Property Purchase Agreement & Electronic Signature

The digitalisation of the property sector has accelerated considerably since 2020. Today, more than 60% of property professionals in France use electronic signatures for their preliminary contracts, according to estimates by the National Federation of Real Estate (FNAIM). Yet many questions remain: does an electronically signed purchase agreement or promise of sale have the same legal value as a paper deed? What level of signature should be required? What is the notary's role in this process? This article provides clear, expert answers grounded in French law and the European eIDAS regulation.

What the law says about electronic signatures for property purchase agreements

The legal value of electronic documents under French law

Since the law of 13 March 2000, codified in articles 1366 and 1367 of the Civil Code, electronic documents have been recognised as equivalent to paper documents, subject to two cumulative conditions: reliable identification of the person from whom it originates, and guarantee of the document's integrity. The property purchase agreement, which under French law constitutes a preliminary synallagmatic contract binding both parties irrevocably subject to suspensive conditions, can therefore be concluded in electronic form.

However, the nature of this deed requires particular precautions. A purchase agreement is not a simple order form: it can commit sums of several hundred thousand euros and must satisfy strict pre-contractual information requirements (Alur law, Macron law, mandatory property inspections). The robustness of the signature used directly determines its probative value in case of dispute.

The three levels of eIDAS signatures applied to property transactions

Regulation eIDAS No. 910/2014 distinguishes three levels of electronic signatures, whose relevance varies according to the type of property deed:

Simple electronic signature (SES): sufficient for low-value information documents or search mandates, it is generally insufficient for a purchase agreement due to the high risk of challenge.

Advanced electronic signature (AES): this is the level recommended by professional practice for purchase agreements under private deed. It is based on strong authentication of the signatory (generally via an OTP code sent to the mobile phone and documentary identity verification). It allows unique identification of the signatory, detection of any document alteration after signature and commitment of the signatory's responsibility.

Qualified electronic signature (QES): mandatory for notarised deeds, it is based on a qualified certificate issued by a trust service provider (TSP) listed on the EU Trusted List. For electronic authentic deeds (EAD), notaries have since 2008 had access to a specific qualified signature creation device managed by the Supreme Council of Notaries (CSN) via the REAL infrastructure (Electronic Network of Authorities and Notaries).

Purchase agreement under private deed vs authentic deed: two distinct regimes

It is essential to distinguish between two legally different situations:

The purchase agreement under private deed, drafted and signed directly between individuals or via a property professional (estate agent, notary in advisory capacity only), can be signed with an advanced electronic signature. No law requires qualified signature here for ordinary properties (except for sales of future properties – VEFA – or certain properties subject to special regimes).

The unilateral promise of sale (or promise to purchase), when registered with the tax administration within ten days (article 1589-2 of the Civil Code, on pain of nullity for certain promises), requires special attention: registration may be carried out in dematerialised form, but the authenticity of the signature must be beyond dispute.

The authentic deed of sale (final deed signed at the notary's office), requires mandatory qualified electronic signature of the notary, in accordance with decree No. 2005-973 of 10 August 2005 and subsequent texts relating to the electronic authentic deed.

The central role of the notary in property electronic signatures

The electronic authentic deed (EAD): a silent revolution

Since 2008, French notaries have been able to draw up fully dematerialised authentic deeds. By 2025, more than 95% of property sale deeds at notaries' offices are drafted in electronic form according to CSN data. The electronic authentic deed (EAD) offers major advantages: enhanced probative force, opposability to third parties, secure storage in the MINUTIER CENTRAL system (central digital archiving).

The notary applies their qualified electronic signature using a personal encrypted USB key and PIN code. This signature is based on a qualified certificate issued by the notary chamber, compliant with the ETSI EN 319 132 standard for XAdES signatures, or CAdES/PAdES depending on the document format.

Remote appearance: notarial remote signing

The ELAN law of 23 November 2018 (article 20) and decree No. 2020-395 of 3 April 2020 legalised remote appearance before a notary in France, also called "remote notarial deed" or "remote signing". This procedure allows the buyer and/or seller to sign the authentic deed without physically travelling to the notary's office, via a secure video conferencing platform approved by the CSN.

In practice: the notary is present at the office, the client(s) appear remotely via video. Identity verification is carried out in real time, and signatures are applied electronically via a secure process. This development has considerably streamlined transactions, particularly for buyers residing abroad or in remote regions.

Signing the purchase agreement at the estate agent's office or online

In common practice, the purchase agreement is frequently signed at the estate agent's office or online, outside any notarial framework. In this case, SaaS electronic signature platforms such as Certyneo for property play a decisive role: they must guarantee:

• Identity verification compliant with eIDAS (documentary verification + facial liveliness for advanced levels)

• Qualified timestamping of the signed document

• Complete audit trail (logs, IP addresses, document fingerprints)

• Secure storage of signature evidence

The complete guide to electronic signatures details the technical criteria to verify when choosing your solution.

