---
title: "Qualified Digital Signature"
slug: "1672771958"
updated: 2026-07-01T09:33:32Z
published: 2026-07-01T09:33:32Z
canonical: "help.ila.cegid.com/1672771958"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.ila.cegid.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Qualified Digital Signature

According to Portuguese [Ordinance no. 8/2022-XXIII](https://info.portaldasfinancas.gov.pt/pt/informacao_fiscal/legislacao/Despachos_SEAF/Documents/Despacho_SEAF_8_2022_XXIII.pdf), all tax relevant documents issued **must** include the **qualified digital signature** as of **01/01/2024**. This legal requirement is applicable to all companies that:

- choose to send their invoices via email in PDF format;
- issue electronic invoices in XML format and in other EDI templates;
- invoice to Public Administration entities.

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## Legal Framework

The qualified digital signature is a requirement of electronic invoicing that aims to ensure **authenticity** and **veracity** in the printing of your documents. This mechanism unequivocally identifies the **entity responsible** for issuing the document(s), as well as ensures data **integrity**.

An invoice becomes electronic from the moment it incorporates a qualified digital signature. For that, documents in electronic format must be **signed in a qualified manner** using an **electronic seal** or **qualified digital signature**.

During the year 2023, the invoices you issue on Invoicing Engine and send by email in PDF format will be in accordance with the legislation. However, and although it is not yet mandatory, the Invoicing Engine will provide **integration with AMA and YET** to include the qualified digital signature in your PDF documents. To find out more information, just fill out the following [form](https://campaigns.primaverabss.com/acton/media/17591/assinatura-digital-qualificada?sid=TV2:FHICvOis7#contacto).

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## Frequently Asked Questions

The following frequently asked questions aim to clarify any doubts you might have on this requirement:

**1. Is the electronic signature the same as digital signature?**

In practice, there is no difference between the two. The official term used by the Portuguese Government is "**qualified electronic signature**". However, in order to distinguish this signature from electronic invoicing, the term "**qualified digital signature**" has been more commonly used.

**2. What is the difference between the Qualified Signature and the Qualified Seal?**

The qualified digital signature contains **information on the person signing** the document, and the electronic seal only contains **encrypted information identifying the company**. However, the two mechanisms serve the same purpose, that is, to authenticate.

**3. Is the qualified digital signature mandatory?**

Yes. As of **01/01/2023**, all tax relevant documents sent by **email** must contain the qualified digital signature.

**4. Which documents must contain the qualified digital signature?**

All tax relevant documents, such as: invoices, budgets, transportation documents, credit and debit notes.

**5. If I have the qualified digital signature, can I send the invoice via email?**

Yes. The invoices, by being sent electronically, **need** to obtain a **qualified digital** **certificate**. This certificate includes a signature and encrypted key and will ensure the automatic and legal recognition of the digital signature for your company in Portugal and in the entire European Union.

**6. Is my company included?**

The qualified digital signature is **mandatory for all companies** that wish to **send their invoices as a PDF****via email.**