Denmark cancels OIOUBL 3 and moves toward a single e-invoicing standard
On 14 January 2026, the Danish Business Authority announced that the planned release of OIOUBL 3 has been cancelled. The decision follows feedback from service providers, who indicated that supporting another OIOUBL version would require substantial development, testing, and maintenance effort.
This announcement marks a clear turning point after several years of incremental OIOUBL updates. Recent changes already expanded the scope and complexity of the format, including new validation rules and content requirements.
Increasing complexity in the OIOUBL framework
In recent years, Denmark has continued to evolve OIOUBL through targeted updates rather than major version changes. Examples include the introduction of additional data fields and stricter validation logic. One such update was the addition of CO2-related data elements to OIOUBL invoices, reflecting broader sustainability reporting goals.
More background on this development is covered in the article Denmark adds CO2 data to OIOUBL e-invoicing.
In parallel, Denmark also announced stricter OIOUBL validation requirements becoming mandatory in 2026. These validation changes already require companies and service providers to invest in system updates and process adjustments. An overview of these requirements is available in Denmark OIOUBL validation update 2026.
Against this backdrop, the introduction of a full OIOUBL 3 release would have further increased implementation pressure across the market.
From parallel standards to a single national approach
By cancelling OIOUBL 3, Denmark is making a strategic choice to reduce fragmentation in its e-invoicing landscape. Instead of maintaining both Peppol and OIOUBL as parallel standards, the focus will shift toward a single approach going forward.
Maintaining multiple standards has led to overlapping technical requirements, duplicated testing efforts, and higher operational costs for businesses and solution providers. The move toward one standard aims to address these challenges and simplify long-term compliance.
What this means for companies using OIOUBL
OIOUBL remains an important part of Denmark’s current digital invoicing framework, particularly for public sector transactions. The cancellation of OIOUBL 3 does not immediately change existing obligations, including upcoming validation requirements.
However, it does signal that future development will prioritise standardisation, interoperability, and reduced complexity. Companies using OIOUBL should monitor upcoming guidance closely and assess how their current setups align with a longer-term transition toward a single standard.
More guidance expected at Nemhandelsforum
Further details on the revised roadmap are expected to be shared during the Nemhandelsforum on 24 February 2026 in Copenhagen. This event should provide additional clarity on timelines, technical direction, and practical implications for organisations currently working with OIOUBL.
For now, the cancellation of OIOUBL 3 clearly underlines Denmark’s intention to simplify its e-invoicing landscape while building on recent updates rather than expanding the number of standards in use.