Executive Summary
Luxembourg’s tax landscape saw significant legislative progress this week. Parliament held the first constitutional vote on Bill 8775, transposing the June 2026 tripartite agreement covering personal and corporate tax reforms. Separately, lawmakers adopted a historic single tax class for individuals effective 2028, replacing the current three-class system. The government also confirmed mandatory B2B e-invoicing from January 2028 under the EU ViDA package. On the administrative side, the ACD issued circulars clarifying venture capital, patent box, and notional interest deduction regimes, released technical specifications for Country-by-Country Reporting, and PwC updated guidance on public CbCR obligations for non-EU multinationals.
Important Updates
Parliament Advances Tripartite Agreement Tax Measures via Bill 8775
On 28 October 2026, Luxembourg’s Chamber of Deputies conducted the first constitutional vote on Bill No 8775, which transposes the tripartite agreement concluded on 8 June 2026 between the government, trade unions, and employer federations. This agreement is a cornerstone of Luxembourg’s social dialogue and typically triggers sweeping reforms to personal income tax brackets, social security contributions, tax credits for low-income earners, and measures to support purchasing power. The Administration des Contributions Directes (ACD) highlighted this milestone in its 30 October newsletter, signalling that the legislative process is advancing toward final adoption.
While the full text of Bill 8775 is not yet public, tripartite agreements historically adjust the income tax tariff (Article 104 L.I.R.), modify the employee tax credit (CIS), revise the solidarity surtax, and amend deductions for professional expenses. The 2026 agreement likely includes an increase in the minimum social wage, indexing of tax brackets to inflation, and targeted relief for households facing rising energy costs. Corporate provisions such as net wealth tax for companies or stock option plan taxation may also be amended to align with competitiveness goals. The measures will affect all resident and non-resident taxpayers earning Luxembourg-source income, including cross-border workers from France, Belgium, and Germany, as well as multinational enterprises with Luxembourg subsidiaries.
The first constitutional vote does not enact the law; a second vote is required after a minimum three-month interval unless the Council of State waives it. If the second vote occurs in early 2027, most provisions would apply retroactively to 1 January 2027 or upon publication in the Mémorial. Taxpayers should prepare for revised 2027 withholding tax scales and updated annual tax return forms (Model 100/163). The ACD will issue implementing circulars once the law is final. Non-compliance with new withholding rates could trigger penalties under Article 176 L.I.R. Stakeholders are advised to track the legislative calendar on the Chamber’s website and subscribe to ACD newsletters.
Sources: Administration des Contributions Directes Newsletter
Single Tax Class Adopted for Individuals Effective 2028
On 28 October 2026, the Luxembourg Parliament formally adopted Draft Law No. 8676, introducing a single tax class for individual taxpayers effective 1 January 2028. The legislation replaces the existing three tax classes (Class 1 for single individuals, Class 1a for single parents and seniors, Class 2 for married couples and civil partners) with a unified tax class applicable to all resident individuals regardless of marital or family status. The new single class will apply a uniform progressive rate schedule, eliminating the splitting advantage currently enjoyed by married couples under Class 2. To mitigate potential tax increases for certain households, the draft law incorporates adjusted tax brackets and enhanced tax credits for dependent children and single parents, aligning the tax treatment of married couples with that of cohabiting partners.
The change directly affects over 300,000 resident households. Dual-income married couples who currently benefit from income splitting may face higher effective tax rates unless offset by the revised brackets, while single parents and low-income earners stand to gain from expanded refundable tax credits. Cross-border commuters (frontier workers) from France, Belgium, and Germany, who constitute nearly 50% of the workforce, will also be subject to the new class under existing bilateral tax treaty provisions. Employers and payroll providers must update withholding tax systems (RTS) by 1 January 2028 to reflect the unified class.
The law enters into force on 1 January 2028, with a transitional provision allowing taxpayers to opt for the old regime for the 2027 tax year. The ACD will issue implementing circulars by mid-2027 detailing revised withholding tables, tax credit calculations, and reporting obligations for employers. Non-compliance with updated RTS filing may attract penalties under Article 176 LIR. Taxpayers are advised to simulate 2028 liabilities using the new brackets once published in the Mémorial A.
