E-invoice and digital reporting requirements for cross-border B2B transactions

Starting 1 July 2030, suppliers and service providers engaged in cross-border business to business (B2B) transactions will be required to issue electronic invoices within ten days of service delivery or goods supplied. These invoices must comply with the updated EN16931 standard, expected in September 2025, and Directive 2014/55. Summary invoices are permissible for monthly supplies, with issuance deadlines set ten days post-month-end. However, Member States (MSs) have the option to prohibit certain sectors, especially those prone to fraud, from using summary invoices.

When an e-invoice is issued for intra-EU goods or services, the supplier or an authorized third party must simultaneously report a subset of data to the tax authorities, a process known as real-time digital reporting.

For self-billed transactions, data submission is required within five days post-invoice issuance. Recipients must report transaction data within five days unless alternative controls are in place by the Member States. Business will be happy to hear that the digital reporting system, starting on 1 July , 2030, will not duplicate but replace the obligation to submit an EC Sales List (ESL) for intra-EU transactions.

E-invoice and digital reporting requirements for domestic transactions

Beginning in April 2025, Member States may implement mandatory e-invoicing for domestic B2B and business-to-customer (B2C) transactions without needing authorization from the EU Commission. Additionally, the issuance of an e-invoice does not require the recipient's permission if they are established within the same Member State.

Member States with existing domestic e-invoicing or/and digital reporting systems must ensure they align with the framework for intra-EU transactions by January 2035. This requirement applies to Member States that, as of January 1, 2024, either have a system in place, have received authorization from the EU Commission, or have enacted relevant national legislation without requiring authorization. Countries that fall under these conditions are notably Italy, France, Poland, Germany, Romania, and Belgium. Countries like Spain, Croatia, and Greece, which sought authorization after this date, are not included.

E-invoicing in Luxembourg

To date, the most well-known standardized framework for electronic document exchange in Luxembourg is likely Peppol (Pan-European Public Procurement Online), as it is the platform used for business-to-government (B2G) transactions. Originally developed by a Belgian association, Peppol has become widely adopted across Europe and beyond. Although initially designed for public procurement—as it is used in Luxembourg—it is now also being widely used for business-to-business (B2B) e-invoicing, as seen in Belgium, and around the world, beyond EU borders.

Luxembourg’s position regarding the implementation of mandatory e-invoice and digital reporting for domestic transactions is not yet clear.

E-invoicing in the neighboring states

While Luxembourg has the opportunity to wait and watch, neighboring countries have already announced their agendas for implementing domestic B2B/B2C e-invoicing mandates:

• Belgium will need to comply with mandatory e-invoicing for domestic B2B transactions as of 1 January, 2026, requiring all VAT-registered businesses to issue and receive electronic invoices in a structured format.
• Germany is introducing B2B e-invoicing in phases, with the mandatory receipt of e-invoices beginning in January 2025 and becoming fully mandatory for all businesses by January 2028.
• France will implement mandatory B2B e-invoicing for all VAT-liable businesses in phases: Large and mid-sized companies must comply by September 2026, while smaller businesses will be required to do so by September 2027.

Despite the fact that Luxembourg might not impose domestic B2B/B2C e-invoicing before 1 July 2030, the progress detailed above will significantly impact Luxembourg businesses that have suppliers or clients in these neighbouring countries, pushing them to adopt e-invoicing to facilitate seamless, efficient transactions across borders. This shift, driven by business needs rather than legal mandates, might encourage Luxembourg-based companies to enhance their digital capabilities and competitiveness in the evolving European market.

The first step is developing a clear understanding of the business, technical and legal requirements involved. This includes creating business requirements definition that captures functional needs and regulation compliance conditions.

A detailed gap analysis allows organization to proactively identify deficiencies in their current systems and processes that may hinder e-invoicing regulation compliance. This analysis highlights where current ERP capabilities fall short such as the inability to generate structured XML invoice data or integrate securely with tax portals via APIs and helping define the necessary enhancements to meet technical and regulatory requirements effectively.

The solution design stage focuses on building an efficient e-invoicing architecture within the ERP system. This includes designing API integrations for seamless communication with national Invoice Registration Portals (IRPs) or using third-party middleware platforms. The data flow is defined from invoice creation through transformation into regulatory schema, submission to IRP and reception of approval responses. It also encompasses exception handling, error logging and mechanisms to manage rejected invoices.

Following the design phase, the ERP system is configured to activate the e-invoicing capabilities. Technical developments may include building connectors for payload generation, authentication protocols, QR code generation and response management. Security configurations for handling digital signatures or certificates are also implemented to ensure data integrity and compliance with country-specific mandates.

Rigorous testing ensures the end-to-end process functions as expected. Unit tests cover individual components like invoice generation and XML formatting, while integration testing verifies full data flow from ERP to IRP and back. User acceptance test allows key users from finance, procurement and IT to validate system functionality against scenarios, ensuring it meets business requirements and identify errors or bottlenecks early and ensures regulation compliance with regulatory formats.

For successful adoption, end-users across finance, procurement and IT must be trained on the new processes. Change management activities help employees understand the benefits of the new system, increasing adoption and ability to handle errors during day-to-day operations. Proper training ensures higher efficiency, accuracy and user confidence.

A phased rollout starting with a pilot group enables organizations to validate performance and gather feedback. Once the system goes live, continuous monitoring of invoice submissions, status updates and audit logs is crucial. Tracking Invoice Reference Numbers (IRNs), QR codes, and validation responses supports regulatory compliance and process transparency. 

Invoices originate in the ERP or accounting system during typical business events such as sales cycle or service deliveries. At this stage, all essential fields such as buyer/seller details, item codes, taxes and totals are completed.

The system retrieves the generated invoice data and triggers the submission process using an interface connector. This typically leverages the Application Interface Framework (AIF), ensuring smooth data handover to the transformation engine.

Invoice data is mapped to a standardized, country-specific XML format. The AIF applies validation checks to ensure the schema and content adhere to local regulations. The XML file is then queued for transmission.

An integration platform, either in-house or cloud-based, handles communication with government portals. This service submits the validated XML data, authenticates the request and logs each step to maintain traceability.

Responses from tax authorities approval, rejection or correction advice are captured, interpreted and translated into a format the ERP can process. The invoice status is updated accordingly, ensuring users have real-time visibility.

Finally, the system archives both the invoice and its response metadata. This includes IRNs, QR codes, and error logs. Archiving ensures adherence to legal retention requirements and provides an audit-ready history of all transactions. 

The integration between ERP systems and tax platforms requires precise data mapping, secure communication and real-time validation. Varying formats and APIs across jurisdictions increase the complexity. Moreover, poor data quality or outdated master data can cause rejection at the tax portal. 

Initial setup costs for compliance infrastructure, licensing and development can be substantial. However, these costs are often outweighed by long-term savings and risk mitigation. Legally, ensuring proper archiving, audit trails and cross-border compliance (where applicable) is essential. 

Adopting e-invoicing touches multiple departments. Finance, supply chain and customer service teams must adapt their processes and respond to real-time invoice validations. Monitoring system performance and adapting to evolving mandates add further complexity, requiring continuous operational oversight.