How to Add a Second Signature to a Digitally Signed PDF
Question details
The user wants to know how multiple people can sign a PDF document after it has already been digitally signed by the first person.
- Product
- Device & OS
- not provided
- Scenario
- Routing a PDF document to collect digital signatures from multiple different individuals.
- Observed behavior
- The PDF document becomes locked after the first person applies their digital signature, preventing subsequent signers from adding their signatures.
Before attempting to collect signatures, ensure you are working with the original, unsigned version of the PDF, as applying a digital signature to a flat document usually locks it for security purposes.
Prepare the PDF with Predefined Signature Fields
Adding designated signature fields before routing the document ensures that it remains open for subsequent signers without breaking the cryptographic seal.
When a standard PDF is digitally signed, the software secures the document to prevent tampering. If no further signature fields are detected, the document locks completely. Predefining the fields tells the software that more signatures are expected.
Open the original, completely unsigned PDF document in your PDF editor.
Locate the 'Prepare Form' or 'Form' tools and insert a blank Digital Signature field for each person who needs to sign the document.
Save the prepared PDF and send it to the first signer. Once they sign in their designated box, the remaining fields will stay active for the others.
Use an E-Signature Workflow Service
For complex documents requiring multiple signatures in a specific order, using a dedicated e-signature workflow tool is the most reliable method.
Easily Manage and Sign PDFs with WPS Office
WPS Office offers a robust set of PDF tools that make it easy to insert signature fields, securely sign documents, and manage multiple signers without the need for expensive software subscriptions.
- 1. Open your PDF: Launch WPS Office and open your unsigned PDF document.
- 2. Access Signature Tools: Navigate to the 'Fill & Sign' or 'Protect' tab located on the top ribbon.
- 3. Add Signatures: Click 'Sign' to place your signature or set up the document fields for multiple signers, then securely save and share the file.
Frequently Asked Questions
Why does a PDF lock after the first digital signature?
A digital signature uses encryption to secure the document and prevent unauthorized tampering. If the document was not pre-configured with additional signature fields, the software locks the entire file to ensure the contents and the first signature remain valid and unchanged.
What is the difference between a scanned signature and a digital signature?
A scanned signature is simply an image (like a JPG or PNG) placed onto a page and offers no actual security or proof of identity. A digital signature uses a certificate-based digital ID to cryptographically verify the signer's identity and secure the document from further edits.
Can I unlock a PDF after it has been digitally signed to add another signature?
No, a digitally signed PDF generally cannot be unlocked without invalidating the existing signature. If additional signatures are required but no fields were prepared, you must start over with the original, unsigned version of the document.
