CSSF B 2.5 B and B 2.5 E Reporting: Luxembourg Staff Costs and Taxes

Once a year, credit institutions within scope report the CSSF’s B 2.5 national return. The survey uses sub-template B 2.5 B for staff expenses and sub-template B 2.5 E for taxes, with B 2.5 E populated only in accounting version L. The CSSF calls the pair its Survey on staff expenses and taxes. The tables are annual and reflect the last day of the institution’s closing month; they must be transmitted by 11 February irrespective of the closing month. The survey sits outside the quarterly rhythm that COREP and FINREP teams follow, which can make the annual deadline easier to deprioritise without an external trigger.

The two tables carry a specific filing trap: B 2.5 E is reported only in accounting version L, so the accounting version must match the CSSF-prescribed L/S/N scope. A reporting officer who maps each element once, covering legal basis, scope, data points, calendar, XBRL mechanics, and validation rules, can prepare and file the survey clean.

Related reading: FINREP Reporting Explained

The legal basis for B 2.5 B and B 2.5 E: Circular CSSF 17/664

The survey sits in the Luxembourg accounting reporting scheme (schéma de reporting comptable), a set of national tables the CSSF built on top of the CEBS FINREP framework as revised on 24 July 2007. The core balance-sheet and profit-and-loss tables in that scheme mirror the European FINREP; a smaller group, including B 2.5, was adapted for the specifics of the Luxembourg banking sector, with elements added or removed. Table B 2.5 E on taxes was a later addition, introduced in July 2009 with taxonomy version 1.04.

Circular CSSF 17/664 introduced the annual survey in 2017 but is now marked outdated by the CSSF. The continuing B 2.5 B and B 2.5 E obligation is reflected in Circular CSSF 14/593 as amended, the CSSF prudential-reporting page and the Reporting requirements for credit institutions handbook, while the B 2.5 technical requirements are set out in the national Schedule of Conditions linked by the CSSF. Circular CSSF 14/593, the umbrella circular on supervisory reporting requirements applicable to credit institutions, confirms that the national tables not covered by the common European reporting remain applicable, and lists staff expenses (table B 2.5 B) and details on taxes (table B 2.5 E) as updated by Circular CSSF 17/664. The tables are drawn up on an IAS/IFRS basis, consistent with the rest of the accounting reporting scheme.

One status point matters for anyone building a source-of-truth reference. On its public document register, the CSSF marked Circular 17/664 as archived and outdated as of 20 May 2026. That flag does not, on its own, tell you the obligation was withdrawn: the CSSF manual Reporting requirements for credit institutions, in its November 2025 version, still lists B 2.5 B and B 2.5 E with an annual frequency and the 11 February remittance. Because Circular 17/664 is now marked outdated, the current governing source and operational instructions should be confirmed from the live CSSF regulatory framework, prudential-reporting page and Reporting Handbook rather than inferred from the archived circular.

Who must report the staff-cost and tax survey

The obligation falls on credit institutions, not on the wider population of supervised entities. Investment firms and other professionals of the financial sector are outside this particular scheme; the survey belongs to the bank accounting reporting scheme. Within the credit-institution population, the CSSF technical documentation frames the duty as applying to all credit institutions subject to the sending obligation, and the version you file depends on your branch structure.

Three cases decide the answer. A Luxembourg-law credit institution with foreign branches files B 2.5 B in three accounting versions: version L for the Luxembourg head office alone, version S for each foreign branch, and version N for the global institution including its branches. A Luxembourg-law credit institution without foreign branches files version L only. Luxembourg branches of foreign credit institutions were brought into the accounting reporting scheme in version L for the B 2.1 and B 2.5 tables, so the same version-L logic applies to them; a filer in that position should confirm the current treatment in the CSSF manual, which sets out the branch sections separately.

The tax table narrows the scope further. B 2.5 E is reported only in accounting version L. Luxembourg-law institutions do not submit it in version N or S; Luxembourg branches of EU and non-EU credit institutions established in Luxembourg also submit B 2.5 E in version L.

What the report contains: staff expenses in B 2.5 B, taxes in B 2.5 E

B 2.5 B captures staff expenses as a breakdown that foots to a total. The CSSF calculation rules define a total line (line 6.100) as the sum of the component lines beneath it, including an other-expenses line, so the table is a small vertical structure of staff-cost components rather than a single number. B 2.5 E captures tax details across several numbered columns, with a total column (column 5) defined as the sum of the preceding columns for the relevant lines, plus internal consistency rules that bound one line against another within a column. The exact line and column labels are set out in the CSSF template, while the taxonomy package contains mapping tables between B 2.5 and the XBRL taxonomy elements; a filer should map fields against the published CSSF template and mapping files rather than against memory.

