When you sign PDF document using a signature, y ou basically confirm its contents “as is”. Consequently, any other changes made afterwards, invalidates the signature and thus, you would know if the document was altered.

In contrast, certifying a document first allows you to specify the changes that a user can make to the document without invalidating the certification. In other words, the document would still be considered to retain its integrity and the recipient could still trust the document.

For example, say you send around a PDF file containing formal paper work which needed to be signed by a number of people. How could each recipient determine if the document wasn’t altered by any of the previous signers? A certified document could be set up to allow only those signatures to be appended to the PDF document and nothing else.

In order to certify a PDF, save the PDF as a Certified document. You can certify a document by using your digital ID to sign and confirm the certification. Then you would sign the document to verify your document before sending, as usual. Certifying a PDF allows more flexibility for the sharing of your documents.