2026 marks a pivotal milestone for Denmark’s digital transformation, acting as a strategic crossroads for two major national projects:
- Bookkeeping Act: This year sees the final wave of adoption, mandating that the remaining categories of businesses and foreign entities transition to certified digital bookkeeping systems.
- OIOUBL 3.0 electronic invoice format: Following the postponements of 2025, 2026 is seemingly starting with the outright cancellation of the OIOUBL 3.0 release
Final implementation phase of the Digital Bookkeeping Act
The implementation of the Digital Bookkeeping Act [↗︎] follows a progressive timeline designed to transition the entire Danish economy to digital standards. It requires companies to handle all accounting electronically (including invoicing) via certified solutions [↗︎] or in-house compliant systems.
The first phases, completed between 2024 and 2025, have already brought most Danish domestic companies (so-called Classes B, C, and D) into compliance.
The Act now entered its final stage on January 1st 2026, expanding the obligation to approximately 118,000 small and foreign entities:
- Personally owned businesses and associations with an annual commercial turnover exceeding DKK 300,000 (~40 K€) for two consecutive years.
- Foreign entities that maintain a permanent establishment in Denmark and meet the same DKK 300,000 revenue threshold.
- Subsidiaries of financial and insurance firms, previously exempted, required to submit financial reports
Based on ERST (Danish Business Authority) guidelines, entities opting to develop their own in-house compliant systems are granted a 6-month transition period following the January 1st enforcement, setting the technical compliance deadline to July 1, 2026.
Cancellation of OIOUBL 3.0 implementation
After announcing in 2024 changes to OIOUBL, Denmark’s e-invoicing format, the upcoming 3.0 version of the standard was expected to be the cornerstone of national digital compliance. However, 2025 has been marked by a series of delays and strategic re-evaluations, while the ERST launched a formal review into the standard’s future.
In the end, on January 14, 2026, the digital roadmap took a major turn with the formal cancellation of OIOUBL 3.0 [↗︎]. This reversal leaves organizations in a state of technical uncertainty as they await the new specifications that will replace the discarded OIOUBL 3.0 framework and the new timeline.
Denmark is expected to align more closely with widely adopted European and international standards, likely adopting either the PINT (Peppol INTernational) format or a national CIUS, both compliant with European Norm 16931.
Clarifications are expected on February 24 2026, during the Nemhandelsforum, where the ERST is set to present the finalized strategy and provide further details on the measures intended to broaden e-invoice adoption.