Drawing the boundary clearly: the common European FINREP already collects administrative expenses, staff costs and tax expense within its own templates under the EBA implementing technical standards. B 2.5 B and B 2.5 E sit alongside it as a separate national data collection with their own layout, taxonomy and calendar.

Two mechanical conventions travel with the data. All amounts are reported in the currency of the institution’s capital, defined as an ISO 4217 unit, and a single file may carry only one currency. The CSSF rounds every numeric value it receives, including percentages, to a maximum of two decimal places internally, so precision beyond that point is not preserved on the supervisor’s side.

Deadlines: the annual 11 February remittance

The calendar is the shortest part of the survey. The operative dates are fixed:

• Reference date: the institution’s accounting year-end, i.e. the last day of its closing month.
• Frequency: annual.
• Remittance: 11 February of the following year (the CSSF annual remittance slot shown as H2 in the reporting-requirements manual).
• First application: reference date 31 December 2017.
• Non-December financial year-end: follow Chapter 3, Section 2 of the CSSF reporting-requirements manual, which sets the specific reference-date instruction.

Here is where a filer coming from the older documentation gets caught. The 2011 technical document describes B 2.5 as a quarterly table due on the fifteenth of the month after quarter-end. That describes the pre-2017 arrangement. Circular CSSF 17/664 recast the staff-expenses and tax tables as an annual national survey from the 31 December 2017 reference date, and the current manual reflects that annual cadence. Reading the old quarterly cadence into today’s obligation is a calendar error to avoid; the survey is annual, and the year now closing is due by the 11 February remittance that follows it.

Submission: XBRL format, the FINREP taxonomy and the SOFiE/E-File channels

The survey is filed electronically only. Paper submission is expressly excluded. Each table is defined by a CSSF reference taxonomy: B 2.5 uses the taxonomy identified as t-FINREP-lu-B25, the internal CSSF table code is B25, and the layout is L0. For each reporting period and applicable accounting version, table B 2.5 is transmitted as a package containing exactly one XBRL instance. B 2.5 B and B 2.5 E are sub-templates of B 2.5; only the applicable B/E information is populated, while B 2.5 A, C and D are left empty. The reporting context uses the institution’s CSSF signalétique number and the prescribed instant/duration period structure.

File naming follows the scheme’s convention. Under the B 2.5 Schedule of Conditions, a package delivered with the same name as an earlier package is treated as a correction and cancellation of the previous package.

The CSSF prudential-reporting page confirms B 2.5 is transmitted via SOFiE or E-File; the Reporting Handbook’s external-channels section carries it under the ‘FRCREP’ file-naming convention. Table B 2.4 moved to eDesk/API from 1 February 2026.

Validation rules and the common rejection causes

Because B 2.5 B and B 2.5 E are national tables, they are policed by the CSSF’s own rules rather than by the EBA validation rule set that governs the common European reporting. The calculation rules in the technical document are the first gate: within B 2.5 B the total staff-cost line must equal the sum of its components, and within B 2.5 E the total column must foot across the contributing columns for each line, with the internal bounding rules between lines respected. These arithmetic relationships are the CSSF calculation rules for B 2.5 and should be checked before submission. Running the arithmetic before XBRL construction, rather than relying on the CSSF feedback cycle to surface errors, keeps the 11 February deadline from becoming a resubmission exercise. In practice, preparing a pre-submission reconciliation that ties the B 2.5 B total staff-cost line and the B 2.5 E column totals against underlying source accounting data gives the reporting officer a documented audit trail as well as a quality gate before the XBRL instance is transmitted.

Look at the return the way a data-quality reviewer would, and three failure modes stand out. First, populating cells the CSSF does not expect: the institution reports only the numbered columns that are not shaded grey in the published template, and information supplied beyond what the reporting permits risks a rejected file. Second, mixing currencies: defining more than one currency across the file or files is prohibited, even though it is technically possible. Third, the version error on the tax table: B 2.5 E is confined to version L and must not be reported in version N or version S.

