How to Add Multiple Certificate-Based Signatures to a PDF Form
Question details
The user needs a method to allow two different people to fill out and digitally sign the same PDF form using certificate-based signatures without the second signature invalidating the first.
- Product
- Device & OS
- not provided
- Scenario
- A PDF form requires multiple signers where the second signer must update specific form fields after the first person has already signed it.
- Observed behavior
- To achieve the workflow, the document must be configured to permit specific field updates so that subsequent digital signatures do not break the validity of previous ones.
Ensure both signers have valid digital certificates installed on their devices and that the PDF form contains the necessary designated form fields and signature blocks for both users.
Use Incremental Signing and Configure Field Permissions
Set up the first digital signature so it permits the second signer to fill in specific fields and add their own signature without breaking the document's security.
When a document is digitally signed, any unauthorized changes will break the signature's validity. To allow a second person to fill out form fields and sign, the first signer must use incremental signing and explicitly define permitted actions prior to saving.
Ensure the PDF has designated form fields to be filled by the second person, as well as distinct signature blocks for both the first and second signers.
When the first person signs, choose the option to 'Certify' or 'Sign' the document with restrictions. Select the security setting that permits 'Form fill-in and digital signatures' rather than locking the entire document.
Save the document after the first signature is applied. This locks the main content but leaves the specified fields open for the next person.
The second person opens the document, fills in their permitted fields, and applies their own certificate-based signature to their designated signature block.
Sign PDF Forms with Digital Certificates in WPS Office
WPS Office provides a comprehensive PDF toolkit that allows you to easily add, manage, and validate certificate-based digital signatures on your forms, ensuring document security and integrity.
- 1. Open your PDF form: Launch WPS Office and open the PDF document that requires your signature.
- 2. Access the Protect tab: Navigate to the 'Protect' tab on the top ribbon and click on 'Sign Document' or 'Digital Signature'.
- 3. Apply your digital certificate: Choose your personal digital ID or certificate from the list, draw your signature area, and enter your certificate password if prompted.
- 4. Save the signed document: Save the PDF to securely lock your signature onto the document and easily share it with the next signer.
Frequently Asked Questions
Why does the first signature say 'Invalid' after the second person signs?
This happens if the second signer edits content, adds annotations, or modifies fields that were not explicitly permitted by the first signer when the initial signature was configured and applied.
Can I lock the entire PDF after the second person signs?
Yes. When the final person applies their digital signature, they can select an option to lock the document after signing, which prevents any further changes or additions to the PDF.
Do both signers need the same type of digital certificate?
No, each signer uses their own unique digital certificate. However, both certificates must be issued by a trusted Certificate Authority (CA) or be mutually trusted by both parties for the signatures to appear valid on each other's devices.
