Electronic signatures for real-estate contracts: what is valid and how to use it

eIDAS: the framework that makes it valid across the EU

Electronic signatures in the European Union are governed by Regulation (EU) 910/2014, known as eIDAS, amended in 2024 to introduce the European Digital Identity Wallet. It is a regulation, not a directive: it applies the same way in Spain and in Estonia without transposition. In Spain it is complemented by Law 6/2020, which regulates certain aspects of electronic trust services.

eIDAS recognises three levels of signature, and it is worth keeping them apart:

• Simple electronic signature: any electronic data the signatory uses to sign. A signature drawn on a screen, for example.
• Advanced electronic signature: on top of that, it must be uniquely linked to the signatory, capable of identifying them, created with means under their sole control, and linked to the signed data so that any later change is detectable.
• Qualified electronic signature: an advanced signature created with a qualified device and based on a qualified certificate issued by a trust service provider.

The rule that matters in a dispute

eIDAS sets out two things worth being clear about. First: a signature cannot be denied legal effect or admissibility as evidence solely because it is electronic or because it is not qualified. Second: a qualified signature has the equivalent legal effect of a handwritten one.

In day-to-day terms: a simple or advanced signature is valid, but if someone disputes it you will have to prove who signed and that the document has not changed. With a qualified signature that argument starts in your favour. So the question is not “is an electronic signature valid?” but “how much proof do I need for this document?”.

What still needs a notary

Electronic signatures speed up everything around a sale, but they do not replace the notary where the law requires one. In Spain, a sale is formalised in a public deed before a notary so it can be entered in the Land Registry. In Estonia, the contract for the sale of real property is executed before a notary. What you can sign remotely is everything before that and everything that does not transfer ownership: the listing or brokerage agreement, the viewing authorisation, the internal paperwork of the deal.

Estonia: digital signing is the norm

Estonia has signed digitally with the ID card since 2002, and Mobiil-ID and Smart-ID followed. All three enable qualified signatures and are part of everyday life for any resident. The official id.ee portal explains how they work. For an Estonian agency, asking for a remote signature is the norm, not the exception, and clients expect to sign without travelling.

Which signature to use when

• Client in front of you, internal or low-risk document: a signature drawn on the agent’s phone screen. Fast and frictionless.
• Client at a distance, private document: signing by link with one-time-code verification, which records who signed, when and exactly which document.
• Maximum legal certainty, or documents you want to make watertight: a qualified signature. In Estonia, Smart-ID, Mobiil-ID or the ID card; in Spain, a qualified certificate such as the FNMT certificate or the electronic ID card.
• The property sale itself: a notary, in both countries.

You do not lose sales for lack of interest — you lose them to friction. Remote signing removes the friction of the last mile.

Traceability: your insurance in a dispute

What protects the agency is not the signature itself but the evidence around it: who signed, how their identity was verified, when, and on which exact version of the document. That evidence has to be archived with the contract, and the document locked against changes. If someone later disputes what was agreed, that is what you will show.

How signing works in Domuspace

The contracts and e-signature module, from the Professional plan, covers the whole flow, from template to archive:

• Sale and rental contracts for collaboration, exclusive or brokerage mandates. The exclusive template comes as standard, in Spanish and under Spanish law; for the rest you use your own templates in HTML or Word (.docx), which the administrator imports from a computer, marking where the client and property data go.
• In-person signing: the client signs with a finger on the agent’s phone screen, and the agent signs next.
• Remote signing, in Spain: the client receives a link, reads the document, requests a six-digit code by email and signs without creating an account. The link lasts 72 hours and can be resent up to twice a day.
• In Estonia, remote signing with eID through eID Easy, which returns the electronically signed PDF. Domuspace switches it on, it needs a template in Estonian, and it has a quota of 30 signatures a month on Professional and 70 on Extra.
• From the contract list you can see which are signed, pending, in draft or cancelled.
• Signed means closed: the document is locked against changes and archived in Contracts with its signatories and date, linked to the contact.

And the contract does not live on its own: the exclusive can be prepared from the plot itself on the map, with its cadastral reference, and every company document is organised by folders and permissions in the contracts archive.

Before you change how you sign

Review your templates with your legal adviser: the right type of signature depends on the document and on what you want to be able to prove later. Once that is clear, look at the plans or ask for a demo. If the exclusive is what you want to close, start with how to win it.

This article is for information only and does not constitute legal advice.