When submitting documents to official entities or public services across the EU, you may be required to use a Qualified Electronic Signature (QES) that complies with eIDAS regulations. These signatures are legally equivalent to handwritten ones but must meet strict technical standards, including being based on a qualified certificate.
Even if you’ve signed your document with a QES, some systems may still reject it — often due to the format of the signed PDF file, not the signature itself.
Common Error Messages
While messages vary depending on the institution or platform, a typical example is:
“Your signature is invalid: Your summary has been modified, but is not electronically signed with the correct certification level.”
This often means the system could not detect the QES certificate properly, which may be due to submitting the wrong file type, such as a PDF portfolio.
What Is a PDF Portfolio?
A PDF portfolio is a container file that can include multiple embedded files (such as attachments, signed documents, or metadata). Some signature providers deliver signed documents in this format.
Unfortunately, many EU validation systems do not support portfolio files, and will reject them even if the QES inside is valid.
What to Do
If you’re facing signature validation errors:
- Open the downloaded file in Adobe Acrobat
- Check if the file is a PDF portfolio (you’ll see attached documents inside)
- Locate and extract the actual signed PDF — usually labeled with the document name
- Submit the extracted PDF file (not the portfolio) to the requesting authority or platform
Verify Your Signature Online
You can check if your document contains a valid Qualified Electronic Signature using the official EU signature validator: 👉 EU DSS Signature Validation Tool