RE: Message rejected (MLR)
What it means
Peppol RE in a Message Level Response means the received document was rejected, usually because it failed validation. A description of the reason must be given.
The usual cause
Check the rejection description and line responses for syntax errors (SV) or fatal rule errors (BV); BW warnings alone must not cause rejection.
How to fix it
Fix every error the response describes, check the file again and send the corrected invoice.
Once the file is corrected, check it again for free: Validate a Peppol BIS invoice
Or fix the invoice in a form and download the corrected file, for 1 credit: Fix a rejected e-invoice
The code as published
Read the official document . Source: Peppol BIS Message Level Response 3.0 (BIS 36A), with its code lists, version Peppol BIS 3, 2026-Q2 release, published by OpenPeppol AISBL, read on 8 November 2026.
Klarbon explains each code in its own words; the official wording is in the document linked above.
Look at your file
Check the invoice against the rules this portal applies: Validate a Peppol BIS invoice. Validate a Peppol BIS invoice