How to digitally sign the invoice PDF

What is it for?

An invoice emailed to the customer as a PDF is an electronic invoice. A digitally signed PDF assures the customer that the file is authentic. The Sign PDF button saves a signed copy of the PDF on the invoice, next to the original, which does not change.

The screen quotes the law: “DL 28/2019, art. 12.º”. Pending validation by a certified accountant: when the qualified signature is mandatory and when another way of guaranteeing authenticity is enough.

When to use it?

• Before emailing the PDF of an issued invoice or credit note.
• When the invoice shows the warning “The PDF of this invoice has no qualified signature”.
• Do not use it to correct an invoice: the signed PDF is a copy, the certified document does not change.

Where to find it?

• Signature provider: Settings › Billing, PT Certification section, Electronic invoice signature field.
• Button: on the issued invoice, in Billing › Invoice › Customer invoices.

Before you start

• To choose the provider, your profile is Administrator (the field only appears to this profile). Each company has its own.
• To sign, your profile is Billing: the button was used with it in this article.
• The invoice is issued (Posted) and belongs to a Portuguese company. You do not need to attach the PDF: fiscaldoo signs the invoice's own PDF.

How to use it

1. With the Administrator profile, open Settings › Billing and, in the PT Certification section, open the Electronic invoice signature field. Choose Simulated (tests) or Multicert (qualified signature) and click Save.
2. Open the issued invoice. While it has no accepted signed PDF, the invoice shows the warning “The PDF of this invoice has no qualified signature: sent by email, its authenticity is not guaranteed (DL 28/2019, art. 12.º). Use “Sign PDF” before sending it.” and the Sign PDF button.
3. Click Sign PDF. The screen refreshes without showing any message: the warning and the button disappear.
4. Check the invoice's attachments: there is a file with the PDF name and “(signed)” (in the example, FT_D26_30.pdf (assinado)).

Expected result

• The invoice has the “… (signed)” attachment, with the signature accepted.
• The number, the ATCUD and the signature of the certified document do not change.
• The accepted signed PDF cannot be changed or deleted: it is evidence of what was sent to the customer.

Important notes

In the demo only the simulated provider works

Simulated (tests) signs as a test: no real signature is made. Multicert (qualified signature) is the option for the real signature, but on a test database it is blocked (see “Common problems”). Pending validation on screen: the Multicert message on a production database, which can only be seen outside a test database; the code of the current version indicates that the connection to this provider has not been delivered yet. Check with your fiscaldoo provider before relying on the qualified signature.

• A PDF is not signed twice.

Common problems

“No signature provider is chosen”

• Symptom: when you click Sign PDF: “No signature provider is chosen for Empresa Demonstração, Lda, so the PDF cannot be signed. (…) Ask the system administrator to choose the provider in Settings › Billing › PT Certification.”
• What to do: ask the Administrator to do step 1.

“The real signature provider (Multicert) is blocked in a test database”

• Symptom: with Multicert chosen, on a test database: “The real signature provider (Multicert) is blocked in a test database: nothing real leaves a test environment. Choose the simulated provider to try the flow.”
• What to do: on a test database, choose Simulated (tests).