If an invoice keeps returning with the status "Rejected by server," the reason for the error is indicated in the document itself — you just need to find it and read it, rather than guessing in advance.
How to view the rejection reason
Log in to the IS ESF system and open the "Invoice Log." Find the document with the status "Rejected by server" there — this is the one causing the problem. Open this document: the error text is usually displayed at the top of the document. After reading it, you will understand exactly what the server does not accept in this ESF, and you will be able to make corrections before resubmitting.
Frequently Asked Questions
Where exactly should I look for the document status?
In the invoice log of the IS ESF, each document displays its processing status. Look for the value "Rejected by server" — this is the problematic document.
Is the error not fitting or hard to see?
Open the document in full — the error text is shown at the top, usually as a separate message or a note attached to the document.
What should I do after finding the cause?
Fix the issue indicated in the message in the document and resubmit the ESF.