PDF formats
When sending a document for signature via Addo Sign, it must be in PDF format. We support transactions in PDF version 1.7 and newer, corresponding to PDF/A-3 or later.
You cannot send documents in PDF/A-1 or PDF/A-2 formats (equivalent to PDF versions 1.0–1.6), as these do not support the changes needed to apply digital signature stamps.
If your document meets the correct PDF/A format (a legal requirement in several Nordic countries), it will be returned to you in signed form, in the same PDF/A version as originally uploaded.
PDF/A Version Overview
There are multiple formats of PDF/A. Here, we will provide an overview of how to determine which versions fall under the different PDF/A formats:
• PDF/A-1 = PDF version 1.0 - 1.4
• PDF/A-2 = PDF version 1.5 - 1.6
• PDF/A-3 = PDF version 1.7 - 1.9
• PDF/A-4 = PDF version 2.0 -
How to Check the PDF Version
To check the PDF version of your document:
1. Open the PDF document in Adobe Acrobat Reader
2. Press File
3. Then click Properties
4. The PDF Version field will show which version it is
How to Convert to a Newer PDF/A Version?
To convert your document to a newer version, follow these steps:
1. Press File
2. Press Print
3. Press and select "printer"
4. Select Microsoft print to PDF
5. Press Print
6. Then, choose a name and location for the PDF document that you have just converted to a newer PDF version.
Addo Print - From Word to signing
It is not possible to send documents other than a PDF for signature? No, but you can send documents for signature directly from Word with Addo Print.
PDF/A Compatibility Errors
If you receive an error message stating that your PDF document cannot be distributed or uploaded for signing, it may be due to a general issue with PDF/A compliance. This means the document does not meet the technical standards required for secure digital signing in Addo Sign.
Common causes include:
The document is in an outdated PDF/A format (such as PDF/A-1 or PDF/A-2)
The file contains elements that are not allowed in PDF/A (e.g., multimedia, encryption, or non-embedded fonts)
How to Ensure PDF/A Compliance
If you're using Adobe Acrobat, follow these steps to prepare a compatible document:
1. Save as PDF/A
Open the PDF in Adobe Acrobat Pro
Go to File → Save As Other → PDF/A
Choose a standard like PDF/A-3b
Save the document
2. Verify PDF/A Compliance
Go to Tools → Print Production → Preflight
Select the profile “Verify compliance with PDF/A”
Run the analysis to check for formatting issues
By following these steps, you can ensure your document meets the required standards and can be signed and distributed without errors.