OIOUBL is Denmark's national format for e-invoices and other procurement documents, based on UBL and maintained by the Danish Business Authority (Erhvervsstyrelsen). Danish public bodies receive invoices in it through the Nemhandel network. The current version, OIOUBL 2.1, dates from May 2022. In March 2026 the Authority cancelled OIOUBL 3 and set out a move to Peppol BIS, expected to be complete by mid-2029.
What is in the OIOUBL package?
| Property | Value |
|---|---|
| Maintained by | Danish Business Authority (Erhvervsstyrelsen) |
| Syntax | UBL, with Danish rules and code lists |
| Current version | 2.1, May 2022, an update of 2.02 from September 2009 |
| Legal documents | invoice, credit note, reminder, application response |
| Other documents | catalogue, order, order response, statement |
| Public-sector profiles | Procurement-BilSim and NES Profile 5 Basic Billing |
The executive order on OIOUBL electronic invoices took effect on 12 April 2010 and covers the four invoicing documents (OIOUBL 2.1 documentation, in Danish). The documentation also publishes validation files, a display stylesheet and code lists.
From OIOUBL to Peppol BIS
The Danish Business Authority's strategy of March 2026 phases out the OIOUBL e-invoice in favour of Nemhandel BIS 4, built on Peppol BIS 4 with Danish extensions. OIOUBL 2.1 stays in force until that transition is ready, and the move is expected to be complete by mid-2029 (Erhvervsstyrelsen, in Danish). Bookkeeping system providers must support both OIOUBL and Peppol BIS in the meantime. See Peppol BIS Billing and Peppol PINT.
What does Klarbon do with OIOUBL?
Klarbon does not open, check or write OIOUBL files today; support is planned. It works with Peppol BIS Billing 3.0, which Danish systems also exchange. This is general information, not tax advice.
Related
Frequently asked questions
What is OIOUBL?
The Danish national e-invoice and e-procurement format based directly on the UBL 2.0 and 2.1 schemas, maintained by the Danish Business Authority (Erhvervsstyrelsen). Danish public bodies receive OIOUBL invoices through the Nemhandel network.
Which OIOUBL version is current?
OIOUBL 2.1, an update in May 2022 of OIOUBL 2.02 from 2009. The Danish Business Authority keeps 2.1 in force until the move to Peppol BIS.
What happened to OIOUBL 3.0?
The Danish Business Authority cancelled the OIOUBL 3 invoice package. Its March 2026 strategy plans a move from OIOUBL to Peppol BIS 4 with Danish extensions, expected to be complete by mid-2029.
What is the difference between OIOUBL and Peppol BIS?
Both are UBL invoices. OIOUBL is a Danish format with its own rules and richer data for automation, such as payment through NemKonto. Peppol BIS Billing is the European Peppol specification based on EN 16931.