Electronic signature concept

The advanced electronic signature is an accreditation system that allows the signatory to be identified . Furthermore, the qualified electronic signature , which is the advanced electronic signature that is created using a qualified electronic signature creation device and is based on a certificate, has the same value as the handwritten signature ; therefore, it authenticates the communications generated by the signatory.

Thus, the advanced electronic signature constitutes legal evidence that gives it probative value, so its legal effect cannot be denied because it is presented in electronic format or because it does not meet the requirements of a qualified electronic signature.

An electronic invoice will have the same legal validity as an invoice issued on paper, if the electronic document, in addition to meeting certain requirements in terms of content, guarantees the authenticity of its origin and the integrity of its content, with the qualified electronic signature being the accreditation mechanism.

It is Regulation (EU) No. 910/2014 of the European Parliament and of the Council of 23 July 2014 on electronic identification and trust services for electronic transactions in the internal market and repealing Directive 1999/93/EC (eIDAS Regulation 910/2014/EC , hereinafter) which in its article 3.12 defines the qualified electronic signature as the advanced electronic signature that is created using a qualified electronic signature creation device and that is based on a qualified electronic signature certificate.

Article 26 of the same eiDAS Regulation 910/2014/EC mentions the requirements for advanced electronic signatures: a) be uniquely linked to the signatory; b) allow the identification of the signatory; c) have been created using electronic signature creation data that the signatory can use, with a high level of confidence, under their exclusive control, and d) be linked to the data signed by the signature in such a way that any subsequent modification of the data is detectable.

Likewise, article 3.15 of the eiDAS Regulation 910/2014/EC establishes that "qualified electronic signature certificates" are electronic signature certificates that have been issued by a qualified trust service provider and that meet certain requirements that the Regulation lists in its Annex I, such as the indication that the certificate has been issued as a qualified electronic signature certificate, the identification of the qualified trust service provider, the name of the signatory or pseudonym, etc.

Signature formats

Although the eiDAS Regulation 910/2014/EC and its complement, Law 6/2020, of November 11, regulating certain aspects of electronic trust services, legally establish the framework of the qualified electronic signature, from a technical point of view.

Facturae defines two electronic signature formats:

  • Basic Advanced Electronic Signature Format: contains the minimum and necessary elements for the signature to be considered an advanced electronic signature. This profile corresponds to the XADES-EPES signature of the XADES ETSI TS 101 903 standard.
  • Advanced electronic signature format with validation information: incorporates, in the basic format, additional information to the signature necessary for its validation. For example, time stamp as evidence that the signature existed before a certain point in time, information about the certification chain and revocation status, information that provides evidence to third parties or potential arbitrations. Likewise, the long-term validation of the signature is ensured, regardless of whether or not the Certification Authority exists.

What certificates can I use to sign the invoice?

The competent Ministry (as of January 2022 it is the Ministry of Economic Affairs and Digital Transformation) publishes on its website the qualified trusted Electronic Service Providers (the link is https://sedeaplicaciones.minetur.gob.es/Prestadores/

Likewise, there are different digital certificate profiles valid for the electronic signature of the invoice:

  • Qualified Electronic Seal Certificate : allows the telematic identification and electronic signature of entities, companies and other legal persons. Allows digital signing without incorporating representative or proxy data. It is especially suitable for authentication and unassisted signature in automated processes, such as the generation of invoices.
  • Qualified certificates for natural person legal representative: allows the holder to act on behalf of the entity or organization to which they belong.
  • Individual certificates: applicable for self-employed people and professionals, as is the case with the electronic DNI.