Why a Signed PDF Becomes Locked After One Signature and How to Fix It
Question details
The user wants to know why a PDF document completely locks after applying only the first of multiple required signatures, preventing others from signing.
- Product
- Device & OS
- not provided
- Scenario
- Multiple users need to sign a PDF form, but the document restricts editing and further signing immediately after the first signature is added.
- Observed behavior
- The PDF becomes locked for editing after one signature field is signed, making it impossible to add subsequent signatures or modify the remaining form fields.
Before troubleshooting, ensure you have access to the original, unsigned version of the PDF document. Once a digital signature securely locks a file, the restriction usually cannot be reversed.
Modify Signature Field Properties on the Unsigned Form
Check and adjust the signature field properties to ensure it does not automatically lock the entire document upon signing.
The most common reason a PDF locks after the first signature is that the signature field itself is configured to lock the document once filled. Modifying this setting on the original form prevents the issue for future signers.
Launch your PDF editor and open the original, unsigned version of the document.
Navigate to the Form tab or toolset and select the option to edit form fields.
Right-click the specific signature field that is causing the lock and select 'Properties' from the context menu.
Go to the 'Signed' tab in the Properties dialog. Ensure the 'Lock document after signing' option is unchecked, or change the setting to only lock specific fields rather than the entire document.
Instruct Signers Not to Lock the Document
Ensure that individual signers do not manually select the option to lock the document during their signing process.
Manage PDF Signatures Smoothly with WPS Office
Use WPS Office's built-in PDF tools to manage form fields, collect multiple digital signatures securely, and protect your documents without causing unintended locking issues.
- 1. Open your PDF: Launch WPS Office and open your unsigned PDF form.
- 2. Navigate to the Protect tab: Click on the 'Protect' or 'Form' tab on the top ribbon to access signature and form tools.
- 3. Apply your signature: Click 'Sign' to add your signature without restricting further edits if multiple signers are required.
- 4. Save and share: Save the document and share it with the next person who needs to sign.
Frequently Asked Questions
Can I unlock a PDF that was locked by a digital signature?
Typically, no. A digital signature secures the document's state to prevent tampering. If a document is locked after signing, you will need to start over with an original unsigned copy.
How do I know whose signature locked the PDF document?
You can open the Signature Panel (usually located on the left side of your PDF viewer). It displays the details of all digital signatures, indicating which user's signature locked the file.
What is the difference between certifying a PDF and signing it?
Certifying a PDF is usually done by the document author to specify exactly what changes (like form filling or commenting) are allowed. Standard digital signatures are used by recipients to simply verify their approval or acknowledge the document.
Can I add another signature field after the document is locked?
No, once a document is locked by a digital signature, all form editing capabilities—including adding new signature fields—are permanently disabled to preserve document integrity.
