Introduced by the eIDAS Regulation, the electronic seal certifies the origin and content of digital documents. Similar to an electronic signature, it applies to legal entities rather than individuals.

Let’s take a closer look at what the electronic seal is, how it works, and when it should be used—starting from the definitions outlined in the eIDAS Regulation, which governs digital identity and electronic transactions across the EU.

What is the eIDAS Regulation?

The electronic seal was introduced by the eIDAS Regulation (electronic identification and trust services for electronic transactions in the internal market), which provides the legal framework for electronic identification across EU Member States.

Enacted in July 2014 and in effect since 2016, eIDAS establishes the legal ground for electronic signatures, electronic documents, certified email services, and other components related to digital identity in Europe.

Among its key provisions, the Regulation defines electronic signatures and seals and sets out their technical requirements and legal validity, ensuring they are recognized across all EU countries.

What is the Electronic Seal?

The definition of an electronic seal appears in Article 3 of the eIDAS Regulation. It describes a seal as “data in electronic form, which are attached to or logically associated with other electronic data to ensure the latter’s origin and integrity.”

This definition is nearly identical to that of an electronic signature, with one key difference: while electronic signatures are linked to natural persons, electronic seals are linked to legal entities.

A digital signature allows the identification of an individual (with full name, tax code, etc.), while an electronic seal allows identification of an organization through its business name, VAT number, or tax ID.

Like signatures, seals can offer different levels of security and legal standing. An Advanced Electronic Seal is equivalent to an advanced electronic signature, while a Qualified Electronic Seal is defined as "an advanced electronic seal created by a qualified seal creation device and based on a qualified certificate for electronic seals," issued by a trusted service provider. This is similar to how a Qualified Electronic Signature works.

Advanced vs Qualified Electronic Seal

According to eIDAS, an Advanced Electronic Seal (AdESeal) must meet the following four criteria:

• It is uniquely linked to the seal creator;

• It can identify the seal creator with a high level of certainty;

• It is created using data under the sole control of the seal creator;

• It is linked to the sealed data in such a way that any subsequent changes can be detected.

Like an advanced electronic signature, an advanced seal can serve as evidence in legal proceedings, but its legal effect is determined by the court on a case-by-case basis.

The Qualified Electronic Seal (QeSeal), on the other hand, has the same legal value as a handwritten signature.

When applied by a legal entity, it guarantees the document's association with that entity. Only the qualified seal benefits from the presumption of data integrity and origin authenticity.

A QeSeal is created using a device equipped with a qualified certificate issued by a trusted provider accredited by the competent authority (in Italy, this is AgID).

Per Article 35 of eIDAS, a QeSeal issued in one EU Member State is automatically recognized across all other Member States.

Is a Qualified Seal the Same as a Digital Signature?

While the electronic seal is essentially the digital signature of a legal entity, there is a key legal distinction between a document signed by a person and one sealed by a company.

Traditionally, a handwritten signature serves three functions:

• Indicative function – it identifies the person signing;

• Evidentiary function – it proves the origin and authenticity of the document;

• Declarative function – it shows intent or assumption of responsibility.

The qualified seal undoubtedly fulfills the first two functions (indicative and evidentiary). However, eIDAS is not explicit about its declarative function, which is instead governed by national laws.

So, while the seal does prove the origin and integrity of a document, it does not necessarily indicate the intent of a specific individual.

That said, trust service providers are required to associate each legal entity’s certificate with a physical person. As a result, the qualified electronic seal is substantially equivalent to a qualified electronic signature. This is also reflected in Italy’s CAD (Digital Administration Code), which refers to qualified seals in the same context as qualified electronic signatures.

When should you use an Electronic Seal?

According to AgID:

"While a signature can identify an individual by name, tax ID, etc., a seal can identify a legal entity, but not the person who physically generated it."

For contracts, authorizations, and other documents requiring individual commitment, the qualified electronic signature of a legal representative is the appropriate tool.

The electronic seal, on the other hand, is ideal for standardized and automated documents, such as:

• Electronic invoices and certified email receipts

• Company certificates and business registry extracts

• Tax returns

• Medical records

• Quotes, project documents, and internal communications

• Digital contracts

• Certificates and diplomas

• Shipping and delivery documents

• Creative works and intellectual property proofs

Because seals can be applied without continuous human intervention, they are perfect for automated workflows via APIs.

Openapi’s Qualified Electronic Seal Service allows you to automatically apply QeSeals to large volumes of documents, directly from your software, management systems, or websites.