The electronic signature applies to the entire document, not just to a specific page/s, so it is not necessary to make it visible on all pages. In fact, there is no legal criterion that establishes that a digital signature must be visible on the signed document for it to be valid.

Therefore, we can state that a digitally signed document is perfectly legal, even if it does not have a visible signature on all the pages of the document.

In view of the doubts generated in this regard, the public administration has tended to use CSV (secure verification codes). Basically, the original document without signatures is taken and this code is made visible on all pages of the document, also indicating the address where this code can be validated and checked against the signed document.

This version of the document is qualified as a true copy: it is not the original signed document, but allows access to it.