The invoices and tax-relevant documents sent electronically must contain the digital signature from 1 January 2023.

So, according to  Decree-Law no. 28/2019, of 15th FebruaryAs of 2023, invoices will only be valid if they incorporate a qualified digital signature.

What is a Qualified Digital Signature?

The qualified digital signature or qualified electronic signature or digital signature is an exclusive, non-transferable recognisance that identifies the company responsible for issuing the digital document, guaranteeing the integrity of the data it contains and can only be issued by an accredited entity.

This digital signature must be generated from a device called a QSCD (Qualified Signature Creation Devices). This device gives documents legal validity equivalent to handwritten signatures in all EU member states.

It is important to note that only organisations accredited by the National Security Office and mentioned in the Trusted List published by the European Commission are able to generate a digital signature with legal value and electronic seals must be generated by a device for creating digital signatures and seals. 

What are the differences between the Qualified Digital Signature and the Qualified Seal?

A qualified digital signature contains information about who is signing the document, while an electronic seal contains only the encrypted information that will identify the company. Although both mechanisms are different, they fulfil the same objective of authenticating documents.

Which documents must include a digital signature?

All invoices and tax-relevant documents must bear a qualified digital signature.

Which companies are covered by this obligation?

This obligation is aimed at all companies that choose to send PDF invoices by email as an alternative to paper invoices. Find out more about electronic invoicing.