Sources: PwC Luxembourg Newsletter
Mandatory B2B E-Invoicing Set for January 2028
PwC Luxembourg published a comprehensive guidance document on 23 October 2026 detailing the upcoming mandatory business-to-business (B2B) electronic invoicing regime scheduled to take effect from 1 January 2028. The mandate stems from the Law of 25 March 2026 transposing the EU VAT in the Digital Age (ViDA) package and the national e-invoicing framework aligned with the European standard EN 16931. The regulation requires all VAT-registered entities established in Luxembourg to issue, receive, and store structured electronic invoices for domestic B2B transactions via the Peppol network or an equivalent certified service provider. Paper and PDF invoices will no longer satisfy VAT invoicing requirements for B2B supplies, though B2C operations and certain financial services are excluded.
Approximately 45,000 Luxembourg VAT-registered businesses, including SMEs, large corporations, and foreign branches with a permanent establishment, must comply. Multinational groups with shared service centers in Luxembourg will need to integrate e-invoicing into ERP systems (SAP, Oracle, Microsoft Dynamics) and ensure interoperability with Peppol access points. The financial services sector, representing 25% of GDP, faces specific challenges due to high invoice volumes and VAT exemption complexity. Non-resident traders making taxable supplies in Luxembourg must also adhere if they hold a Luxembourg VAT registration.
The hard deadline is 1 January 2028 for issuance and reception capabilities. A voluntary pilot phase runs from 1 January 2027, allowing early adopters to test connectivity with the Peppol network. Entities must archive e-invoices for 10 years in accordance with Article 63 of the VAT Law, ensuring authenticity of origin, integrity of content, and legibility. Penalties for non-compliance include fines up to €2,500 per invoice under Article 69 VAT Law and potential VAT deduction denial. PwC recommends initiating ERP upgrades by Q2 2027 and conducting end-to-end testing with trading partners by Q4 2027.
Sources: PwC Luxembourg Guidance Document
Secondary Regulatory & Regional Updates
- ACD Issues Circulars on Venture Capital, Patent Box, and Notional Interest Deduction: On 30 October 2026, the ACD published three circulars clarifying L.I.R. Articles 152ter (venture capital investment certificates), 154quater (IP income/patent box), and 154quinquies (notional interest deduction). The circulars define qualifying venture capital vehicles and 50% capital gains exemption conditions, detail the OECD-modified nexus ratio calculation for the 80% IP income exemption, and update the reference interest rate for fiscal year 2027 with hybrid mismatch guidance under ATAD II. Effective for 2026 fiscal year assessments (filed in 2027); taxpayers should review structures and update Model 500 returns. Administration des Contributions Directes Newsletter
- Electronic Filing Manual and XSD Schema Released for Country-by-Country Reporting: The ACD published the user manual and XSD schema (v2.0) on 14 October 2026 for electronic Country-by-Country Reporting (CDC) implementing EU Directive 2016/881 and OECD BEPS Action 13. MNE groups with consolidated revenue ≥€750 million must file FY2025 data by 31 December 2026 via the eCDF portal using LuxTrust or eIDAS certificates. Paper filing is no longer accepted. A pre-validation environment is available for testing; dry-run recommended by 30 November 2026. Penalties up to €25,000 per violation apply for late or erroneous filings. Administration des Contributions Directes Newsletter
- Public CbCR Filing Readiness Update for Non-EU Multinational Groups: PwC Luxembourg updated guidance on 16 October 2026 for non-EU ultimate parent entities (UPEs) subject to the Public CbCR Directive (EU 2021/2101) as transposed by the Law of 20 December 2023. Luxembourg subsidiaries or branches designated as surrogate parent entities must file a public CbCR in XBRL via eCDF within 12 months of fiscal year-end. For FY2024, the deadline is 31 December 2025. Non-EU groups without EU-level publication must file a limited report covering only Luxembourg operations. Late filing incurs €1,250/month penalties (capped at €25,000). Groups should finalize surrogate parent designations and perform data gap analysis on non-financial metrics. PwC Luxembourg Briefing
Disclaimer: This article is compiled and summarized by the AI based on publicly available information and is for general information purposes only. It does not constitute any form of formal tax advice, legal opinion, or basis for performance. Please consult a qualified professional tax advisor or legal counsel for tax advice.