Denmark e-Invoicing Guide

Denmark was one of the first countries to mandate electronic invoices for government suppliers, doing so as early as 2005. The country's NemHandel infrastructure and OIOUBL format have been central to Danish digital governance for nearly two decades.

While B2B e-invoicing remains voluntary, Denmark has introduced digital bookkeeping requirements under the Danish Bookkeeping Act that effectively push businesses toward digital invoice management. In March 2026, Erhvervsstyrelsen published a strategy to transition from OIOUBL to Nemhandel BIS 4, a national format based on Peppol BIS 4 with Danish extensions using the PINT architecture. The transition is expected to be fully completed by mid-2029, after which OIOUBL will no longer be supported.

Denmark's e-invoicing timeline reflects its long history with electronic invoicing. B2G has been mandatory since 2005, with the current requirement (via OIOUBL on NemHandel) effective since April 2019. The planned OIOUBL 3.0 update was cancelled in January 2026, and in March 2026 Erhvervsstyrelsen published a strategy to replace OIOUBL with Nemhandel BIS 4 (based on Peppol BIS 4 with PINT architecture). The migration path includes a release candidate (November 2027 to May 2028), final release (May 2028), Nemhandel BIS 4 becoming mandatory (November 2028), and OIOUBL 2.1 phase-out (by May 2029). Digital bookkeeping requirements for businesses above DKK 300,000 turnover took effect in January 2026, and registered bookkeeping systems must support SAF-T 2.0 by January 2027.

All government suppliers must submit invoices electronically via NemHandel using the OIOUBL format. B2B e-invoicing is voluntary. Businesses can choose to adopt Peppol or OIOUBL for their trading partners, but there is no legal obligation to do so. Under the published Nemhandel BIS 4 strategy, OIOUBL will be replaced by Nemhandel BIS 4 by May 2029. The initial scope covers invoices, credit notes, and invoice responses; other document types such as e-orders and e-receipts will remain in both OIOUBL and Peppol formats for the time being.

Under the Danish Bookkeeping Act, businesses with annual turnover above DKK 300,000 must use approved digital bookkeeping systems that must support SAF-T 2.0 from January 2027. While this does not mandate e-invoicing specifically, it drives adoption of digital invoice handling. B2C transactions are entirely outside any e-invoicing framework, and small businesses below the turnover threshold are exempt from digital bookkeeping requirements.

Denmark uses a decentralised exchange model. Businesses connect to NemHandel or the Peppol network through access points, using CVR numbers for routing. There is no central government clearance or pre-authorisation. Invoices are exchanged directly between parties through the network.

For B2G, invoices must currently be in OIOUBL format and submitted via NemHandel. Under the Nemhandel BIS 4 strategy, Denmark will transition to a single format based on Peppol BIS 4 with the PINT (Peppol INTernational) architecture. PINT allows Danish national extensions to be layered on top of the international Peppol core without breaking cross-border interoperability. Once complete, the Bookkeeping Act requirement for digital systems to support OIOUBL will be removed, requiring only Nemhandel BIS support.

Penalties in Denmark primarily apply to B2G obligations and compliance with the Bookkeeping Act. Government suppliers risk payment delays or invoice rejection for non-electronic submissions, while businesses that fail to comply with digital bookkeeping requirements face fines and potential business registration restrictions.