More and more, customers are asking to be able to edit signed PDF invoices. We will see here how to put this in place quickly.
A digital invoice, in PDF format, is not a single document. In any case, this is what customers tell me asking me to put electronic signatures in place to make a single document. Obviously, in the eyes of the law, it would be better … As I do not have the mastery of this aspect, do not hesitate to comment on the article to tell me what you think, or better, what you know about the subject!
In the meantime, I must respond to these requests. So I implemented this solution with Adobe Acrobat Pro DC (my client has an Adobe Creative Cloud subscription).
Generate a PDF
Until then it should go. Many products exist to generate PDFs. Acrobat Pro installs a virtual printer. Same for other products such as PDF Creator or DoPDF.
Creating the certificate
The fastest way is to open a PDF document with Adobe Acrobat Pro. Then on the Tools menu, choose Certificates.
The Certificates menu bar appears at the top of the document. Choose to Certify (visible signature). The desired effect is to affix a certificate to the document, and to show a signature on this document.
You will need to draw an area where you want the signature to appear. Note that this will be the same action when you want to sign a document.
Once the area is traced, a window allows you to choose an existing certified signature.
Here I already have an existing certified signature. However, I want to create a second one, to allow another signatory to sign documents. I therefore choose to Configure a new digital ID.
Then you will have to choose the type of digital identity. Obviously, what will be the most secure, and can be imposed, is a certificate provided by a CA (Certification Authority). This type of certificate corresponds to the first two choices (whether in the form of a token or file), but is not free. However, if you have a certificate of this type, use it.
For my part, I choose to Create a digital identification, ie to create a self-signed certificate.
Then I save it to a file. Why in a file and not in a Windows certificate store? Because a certificate created as a file can be protected by a password and that’s what I want. That is, the person who will sign a document, despite the fact that it is with a self-signed certificate, will have to know the password of this certificate. If someone created another certificate with the same information, it will still not be the same certificate, so we attest to the person who signed the document.
You must then fill in the information that will be saved in the certificate, and that will also be displayed on the document, to display a fairly clean signature.
Then you will need to specify where to save the generated certificate, and specify an associated password.
Now you can change the signature that will appear by displaying, instead of the name saved in the certificate, a real scanned signature. Leave the details of the certificate (name, company, date and time of signature) in the right-hand section.
Now, just repeat the procedure to get the desired signature, enter the associated password, and your document will be signed!