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How do I add a certificate signature to a PDF?

March 12, 2024

What Is a Certificate Signature?

While an ordinary signature may suffice for everyday documents, when it comes to signing important documents like business contracts or legal agreements, a PDF certificate signature becomes an indispensable tool to ensure document security and legality.

Advantages of PDF Certificate Signing

  • Document Integrity: Certificate signing ensures that the document has not been tampered with, safeguarding the document's integrity. Once a document is signed, any changes will render the signature invalid.

  • Legal Validity: PDF certificate signatures carry the same legal weight as traditional paper signatures, making signed contracts and legal documents legally valid.

  • Authentication: Digital signatures allow for the verification of the signer's identity, ensuring that the signature belongs to a contract participant or legal professional.

Operation Steps:

Let's demonstrate the steps for creating a certificate signature using a formal purchase contract:

  1. Click "Certificate Sign" > "Add Signature."

  2. Enter the required information in the pop-up window, including your name, encryption Key Algorithm, usage, country, company, and department.

  3. Set a password for the certificate signature (remember this password, as you'll need it for identity verification). The certificate signature can only be inserted into the document after successful authentication.


After setup, you can configure the certificate signing by:

  • Changing the signature style or replacing it with an image or drawing.

  • Adjusting the signature's dimensions.

  • Adding additional elements, timestamps, and reason.

  • Specifying the page range for batch signing multiple pages.


How Can I Ensure the Validity of My Certificate Signing?

  • Once a certificate signature is applied, you cannot move its position or edit the document. Any modification to the document content will invalidate the certificate signature.

  • Double-clicking the signature allows you to view signature details, showing the signed certificate information, signing time, and the signer's identity.


How Do I Manage My Certificate Signings?

Click the "Protect" tab > "Manage Certificate Signings."

  • You can import other certificates stored locally on your computer.

  • You can edit, delete, or export created certificates.


15 years of office industry experience, tech lover and copywriter. Follow me for product reviews, comparisons, and recommendations for new apps and software.