[UPDATED] New OIOUBL 3.0 invoice standard released in Denmark

[UPDATE 2025/03/31] OIOUBL 3.0 final release, initially planned for April 10, 2025, is postponed to October 2025. The impact on the timeline remains uncertain, but subsequent milestones will likely be delayed by six months.

The domestic standard OIOUBL 3.0 has been published as a “release candidate,” arriving six months later than initially planned. The final release of the standard is scheduled on April 10, 2025. For context, OIOUBL 3.0 is one of the two standards used for all e-invoicing transactions nationwide, along with Peppol BIS 3.0.

Discover the official announcement and access the OIOUBL 3.0 package released by the NemHandel team at the Danish Business Authority (ERST).

Content of the package and main changes introduced

The package includes detailed specifications for invoices, credit notes, and invoice response messages, along with the necessary code lists for these documents.

Then, it introduces a new approach to handling responses, distinguishing between message-level responses (technical confirmations) and business-level responses (content-related acknowledgments). A related requirement mandates that companies issuing invoices must also be capable of receiving the corresponding responses. This obligation extends to institutional end users, ensuring seamless two-way communication across the system.

Furthermore, significant updates have been made to the semantic data model, syntax bindings, field mappings, and calculations to address the limitations of OIOUBL 2.1 and enhance alignment with European Norm (EN) 16931.

Migration timeline

The package also outlines the following implementation plan:

• November 21, 2024 (now): “Release Candidate”. Almost-final specifications for OIOUBL 3.0 are now available, allowing companies to begin development and testing for the new format.
• April 10, 2025: “Final Release”. Final specifications for OIOUBL 3.0 will be available for use in production environments by any voluntary company.
• November 15, 2025: “Phase in”. Support of OIOUBL 3.0 becomes mandatory for all companies using NemHandel.
• May 15, 2026: OIOUBL 2.1 becomes officially deprecated. This signifies the end of support for OIOUBL 2.1, leaving OIOUBL 3.0 as the sole option for all NemHandel transactions.