Denmark: OIOUBL 2.1 – Schematron version 1.17.0. 1.17.0. RC

Denmark has released OIOUBL 2.1 Schematron v1.17.0 (Release Candidate), introducing stricter tax code consistency checks, enhanced Peppol VAT code alignment, and mandatory currency validation on amount fields. The final version is expected in mid-February 2026, with mandatory implementation by 15 May 2026, giving businesses additional time to test and adapt their invoicing systems.

The Danish Business Authority has published Schematron version 1.17.0.RC for OIOUBL 2.1 as a release candidate. The schematron is expected to become final in mid-February 2026, provided no major issues are reported. If confirmed, businesses must implement the new version by May 15, 2026.

What’s new in this version?

1. Tax code consistency

-       A new rule ensures that tax codes at line level match the totals at document level,

-       Around 5% of current invoices are expected to be affected.

2. Better Peppol compatibility

-       The VAT code list has been updated to version 1.4,

-       New VAT codes added: B, M, L, K, O, and G (from UNCL5305),

-       This improves conversion between OIOUBL and Peppol BIS invoices.

3. Stricter currency validation

-       All fields ending with “Amount” must now include valid currency codes.

Timeline:

-       Final release: Expected mid-February 2026,

-       Implementation deadline: May 15, 2026

Because these changes may significantly impact existing invoice data, the authority has allowed a longer transition period so businesses and retailers have enough time to test and adapt their systems.