Electronic signatures in Spain: eIDAS, Law 6/2020 and what you can sign online

Spain is a country where many people already sign online: individuals and companies commonly use digital certificates to deal with the tax office and other public bodies. In private business, the starting point is even simpler. Spanish contract law is built on freedom of form, so most agreements can generally be concluded — and signed — electronically.

Are electronic signatures legal in Spain?#

Yes. Several laws work together:

• eIDAS Regulation (EU) No 910/2014, as amended by Regulation (EU) 2024/1183, applies directly. An electronic signature can't be denied legal effect or admissibility as evidence just because it is electronic, and a qualified electronic signature has the same legal effect as a handwritten one. See our guide to electronic signatures in the European Union for the EU-wide framework.
• Law 6/2020 of 11 November on certain aspects of electronic trust services (Ley 6/2020, reguladora de determinados aspectos de los servicios electrónicos de confianza) supplements eIDAS in Spain and replaced the earlier Electronic Signature Law 59/2003.
• The Civil Code (Código Civil). Under article 1278, contracts are binding whatever form they are concluded in, as long as the essential conditions for validity are met.
• Law 34/2002 on information society services and electronic commerce (LSSI). It confirms that contracts concluded electronically are valid and that, where the law requires a contract to be in writing, this is generally met if it is contained in an electronic medium.

On evidence, Spanish procedural rules give documents backed by qualified trust services a stronger presumption of authenticity. With other electronic signatures, the party relying on the signature may need to prove its authenticity if it is challenged — which is where good evidence comes in.

Types of electronic signature in Spain#

Spain uses the three eIDAS levels:

• Simple electronic signature (firma electrónica simple) — for example, a typed or drawn signature submitted through a secure link.
• Advanced electronic signature (firma electrónica avanzada) — uniquely linked to and capable of identifying the signer, with later changes detectable.
• Qualified electronic signature (firma electrónica cualificada) — based on a qualified certificate from a qualified trust service provider and created with a qualified device.

Signkoi provides simple electronic signatures with strong evidence. It does not create advanced or qualified signatures.

Documents that often need more than a simple e-signature#

• Real estate. A private contract to buy property can be valid between the parties, but to register the transfer in the Land Registry (Registro de la Propiedad) a public deed (escritura pública) signed before a notary is generally needed.
• Family and succession law. The LSSI rules on electronic contracts expressly don't apply to contracts governed by family law and succession law.
• Contracts that need a notary, registrar or public authority. Under the LSSI, these follow their own specific legislation — for example, many corporate acts that must be recorded in a public deed and registered in the Commercial Registry.
• Wills. A will is generally either handwritten in full by the testator (testamento ológrafo) or made before a notary.
• Dealings with public administrations. Public procedures have their own rules on identification and signature, under Law 39/2015 on common administrative procedure. They typically accept specific systems such as digital certificates or Cl@ve, rather than a general e-signature.

Collecting stronger evidence with simple e-signatures#

If a simple electronic signature is ever challenged, you will generally want to show who signed, that they meant to sign and that the document hasn't changed since:

• Audit trail. Record each step — sent, opened, signed — with time, IP address and browser.
• Identity checks. For important agreements, ask signers to enter an access code you share separately, or an email one-time code.
• Integrity. A tamper-evident seal on the final PDF makes later changes detectable, and a trusted timestamp records when it was signed.
• Storage. Keep the signed PDF and its certificate of completion together with your records.

How to send a document for signature in Spain with Signkoi#

1. Upload your PDF — a contract, a quote (presupuesto) or an order form.
2. Add your signers by name and email, and set a signing order if one should sign before another.
3. Place the fields — signature, initials, date, text or checkboxes.
4. Add an access code or email one-time code for sensitive documents.
5. Set reminders and an expiry date, then send.

Recipients sign in their browser without creating an account, and the signing pages are available in Spanish. When everyone has signed, the PDF is sealed and timestamped, and you receive a certificate of completion that summarises the audit trail. Anyone holding the PDF can check that it is unchanged at signkoi.com/verify. For other countries, see our e-signature legality overview.

FAQ#

Is a contract signed electronically valid in Spain?#

Generally yes. Spanish law follows the principle of freedom of form, and eIDAS prevents an electronic signature from being refused legal effect just because it is electronic. Exceptions apply for documents that need a public deed or fall under family or succession law.

Do I need a digital certificate to sign contracts in Spain?#

Not for most private agreements. Digital certificates are widely used for dealings with public bodies, and a qualified signature can be useful for high-stakes documents. For many everyday contracts, a simple electronic signature with good evidence is commonly used.

Can I use Signkoi for filings with Spanish public bodies?#

Generally not. Public administrations set their own accepted identification and signature systems, such as digital certificates or Cl@ve. Check the requirements of the specific body or procedure.

This article is general information, not legal advice. Spanish law and its interpretation can change, and the right signing method depends on the document and the circumstances. For an important or regulated document, talk to a qualified lawyer (abogado) or notary in Spain.