Digitally Sign Existing PDF Add a digital signature to an existing PDF document. A document that already carries digital signatures receives the new signature as an incremental update that keeps the existing signatures valid. PdfEditor keeps the standard (PDF/A, PDF/UA etc.) of the source PDF Enter PDF File URL Upload PDF File Clear File Open Password User Password: Owner Password: Digital Signature Information Reason: Location: Contact: PAdES Profile and Timestamp Profile: Auto (B-T with a timestamp server, B-B otherwise) PAdES B-B (basic signature) PAdES B-T (signature timestamp) Certification: Approval signature (not certified) Certify: no changes allowed Certify: form filling and signing allowed Certify: form filling, signing and annotations allowed Timestamp server: Signature field: The sample agreement is already signed by the client and the signature goes into its empty ManagerSignature field, so the result carries two signatures and the first one stays valid. When the document has no field with the given name, or the name is left blank, a new signature field is added at the bottom of the first page. The sample form Form_With_Signature_Fields.pdf has both signature fields empty. Digital Signature Appearance Settings Enable Appearance Signature Text: Sign PDF