Practical procedure: signing a purchase agreement online step by step

Preparing the documentary file

Before any signature, the seller must compile the technical diagnostic file (TDF) including in particular: energy performance certificate (EPC), lead exposure risk assessment (LERA) if the property predates 1949, condition of electrical and gas installations if over 15 years old, statement of risks and pollution (SRP), and asbestos assessment for building permits prior to July 1997.

These documents must be annexed to the purchase agreement and included in the documentary package submitted for electronic signature. A professional platform must enable signature of multi-page documents with annexes, and generate a single probative file including the entire file.

The electronic signature journey

An advanced electronic signature journey for a purchase agreement typically follows these steps:

• Upload and preparation: the professional imports the agreement and its annexes onto the platform, places signature and initial zones page by page.

• Signatory invitation: buyer(s) and seller(s) receive a secure link by email.

• Identity verification: depending on the signature level, the signatory uploads an identity document and performs a selfie or dynamic facial recognition.

• Reading and initials: the signatory reviews the document, initials each page (or accepts automatic scrolling).

• OTP code: a one-time code is sent by SMS to the signatory's verified phone number.

• Signature application: the signature is cryptographically linked to the document, timestamped and recorded with the audit trail.

• Archiving: all parties receive a copy of the signed agreement in PDF/A format with its proof report.

Withdrawal period and electronic signature

The SRU law (article L. 271-1 of the Construction and Housing Code) grants the non-professional buyer a 10-calendar-day withdrawal period from notification of the preliminary contract. In the context of electronic signature, this notification may be carried out by dematerialised means (electronic registered mail or secure traceable transmission), provided that the acknowledgement of receipt is probative and timestamped. The signature platform must therefore integrate an electronic registered mail function compliant with the ETSI EN 319 532 standard.

Note that the period runs from the day following the first presentation of the registered letter, not from its signature. Choosing an integrated solution that manages both signature and electronic registered notification simultaneously considerably simplifies this critical step.

Choosing the right electronic signature solution for property

Platform selection criteria

Facing the multiplication of offers on the market (DocuSign, Yousign, Universign, Certyneo and others), property professionals must evaluate platforms on specific criteria:

Regulatory compliance: the platform must be certified by an accredited body (ANSSI, BSI, LSTI…) and be listed or rely on TSPs listed on the EU Trusted List. Verify ISO 27001 certifications, eIDAS advanced and/or qualified level depending on your needs.

User experience: in property, signatories are often individuals unfamiliar with electronic signatures. The journey must be intuitive, available on mobile, and accompanied by contextual help.

Industry integration: ideally, the solution integrates with your property management software (Périclès, Immofacile, iadmin, Apimo…) via REST API or native connectors.

Probative archiving: beyond signature, secure storage of signed documents for statutory periods (30 years for a sale deed) is a major issue. Some platforms offer an integrated digital safe compliant with the NF Z 42-020 standard.

Support and SLA: for transactions with high financial stakes, support availability (ideally 24/7) and availability SLA above 99.9% are prerequisites.

To objectively compare market solutions, consult our comparison of electronic signature solutions.

ROI of electronic signatures in property agencies

Adoption of electronic signature generates measurable gains for property professionals:

• Reduction in signature delay: a traditional purchase agreement requires on average 5 to 10 days of coordination to bring the parties together; electronic signature reduces this delay to 24-48 hours in the majority of cases.

• Decrease in logistical costs: printing, registered mail, physical archiving represent between £15 and £30 per file depending on agencies.

• Reduction in incomplete file rate: platforms require completion of all required fields before signature, eliminating forgotten initials or signatures on certain pages.

• Improved customer experience: the ability to sign from home or office, without travel, is a differentiating sales argument.

Calculate your personalised return on investment with our electronic signature ROI calculator.

Legal framework applicable to electronic signatures of property purchase agreements

Founding texts

Civil Code, articles 1366 and 1367: these two articles form the foundation of French law on electronic evidence. Article 1366 provides that "an electronic document has the same probative force as a document on paper support, provided that the person from whom it originates can be duly identified and it is established and preserved in conditions designed to guarantee its integrity". Article 1367 specifies the validity conditions for electronic signatures: reliability of signatory identification and guarantee of deed integrity.

eIDAS Regulation No. 910/2014 of the European Parliament: this regulation applies directly in French law and defines three levels of signature (simple, advanced, qualified) and requires mutual recognition of qualified electronic signatures within the European Union. In 2024, the eIDAS 2.0 revision (EU Regulation 2024/1183) strengthened digital identity requirements with the introduction of the European digital identity wallet (EUDI Wallet), scheduled for rollout in France during 2026.

