do not state the reason for the extension. The residence, issuer-classification and consolidation columns have to be populated from that reference date onward.

How is version N different from a preliminary version?

They are different axes. Accounting version N covers the global institution including its foreign branches, alongside version L for the head office and version S for each branch. Separately, the handbook uses N as the Preliminary version code. For B 2.4, the handbook requires the Preliminary (N) version and does not list a Final (D) submission.

Where does an indirectly held participation get reported?

The November 2025 instructions state that indirect-participation information is to be sent separately to the CSSF at each closing date. Because those instructions still contain quarterly periodicity while the current Reporting Handbook makes B 2.4 annual, the post-2024 frequency of that separate letter should be confirmed with the CSSF. The table carries one row per directly held participation drawn from the named F 01.01 portfolios.

When does a subordinated loan in part B reduce the lender’s own funds?

Only where the loan is included in the borrower’s Additional Tier 1, Tier 2 or eligible liabilities. A subordinated exposure that does not form part of the borrower’s regulatory own funds or eligible-liabilities instruments is still reported in part B but does not generate a deduction in the amount-deducted column.

How is Table B 2.4 submitted?

From 1 February 2026, the CSSF collects B 2.4 through a dedicated eDesk procedure or through an API solution based on submission of a structured exchange file via S3. The published Excel layout is illustrative only. B 2.4 is a national reporting domain, so the dedicated CSSF procedure governs its submission.

Related Articles

• FINREP Reporting Explained: how the F 01.01 balance sheet and the wider FINREP framework fit together for Luxembourg banks.
• CSSF Tables B 2.5 B and B 2.5 E: the sibling CSSF national returns on staff expenses and detail on taxes.
• COREP Reporting Explained: how own funds and the CRR deductions that the B 2.4 figures feed into are reported.
• ESPREP, STT and IRRBB Reporting in Luxembourg: other CSSF-specific prudential returns filed alongside the accounting schema.
• CSSF Prudential Reporting for PI, EMI and CASP: how CSSF prudential returns are structured and transmitted for non-bank institutions.

Key Takeaways

• Table B 2.4 is a CSSF national return, cited in the Reporting Handbook under Circular CSSF 18/686, reporting participating interests (part A) and subordinated loans (part B) line by line under IAS/IFRS; instructions and layout updated 17 November 2025.
• The return is annual from the December 2024 reference date: file on the 31 December reference date, transmit by 11 February.
• The 31 December 2025 reference date, the first under the November 2025 template, was due 11 March 2026.
• The November 2025 format adds residence, financial-sector-entity, important-investment, maturity and consolidation-method columns, plus new held-for-sale and subsidiaries portfolio rows: remap before filing.
• A Luxembourg-law bank with foreign branches files versions L, N and S; a bank with no foreign branches and a non-EU third-country branch in Luxembourg file version L.
• Carrying amounts must tie to the named F 01.01 lines, and the amount deducted from own funds must be a subset of the carrying amount, consistent with COREP.
• Indirectly held participations are reported separately to the CSSF rather than inside the workbook; the applicable frequency should be confirmed because the November 2025 instructions and the current annual B 2.4 periodicity are not fully aligned on this point.
• Accounting version N (global institution including foreign branches) is a different coding dimension from Preliminary version N; for B 2.4, the handbook lists Preliminary (N) and does not list a Final (D) submission.

Sources and References

• CSSF, Instructions relating to table B 2.4, Participating interests and subordinated loans (update November 2025): https://www.cssf.lu/wp-content/uploads/Instructions_aux_Banques_B_2.4.pdf
• CSSF, Table B 2.4 reporting template (English version, November 2025, illustrative): https://www.cssf.lu/wp-content/uploads/B24_verEN_final.xlsx
• CSSF, Reporting requirements for credit institutions: https://www.cssf.lu/wp-content/uploads/Reporting_requirements_final.pdf
• Circular CSSF 18/686 (update of table B 2.4): https://www.cssf.lu/wp-content/uploads/cssf18_686eng.pdf
• Circular CSSF 14/593 as amended (financial information reporting): https://www.cssf.lu/wp-content/uploads/cssf14_593eng.pdf
• CSSF, Prudential reporting for credit institutions (hub, including B 2.4 eDesk submission arrangements): https://www.cssf.lu/en/prudential-reporting-credit-institutions/
• Regulation (EU) No 575/2013 (CRR): https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32013R0575
• Commission Delegated Regulation (EU) No 241/2014 (own funds RTS): https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32014R0241

Before the Next Annual B 2.4 Filing

The first filing under the November 2025 format, for the 31 December 2025 reference date, was due on 11 March 2026. The next standard annual filing is for the 31 December 2026 reference date, with a deadline of 11 February 2027. Confirm that every directly held participation and subordinated loan reconciles to its F 01.01 portfolio, that the new residence, classification and consolidation columns pull from the CRR view of each counterparty rather than the accounting ledger alone, and that any indirect holding is captured in the separate letter to the CSSF. Then set the recurring reminder for the 31 December reference date and the 11 February deadline that governs every year after this one.

Disclaimer: The information on RegReportingDesk.com is for educational and informational purposes only. It does not constitute legal, regulatory, tax, or compliance advice. Always consult your compliance officer, legal counsel, or the relevant supervisory authority for guidance specific to your institution.