The electronic signature internally bounds the document with an electronic certificate, but depending on the signing method can be represented in multiple forms in the body of the document, even without any visible graphic mark (invisible signature).

To validate the authenticity and integrity of a document signed electronically you can use different methods like the following:

• Adobe Acrobat
• ValidE (Gobierno de España)
• SignaSuite (Administració Oberta de Catalunya)

F.A.Q.'s

• I can't see any signature on the document. How can I check if it's electronically signed?

Using any of the methods previously described.

• The document has an electronic signature with a strange format. Is it valid?

The graphic representation of an electronic signature can vary, or even be invisible, depending on the signing software used. If the signature is associed with a valid certificate (you can check it with one of the previous methods) it will be valid, no matter what it look like.

• Is an invisible signature valid in legal terms?

Yes, if the document has a valid electronic signature.

• When validating the document it has no valid electronic signatures, but I can see some in the document.

If you can't find any valid electronic signature after checking several times, it means the document is not an original document but a copy, and can't be validated. If you find a Secure Verification Code (CSV) in the document use it to retrieve the original electronic document from the Electronic Office of its creator and validate it. If it is an UPF document, check it online in the Electronic Office's Document Verification page.