E-invoicing in Denmark: New requirements starting in March 2027 and the end of OIOUBL
Automatic Registration with NemHandel, SAF-T 2.1, and the Transition to Peppol
Major changes related to e-invoicing are coming in Denmark. On September 22, 2026, the Danish Business Authority (Erhvervsstyrelsen, ERST) issued a regulation Ref. No. 811 , which amends the requirements for digital accounting systems. The start date for the new requirements has been postponed from January 1 to March 1, 2027. At the same time, ERST plans to replace the national OIOUBL e-invoice format with the Peppol-based Nemhandel BIS 4 standard. Companies with Danish subsidiaries or branches must plan for changes to e-invoice workflows in their ERP systems.
Major changes related to e-invoicing are coming in Denmark. On September 22, 2026, the Danish Business Authority (Erhvervsstyrelsen, ERST) issued a regulation Ref. No. 811 , which amends the requirements for digital accounting systems. The start date for the new requirements has been postponed from January 1 to March 1, 2027. At the same time, ERST plans to replace the national OIOUBL e-invoice format with the Peppol-based Nemhandel BIS 4 standard. Companies with Danish subsidiaries or branches must plan for changes to e-invoice workflows in their ERP systems.
When will changes to E-Invoicing take effect in Denmark? Timeline for 2027–2029
- As of January 1, 2027, registered accounting systems must support the SAF-T 2.1 file (Standard Audit File, i.e., a standard XML file containing a company’s accounting data, generated upon request by the tax authority. This is an OECD standard), containing transaction-level data. This deadline has not been postponed.
- On March 1, 2027, system providers must verify customers’ identities and their CVR numbers through MitID and then register the companies with the NemHandel registry.
- January 1, 2028 New requirements are being introduced, including the automatic retrieval of company data from the CVR registry for outgoing documents and a ban on deleting documents from the system.
- In 2028–2029, the OIOUBL format will be replaced by Nemhandel BIS 4, based on Peppol.
What is NemHandel, and how does automatic registration work?
NemHandel is Denmark’s government-run infrastructure for exchanging e-invoices, which includes a recipient registry. After verification by MitID, a company is automatically added to the registry, but it may opt out within 4 weeks or unsubscribe at any time thereafter. The change will affect approximately 350,000 companies using registered accounting systems. National B2B e-invoicing in Denmark remains voluntary, but a valid e-invoice cannot be rejected solely on the basis of its format.
Will OIOUBL Disappear? The transition to Peppol and Nemhandel BIS 4
Nemhandel BIS 4 is the European Peppol BIS 4 standard with a mandatory Danish extension, compliant with the EN 16931 standard. The format change will apply to invoices, credit memos, and responses to invoices. According to the ERST plan:
- November 2027 – May 2028: consultations on the release candidate of the new standard,
- May–November 2028: Nemhandel BIS 4 operates alongside OIOUBL as a voluntary framework,
- November 2028: Nemhandel BIS 4 becomes mandatory, while OIOUBL becomes voluntary,
- May 2029: End of support for OIOUBL 2.1.
E-invoicing in Denmark and SAP: What needs to be adjusted?
Danish companies using SAP should plan to transition the e-invoices they send and receive from the OIOUBL 2.1 format to the NemHandel BIS 4 format. Starting in the spring of 2027, there will be significantly more business partners in NemHandel, so the number of e-invoices entering SAP will also increase. It’s a good idea to get your master data in order now: CVR numbers, P-numbers, and GLN codes.