For B 2.5, apply the national Schedule of Conditions for XBRL construction and validation. That document contains the B 2.5 calculation rules and states that only numbered, non-grey cells in the published Excel tables are to be reported; information beyond the permitted reporting may lead to rejection.

Caveats and interactions with the common European FINREP

The survey belongs to a small family of Luxembourg national returns that the CSSF kept in place when the common European reporting took over most accounting data. The same CSSF national-reporting page also lists B 2.4 on participating interests and subordinated loans, B 4.5 on shareholdings and B 4.6 on persons responsible for certain functions and activities. B 4.6 was updated by Circular CSSF 18/695 after Circular CSSF 13/576, and both circulars are now marked outdated. A team that owns one of these usually owns the others, and they share the same national logic even though their frequencies and versions differ.

The interaction that causes the most confusion is with FINREP itself. The common European FINREP is set by the EBA implementing technical standards, Commission Implementing Regulation (EU) 2021/451, subsequently replaced by Commission Implementing Regulation (EU) 2024/3117, and it is remitted quarterly, semi-annually or annually depending on the template. B 2.5 B and B 2.5 E draw their heritage from the same FINREP family but are national tables under a Luxembourg circular. Treating the annual staff-cost and tax survey as a by-product of the FINREP submission, or assuming an EBA validation pass covers it, is the interaction error to avoid. Practitioners who need the wider European picture can start from the FINREP reporting guide and the sibling COREP reporting explained, then treat the B 2.5 survey as its own deliverable.

Proportionality is another point where filers over-read. The full, simplified-extended and over-simplified FINREP versions apply to the common European financial reporting, and the survey should not be assumed to inherit those tiers; the version that matters for B 2.5 B and B 2.5 E is the accounting version, L, S or N, driven by branch structure, with B 2.5 E fixed at version L. Where a filer is unsure how a non-standard year-end or a group structure affects the reference date, the manual’s specific-instructions chapter is the reference, not an analogy with FINREP.

Recent and upcoming changes to B 2.5 reporting

The substantive change already happened in 2017, when Circular CSSF 17/664 moved staff expenses and tax details onto an annual footing with a first reference date of 31 December 2017.

Two current points belong on the watch list. First, B 2.5 remains an XBRL submission through SOFiE or E-File/external channels, while B 2.4 moved to eDesk/API from 1 February 2026. Second, Circular CSSF 17/664 has been marked outdated since 20 May 2026, while the live CSSF prudential-reporting page continues to list B 2.5 B and B 2.5 E as an annual national return. Any future change to the B 2.5 channel or governing source should be confirmed from the live CSSF material.

For the broader Luxembourg reporting calendar and how the survey slots alongside the quarterly returns, the CSSF reporting calendar and the mechanics of the CSSF eDesk reporting portal give the operational context that the survey itself omits.

Frequently Asked Questions

Our bank has no foreign branches. Which versions of B 2.5 B and B 2.5 E do we file?

A Luxembourg-law credit institution without foreign branches files version L only for both tables. Version S exists for foreign branches and version N for the global institution, so neither applies when there are no branches to consolidate.

Do Luxembourg branches of foreign banks have to file the tax table B 2.5 E?

B 2.5 E is confined to version L, the Luxembourg establishment. Luxembourg branches of EU and non-EU credit institutions established in Luxembourg submit B 2.5 E in version L. Confirm the current branch treatment in the CSSF reporting-requirements manual, which sets out the branch sections separately from the head-office sections.

Our financial year does not end on 31 December. What is our reference date?

The reference date is the accounting year-end. For most Luxembourg credit institutions that is 31 December, but institutions with a different closing month use that month-end instead. The manual’s Chapter 3, Section 2 carries the specific reference-date instruction for non-December year-ends.

Do the EBA validation rules apply to this survey?

No. B 2.5 B and B 2.5 E are national CSSF tables. Their XBRL-instance requirements are specified in the national Schedule of Conditions, which contains the B 2.5 calculation rules; the handbook’s EU/EBA XBRL-validation section is separate.

How do we correct a B 2.5 filing after submission?

Under the B 2.5 Schedule of Conditions, a package delivered under the same name is treated as a correction and cancellation of the earlier package. Follow the B 2.5 naming convention when submitting the corrected instance.

We had no amount for one staff-cost component. Should we report a zero?

For B 2.5, follow the national Schedule of Conditions and published template for the required facts. The handbook’s ‘unnecessary zero values’ rule sits in the section for reporting areas governed by Regulation (EU) No 575/2013, not in the B 2.5 national-reporting section.

