The work to standardise e-business is carried out within the framework of the Sector Standardisation Committee for e-Business, appointed by the OIO Data Standardisation Committee.
So far, the work has resulted in OIOXML electronic invoicing and OIOUBL. OIOXML was introduced as mandatory on 1 February 2005 for all public authorities in Denmark. The rules about OIOXML electronic invoicing were incorporated in an Executive Order. On April 12th 2010 this Executive Order was superseded by Executive Order no. 354 of 26 March 2010 (see below).
Since may 2011, it has been mandatory for suppliers to the Danish Public sector to send invoices electronically in UBL 2.0 format more specifically the Danish customization of UBL, named OIOUBL. The rules are stated in Executive Order on Information in and Transport of, OIOUBL Electronic Invoices for Electronic Settlement with Public Authorities - No. 354 of 26 March 2010, issued by the Danish Ministry of Science, Technology and Innovation.
Prior to passing the executive order, the Ministry evaluated UBL 2.0 as being the only present XML-based e-invoicing standard to comply with the business requirements of the Danish Public Sector. Download the official statement on the evaluation of UBL and the future plans for the Danish public sector use of e-invoice standards.