…in its version 304.13.25 does not work out of the box in Dynamics 365 for Finance, unfortunately. First and foremost, the public entity’s order number (the Customer requisition at the sales header order or in the project contract funding source details) is a must! As you specify the Customer requisition, a reference to the PO line number reference becomes mandatory, too. Yet this invoice line-level field is either malformed or missing. Moreover, Austria always requires an email address of the supplier (us) which is disabled or not working in all 4 standard ER formats. This can be the default e-mail address of the company in the legal entity settings.

As a good start, I recommend the excellent blog series E-Invoice in D365FO for Norway – Part 1 (Intro) – DynFOTech

The core configuration includes specifying the Endpoint ID of the supplier (ours) under Bank account / Routing number in the legal entity parameters, and providing the conversion of the units of measure into the UN standard, see the blog above.  For every unit of measure there must be an own Code ‘axis’ to compensate for the well known design flaw in the external code values cardinality in Dynamics 365 for SCM:

Then, to finally make it work, you have to extend all 4 standard electronic formats from Microsoft and make at least the following changes:

Format changes