In which currency do we report the survey?

In the currency of the institution’s capital, defined as an ISO 4217 unit, with a single currency per file. Mixing currencies in one file is prohibited.

Related Articles

• FINREP Reporting Explained: How the common European financial reporting framework works and where its staff-cost and tax data sit.
• COREP Reporting Explained: The prudential own-funds and risk return that shares the Luxembourg reporting calendar with the survey.
• CSSF Reporting Calendar: How Luxembourg reference dates and remittance deadlines fit together across returns.
• CSSF Prudential Reporting via eDesk: The CSSF eDesk portal and the submission mechanics for Luxembourg supervised entities.
• IFRS 18 and FINREP Interim Templates: The accounting-standard changes flowing into the financial reporting the survey draws from.

Key Takeaways

• File the CSSF Survey on staff expenses and taxes, tables B 2.5 B and B 2.5 E, annually for the institution’s accounting year-end, with remittance by 11 February of the following year irrespective of the closing month.
• B 2.5 E, the tax detail, is version L only. Do not populate it in version N or version S.
• B 2.5 B runs in versions L, S and N for banks with foreign branches, and version L only for banks without branches.
• The survey is a national CSSF return distinct from the common European FINREP; an EBA validation pass does not cover it.
• Report in a single currency, the capital currency, as an ISO 4217 unit; the survey is XBRL only, with no paper channel.
• A B 2.5 package submitted under the same name is treated as a correction and cancellation of the prior package.
• For a non-December financial year-end, take the reference date from Chapter 3, Section 2 of the CSSF reporting-requirements manual.
• Re-confirm the governing instrument: Circular CSSF 17/664 was marked archived on the CSSF register on 20 May 2026 while the obligation remained in the November 2025 manual and the live CSSF prudential-reporting page.

Sources and References

• Circular CSSF 17/664, Survey on staff expenses and taxes, 31 July 2017: https://www.cssf.lu/en/Document/circular-cssf-17-664/
• CSSF, Document technique relatif a la transmission des tableaux du schéma de reporting comptable (SOC FINREP, version 1.04): https://www.cssf.lu/wp-content/uploads/SOC_FINREP_final_clean_150211.pdf
• CSSF, Templates B 2.5 B and B 2.5 E: https://www.cssf.lu/wp-content/uploads/Templates-B-2.5-B-and-B-2.5-E.xlsx
• CSSF, FINREP taxonomy package version 1.04: https://www.cssf.lu/wp-content/uploads/CSSF_FINREP_1.04.zip
• CSSF, Reporting requirements for credit institutions: https://www.cssf.lu/wp-content/uploads/Reporting_requirements_final.pdf
• Circular CSSF 14/593 (as amended), Supervisory reporting requirements applicable to credit institutions: https://www.cssf.lu/wp-content/uploads/cssf14_593eng.pdf
• CSSF, User Guide for XBRL reports, Bank prudential reporting (eDesk and S3): https://www.cssf.lu/wp-content/uploads/Bank_prudential_reporting.pdf
• Commission Implementing Regulation (EU) 2021/451 (EBA ITS on supervisory reporting): https://eur-lex.europa.eu/eli/reg_impl/2021/451/oj
• Commission Implementing Regulation (EU) 2024/3117 (EBA ITS on supervisory reporting): https://eur-lex.europa.eu/eli/reg_impl/2024/3117/oj
• CSSF, Prudential reporting for credit institutions (yearly B 2.5 B and B 2.5 E, 11 February deadline, SOFiE or E-File): https://www.cssf.lu/en/prudential-reporting-credit-institutions/
• CSSF, National Reporting B2.4, new eDesk procedure (8 January 2026): https://www.cssf.lu/en/2026/01/national-reporting-b2-4-new-edesk-procedure/

Getting the B 2.5 survey out the door by 11 February

Map staff expenses to the B 2.5 B lines and tax details to the B 2.5 E columns against the CSSF template, set B 2.5 E to version L, confirm the single reporting currency, and build the XBRL instance against the t-FINREP-lu-B25 taxonomy. Before the 11 February remittance, confirm the SOFiE or E-File transmission route for B 2.5 and re-confirm the governing instrument on the CSSF register, given that Circular 17/664 now shows as archived. With those two checks done, the XBRL instance is ready to transmit before the 11 February remittance.

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.