Level 3 · Qualified electronic signature

Qualified signature: the same effect as signing by hand

For transactions where there can be no doubt. The signer uses their qualified certificate, issued by a trust service provider that has verified their identity, and the document receives a qualified electronic time stamp. By law, it is equivalent to a handwritten signature throughout the European Union.

What it is and what sets it apart

A qualified electronic signature is an advanced signature created with a qualified device and based on a qualified certificate issued by a trust service provider that has verified the holder's identity; it is the only level the eIDAS Regulation equates in its own right with a handwritten signature and the one recognized as such in every Member State, which is why it is reserved for high-value transactions and procedures that require a qualified signature.

Content reviewed on 17 October 2026

Legal definition: Art. 3(12) of the eIDAS Regulation Advanced + qualified device + qualified certificate
Equivalence: Same effect as handwritten Art. 25(2) of the eIDAS Regulation
Scope: Recognized across the EU Art. 25(3) of the eIDAS Regulation
Identity verification: When the certificate is issued In person or remotely with equivalent assurance (Art. 24 eIDAS)
Valid providers: Those on the trusted lists Art. 22 eIDAS; searchable on the European Commission portal
Burden of proof in Spain: Falls on the challenger Art. 326.4 of the Spanish Civil Procedure Act (LEC)

Qualified certificate

Issued by a qualified trust service provider (QTSP).

Secure device

Smart card or Spanish electronic ID card (DNIe), USB token or cloud-held certificate.

Signing with AutoFirma

Works with certificates such as those from FNMT (Spain's national mint) via AutoFirma.

Qualified time stamp

Legal presumption that the date and time are accurate and the data intact.

When to use it

High-value transactions and demanding procedures

Shareholder agreements, letters of intent and pre-transaction contracts
Investment and asset purchase agreements
High-value financial agreements
Contracts with institutions that require a qualified signature
Documents that must be valid in other EU Member States
Filings with public authorities that require a qualified signature

How it works

Qualified signature with a certificate, step by step

KimoSign runs the workflow and keeps the evidence; the signature itself is created by the signer's own qualified certificate.

1 The document is preparedIt is uploaded to KimoSign and assigned to the signers who must use a certificate.
2 Notice and authenticationThe signer receives the link and authenticates with a one-time code by text message.
3 They sign with their certificateUsing their qualified certificate through AutoFirma, on a card, token or in the cloud.
4 Validation and sealThe certificate is validated and the document receives a qualified time stamp.
5 DeliveryAll parties receive the signed copy, immediately valid throughout the EU.

In context

Where qualified stands against the other levels

Comparison of simple, advanced and qualified electronic signatures under the eIDAS Regulation
Feature	Level 1 Simple	Level 2 Advanced	Level 3 Qualified
Security level	Basic	High	Highest
Signer identification	Not required: a click, a checkbox or an email confirmation is enough	Mandatory: one-time PIN by text message or email, handwritten stroke on screen	Qualified certificate issued by a trust service provider that has verified the signer's identity
Document integrity	Does not, on its own, guarantee the document stays unchanged	Any later change invalidates the signature	Any change invalidates it, backed by a qualified device and certificate
Evidence recorded	Date, time, IP address and email	Plus authentication method, time stamp and document fingerprint	Plus certificate data and a qualified time stamp
Legal value (eIDAS)	Valid; its weight as evidence depends on the audit trail	Valid, and carries considerable weight if challenged	Same legal effect as a handwritten signature throughout the EU
Typical uses	Terms of service, forms, internal policies	Commercial and employment contracts, NDAs, authorizations	High-value transactions, financial agreements, procedures that require a qualified signature

Typical scenarios

When there is no room for doubt

Family business · corporate transaction

Shareholder agreement signed from two cities

Before Getting all parties together to sign on paper forced the deal to be postponed twice.

After Each party signs with their qualified certificate from their own office. The document is sealed with a qualified time stamp and is valid immediately.

Financing · high-value agreement

The lender requires a qualified signature

Before The authorized representative had to travel to the branch to sign in front of an employee.

After They sign with their representative certificate through AutoFirma within the KimoSign workflow. The lender receives the signed document instantly.

Industrial group · subsidiary in another Member State

An agreement that must be valid in two countries

Before There were doubts about whether a Spanish electronic signature would be accepted by the foreign counterparty.

After With a qualified signature, recognition in the other Member State is provided for by the eIDAS Regulation itself.

Vocabulary

Qualified signature terms

Qualified certificate for electronic signatures: An electronic certificate that links signature validation data to a person and is issued by a qualified provider meeting the requirements of Annex I of the eIDAS Regulation.
Qualified trust service provider (QTSP): A supervised entity that has been granted qualified status by the national supervisory body and appears on its State's trusted list. Only a QTSP can issue qualified certificates and qualified time stamps.
Qualified signature creation device: Hardware or a service that protects the holder's signature creation data and meets the requirements of Annex II of the Regulation: smart cards, tokens or certified cloud signing services.
Trusted list: The official list, published by each Member State, of qualified providers and the services they are authorized to provide.
AutoFirma: The Spanish Government's electronic signature application, used to sign documents with certificates installed on the computer or stored on a card.

Frequently asked questions

What people ask us before they start

Is it really equivalent to a handwritten signature?

Yes. Article 25(2) of the eIDAS Regulation states that a qualified electronic signature has the equivalent legal effect of a handwritten signature. It is the only level to which the law grants that equivalence in its own right.

What certificate does the signer need?

A qualified certificate for electronic signatures issued by a provider on the EU trusted lists. In Spain the usual ones are the FNMT certificate or the electronic ID card (DNIe); there are also providers that hold it in the cloud.

How is the signer's identity verified?

The provider verifies it when issuing the certificate, in person or by remote identification methods offering equivalent assurance (Art. 24 eIDAS). That is why a qualified signature does not depend on what is checked at the moment of signing.

Is it valid in other countries?

Yes. Article 25(3) requires every Member State to recognize as qualified a qualified signature based on a qualified certificate issued in any of the others.

What procedural advantage does it give in Spain?

When a qualified trust service is used, the Spanish Civil Procedure Act presumes the document has the disputed characteristic, and the burden of proving otherwise falls on whoever challenges it (Art. 326.4 LEC).

Does it replace a notarized deed?

No. It is equivalent to a handwritten signature, not to a notary's attestation. Acts that the law requires in a public instrument (for example, the transfer of shares in a Spanish limited company or the purchase of a property to be entered in the Land Registry) still go through a notary.

Should it always be used?

No, and it is better not to: it adds an extra step for the signer. Keep it for documents where the law, the other party or the value of what is being signed demands it.

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Keep exploring

Qualified electronic signature with certificate and time stamp

A qualified electronic signature is an advanced signature created with a qualified device and based on a qualified certificate issued by a qualified trust service provider. Under Article 25(2) of the eIDAS Regulation, it has the same legal effect as a handwritten signature.

KimoSign supports signing with qualified certificates on a smart card, DNIe, USB token or in the cloud through AutoFirma, with prior PIN authentication, a qualified electronic time stamp and recognition in every Member State.