How to Fix PDF Signature Not Allowed After Emailing
Question details
The user is unable to digitally sign a PDF received via email because the software indicates that signing is not allowed, despite the sender's original settings.
- Product
- Device & OS
- not provided
- Scenario
- Opening a PDF file received as an email attachment in order to add a digital signature.
- Observed behavior
- The PDF software displays a "Signature: Not Allowed" status and restricts the user from applying a new digital signature.
Ensure you download the PDF directly to your local drive and open it with a dedicated PDF editor, as viewing the document within an email client preview often restricts digital signing features.
Verify Document Security Settings and Permissions
Check the specific security properties in your PDF reader to determine if a certification signature or permission setting is blocking new signatures.
Even if the original sender intended to allow signatures, applying a certification signature or certain document restrictions before emailing can lock the file for subsequent recipients.
Open the downloaded PDF file and navigate to File > Properties.
Click on the Security tab to review the Document Restrictions Summary.
Look for the 'Signing' entry to see if it is listed as 'Not Allowed'.
Open the Signature panel on the left side of the screen to check if a previous certification signature is restricting further modifications.
Request the Original Unsigned PDF
If the PDF was locked by a previous signer or corrupted during email transit, getting a fresh copy is the fastest workaround.
Easily Sign and Secure PDFs with WPS Office
WPS Office provides a powerful built-in PDF editor that allows you to easily add digital signatures, manage permissions, and edit documents without encountering unexpected locking issues.
- 1. Open the PDF: Launch WPS Office and open your PDF document from your local drive.
- 2. Navigate to the signature tool: Click on the 'Protect' or 'Fill & Sign' tab located on the top ribbon.
- 3. Create your signature: Click the 'Sign' button to create a new digital signature or insert an existing one.
- 4. Apply and save: Place the signature in the designated field on the page and save the document to apply the changes securely.
Frequently Asked Questions
Why does a PDF become locked after the first person signs it?
When applying a digital signature, the signer has the option to certify the document or lock it to prevent further modifications. If they check the 'Lock document after signing' option, no subsequent recipients can add a signature.
Does emailing a PDF change its internal security settings?
Generally, emailing a PDF does not alter its internal security settings. However, opening the file directly within a web browser or a basic email attachment viewer can temporarily disable advanced features like digital signatures. Always download the file and open it in a dedicated PDF application.
How can a sender allow multiple signatures on a single PDF?
The creator of the PDF must set up multiple digital signature fields beforehand and ensure that document certification settings are configured to allow form fill-in and subsequent digital signatures before sending the file out.
