UBL warnings lead to invalid status

[Dataporti]

Dear KoSIT Team,

In a recent case, we rejected a BIS Billing 3.0 invoice based on the validation result from KoSIT Validator 1.5.
The validation of the schematron rules for EN16931 (UBL) led to six warnings (UBL-CR-411, UBL-CR-453, UBL-CR-459, UBL-CR-561, UBL-CR-678, UBL-CR-679), but still resulted in the status invalid. We did not customize the configuration of the validator in this regard.
We are now in discussion with the sender of the message, who is pointing out that warnings alone should not lead to the rejection of the invoice.
Based on some research into this behavior of the KoSIT validator, I now assume that the reason for the rejection is that these warnings often lead to major business issues, and that KoSIT therefore decided to implement a rejection when they occur.
Since I could not find any documentation or explanation to confirm my assumption, I would like to ask you:
1. Is my assumption correct?
2. Is there any documentation regarding this?
3. If 1. is true: Could you please explain why KoSIT decided to implement a rejection based on these warnings?

Thank you!

Kind Regards
Julian
Dataport Team e-invoicing

[phax]

What version of the validation-configuration-bis have you been using?

[Dataporti]

We used the validator configuration of version 1.5 which validates for BIS Billing Version 3.0.19 in this case.

[phax]

I think you need to share the file and/or the output here for further analysis - hard to say without the details

[Dataporti]

Here is the anonymized invoice:

eInvoice_001.xml

[Dataporti]

And here are my outputs of the local validation, which is the same we used for automatically processing the invoice:

eInvoice_001-report.html
eInvoice_001-report.xml

[phax]

Maybe @bdewein can help in explaining that?

[bdewein]

The rep:report/@valid value is false due to the warnings (in this case, non-conformance with EN 16931 requirements). The report recommendation, however, is reject only in case of errors, not warnings. Accordingly, the reports provided above list the Warnings, but recommend to accept the invoice.

[Dataporti]

Thank you for the explanation! So would you recommend changing our decision on the rejection of the invoice to the recommendation of the report and disregard the value in rep:report/@valid?