BR-01: The specification identifier is missing
This code shows up when an electronic invoice is validated. Here is what it means, why it fires, and what to change in the file.
Why this code appears
The invoice does not declare which specification it follows (BT-24). It is the very first field a recipient reads: without it, they do not know which rules to apply, and they reject the document before opening it.
How to fix it
Write the profile identifier into GuidelineSpecifiedDocumentContextParameter/ID, for example urn:cen.eu:en16931:2017#compliant#urn:factur-x.eu:1p0:basic for the BASIC profile. It must match EXACTLY the profile the invoice actually complies with.
Where it happens
This code comes from EN 16931, the European e-invoicing standard. It concerns business term BT-24.