Email Invoice for Denmark

Electronic invoicing in Denmark is a well-established practice, with a clear distinction between Business-to-Government (B2G) and Business-to-Business (B2B) transactions. For B2G transactions, e-invoicing has been mandatory since 2005, requiring all suppliers to public authorities to submit their invoices electronically. Public authorities are obligated to accept and process these e-invoices, provided they comply with the European Standard EN 16931, typically exchanged via the national NemHandel platform.

While B2B e-invoicing is not yet universally mandatory for issuance, the 2022 Bookkeeping Act significantly impacts all businesses by requiring them to possess the capability to send and receive structured electronic invoices. This Act mandates the use of digital bookkeeping systems (DBS) that support structured e-invoicing and the generation of Standard Audit Files for Tax (SAF-T).

Compliance deadlines for the Bookkeeping Act are phased:

• July 1, 2024: Applied to companies required to submit annual reports and already using registered bookkeeping systems.
• January 1, 2025: Extended to companies submitting annual reports but using non-registered or custom-built accounting systems.
• January 1, 2026: The requirement will apply to businesses without an annual reporting obligation, such as sole proprietorships, if their annual net turnover has exceeded DKK 300,000 for two consecutive years. For those using in-house accounting systems, the deadline is expected to be July 2026.

Non-compliance with B2G e-invoicing regulations can lead to severe consequences, including automatic rejection of invoices, payment delays, audits, administrative fines, and even potential exclusion from future government contracts.

Denmark's e-invoicing framework is built upon specific technical standards to ensure interoperability and compliance, heavily influenced by European directives. The primary required e-invoicing formats for B2G transactions have historically included both Peppol BIS 3.0 and the national OIOUBL 2.1.

A significant development in the Danish e-invoicing landscape is the recent decision to discontinue the planned OIOUBL 3.0 format, which was formally cancelled on January 14, 2026. This move signals Denmark's strategic shift towards a unified document standard, increasingly aligning with the international Peppol ecosystem. The country is now phasing out OIOUBL 2.1 in favor of NemHandel BIS 4, a localized adaptation of the international Peppol BIS 4 format, with a release candidate anticipated in 2028 and migration expected through mid-2029.

The European Standard EN 16931 plays a crucial role, having been adopted by Danish public authorities. This standard defines the core elements and semantic data model for electronic invoices, ensuring they are structured, machine-readable, and compatible across EU systems. All public contracting authorities in Denmark are required to accept and process e-invoices that comply with EN 16931 for public procurement contracts above EU thresholds. Peppol BIS 3.0 is fully aligned with this European standard.

Implementing e-invoicing in Denmark involves several practical steps to ensure compliance with the evolving regulatory framework, particularly the 2022 Bookkeeping Act. The core requirement is for businesses to utilize compliant digital bookkeeping systems (DBS). These systems, whether certified solutions or custom-built ERP systems, must be capable of issuing, receiving, storing, and archiving structured electronic invoices, as well as generating Standard Audit Files for Tax (SAF-T) upon request.

Here are the key steps for implementation:

• Select a Compliant Digital Bookkeeping System: Choose a system that is either certified by the Danish Business Authority (Erhvervsstyrelsen) or a custom solution that demonstrably meets all legal requirements. If using a non-registered system, the business bears full responsibility for compliance.
• Integrate with NemHandel or Peppol: To exchange e-invoices, your system must be connected to the NemHandel platform, Denmark's national infrastructure, or the Peppol network. NemHandel is interconnected with Peppol, offering flexibility.
• Ensure Data Authenticity and Integrity: The chosen e-invoicing system must guarantee the authenticity and integrity of invoice data. This includes implementing robust IT security measures, such as user and access management, and ensuring automatic weekly backups to a secure server, ideally with an independent third party located within the EU/EEA.
• Establish Archiving Procedures: All electronic invoices and related accounting records must be securely stored for a minimum of five years from the end of the financial year to which they relate.
• Prepare for SAF-T Generation: Your digital bookkeeping system must be capable of generating SAF-T files, an electronic format for reporting tax and financial data, upon request from the Danish Tax Agency (Skattestyrelsen).
• Document Bookkeeping Procedures: Businesses are required to create and maintain a formal, written description of their bookkeeping procedures, clearly outlining internal controls and responsibilities.

Structured electronic invoices are fundamental to public procurement in Denmark, serving as a cornerstone of the country's highly digitalized public sector. Since 2005, it has been mandatory for all suppliers to public authorities to submit their invoices electronically. This mandate underscores the critical importance of structured invoices in facilitating efficient and transparent government transactions.

The key benefits of structured invoices in public procurement include:

• Streamlined Processes: Structured invoices contain data in a machine-readable format, enabling automated processing by public entities. This significantly reduces manual data entry, minimizes human error, and accelerates the entire invoice-to-payment cycle.