Decree No. 2005-973 of 10 August 2005: relating to the electronic authentic deed, it establishes the basis for notarial qualified signature and the REAL infrastructure. Supplemented by CSN orders governing security conditions and signature creation devices used by notaries.

ELAN law of 23 November 2018 (article 20) and decree No. 2020-395 of 3 April 2020: legalise remote appearance before a notary, establish conditions for notarial videoconference and specify the notary's obligations regarding remote identity verification.

Article L. 271-1 of the Construction and Housing Code: governs the 10-day withdrawal period for non-professional buyers and notification methods (applicable by electronic means subject to traceability conditions).

ETSI EN 319 132 standard: European standard defining technical requirements for advanced electronic signatures (XAdES) used in professional and institutional exchanges.

GDPR No. 2016/679: the collection of biometric data (facial recognition) in the context of identity verification for electronic signatures constitutes processing of special category personal data (article 9 GDPR). The controller must have explicit legal basis and conduct prior impact assessment (DPIA). Electronic signature providers must guarantee GDPR compliance of their identity verification processing.

Legal risks in case of non-compliance

Use of non-compliant electronic signature on a purchase agreement exposes one to several risks: nullity of the preliminary contract for formal defect in case of dispute, inability to assert signature proof before civil courts, professional liability of the estate agent or notary for breach of advisory duty, and loss of deposits or immobilisation fees if the agreement is contested. It is essential to ensure that the chosen platform provides a proof report (or "proof file") archived and opposable to third parties, including: unique document identifier, qualified timestamp, cryptographic fingerprint (SHA-256 hash or higher), journal of actions by each signatory.

Usage scenarios: electronic signature of purchase agreements in practice

Scenario 1 — An independent property agency handling 150 to 200 purchase agreements per year

An intermediate-sized property agency with 5 to 8 negotiators previously managed all its purchase agreements in paper format. Each file required on average 45 minutes of administrative work (printing, initials, registered mail, filing), plus frequent follow-ups to obtain signatures from buyers and sellers not residing locally.

After deploying an advanced electronic signature solution compliant with eIDAS, the agency observed a reduction in average signature collection time from 8 days to less than 48 hours. The rate of incomplete files returned (forgotten initial, missing page) fell from 22% to less than 2%. The logistical cost per file (paper, registered mail, archiving) decreased by 70%. The agency also marketed this modernisation as a sales argument to a customer base of first-time buyers and active online investors.

Scenario 2 — A property developer managing VEFA on multiple programmes simultaneously

A property developer launching 3 to 5 residential programmes in parallel, representing between 80 and 150 reservations per year, faced complex geographical coordination challenges: local and regional buyers and investors living abroad, associated with coordinating notaries across multiple offices.

By deploying a qualified electronic signature solution integrated into their CRM via API, the developer was able to centralise management of reservation contracts and electronic authentic deeds. The time to finalise VEFA sale deeds was reduced by 30% on average. Documentary compliance (mandatory technical annexes, descriptive notices) was automated via pre-configured templates. The developer also reduced travel expenses related to signatures by 45% over one financial year, using remote notarial signing for expatriate clients. Our AI contract generator can also facilitate drafting of standard documents in this context.

Scenario 3 — A network of property agents without physical office

A network of independent agents operating exclusively digitally, without physical office, needed a fully mobile electronic signature solution, accessible from smartphone or tablet, to finalise preliminary contracts directly during viewings or remotely.

By adopting a mobile-first SaaS platform with integrated identity verification via NFC (reading the chip on identity card or biometric passport) and advanced signature via OTP SMS, the network was able to reduce its rate of abandonment between accepted offer and signed agreement from 18% to less than 5%. Processing speed and smooth customer journey improved the recommendation rate (NPS) by +22 points over 12 months. Agents also benefited from access to standardised contract templates and legally up-to-date, reducing risks of non-compliant drafting.

Conclusion

The electronic signature of property purchase agreements is today a legally solid reality, provided appropriate signature levels are respected for the type of deed: advanced signature for preliminary contracts under private deed, qualified signature for notarial authentic deeds. The eIDAS regulation and articles 1366-1367 of the Civil Code provide a robust framework, strengthened by the increasing uptake of notarial remote signing and compliant SaaS platforms.

Choosing the right solution is decisive: user experience, regulatory compliance, probative archiving and industry integrations are the differentiating criteria. Certyneo offers an electronic signature solution specifically tailored to property challenges, eIDAS compliant, certified and supported by expert teams.

Ready to digitalise your purchase agreements with full security? Start your free trial on Certyneo or contact our team for personalised support.