Hello,

I understand how critical it is for your workflow to meet the strict requirements of invoice validation systems, especially with standards like ZUGFeRD and Factur-X.

Your feedback about this missing functionality has been escalated to our product management team for prioritization, as we recognize the urgency and relevance for workflows like yours. Upvoting on the feature request in the feedback portal will help increase its visibility and priority for future releases.

If you have any additional details about your workflow or specific requirements—such as other metadata you need to set or scenarios where this limitation causes issues—please let me know. This information will help us better understand your needs and advocate for a solution.

Regards,
Dess | Tech Support Engineer, Principal
Progress Telerik

Hello, Vianney,

Thank you for confirming the missing functionality with MIME type handling in Factur-X and PDF/A-3 files. Currently, the PdfProcessing library does not support embedding files with specifying MIME types for attachments. This means that generating fully compliant Factur-X or PDF/A-3 documents with the required MIME type metadata (such as "text/xml" for XML attachments) is not possible with the current version of the library.

I would highly encourage you to cast your vote for the item in order to increase its priority. The more votes an item gathers, the higher its priority becomes. Do not forget to click the Follow button to get notified for any status changes and updates.

Regards,
Dess | Tech Support Engineer, Principal
Progress Telerik