Public Works Tender: Compliant Electronic Signature in 2026

The building and civil engineering (BTP) sector represents one of the most active sectors in public procurement: in France, public contracts in construction account for more than 80 billion euros annually according to data from the Legal Affairs Directorate (DAJ) of the Ministry of Economy. Yet complete dematerialisation of these procedures remains an ongoing project for many companies in the sector. Since 1 October 2018, public contracts exceeding €25,000 excluding VAT must be submitted and processed compulsorily via electronic platforms. In 2026, regulatory maturity requires strengthened compliance, particularly around qualified electronic signature. This article guides you through the legal obligations, best practices and concrete solutions to secure your public BTP contracts thanks to electronic signature.

Why dematerialisation is essential in public works tenders

The regulatory framework that imposes digitalisation

The Public Procurement Code (CCP), which came into force on 1 April 2019, consolidated all texts relating to public contracts and concession contracts. It incorporates dematerialisation requirements from European Directives 2014/24/EU (public procurement) and 2014/25/EU (special sectors). In practice, since 2018 for public buyers and bidding companies, the entire document chain — submission of applications, transmission of technical and administrative documents, signature of commitment acts — must pass through electronic channels.

The buyer profiles (platforms such as PLACE, AWS-Achat, Maximilien or e-Bourgogne) centralise these flows. Article R. 2132-7 of the CCP explicitly states that "consultation documents are made available to economic operators on the buyer profile". Electronic signature intervenes at several stages: signature of the commitment act by the selected bidder, signature of amending acts (amendments), but also signature of reception reports and work situations in certain contractual configurations.

Specific challenges in the construction sector

Construction presents particular features that complicate dematerialisation:

• Volume and diversity of stakeholders: a works contract can involve a public client, a project manager, one or more main contractors, declared subcontractors and co-contractors as part of a temporary joint venture (GME).
• Multiple and technical documents: General Conditions of Performance, General Conditions of Administration, DC1, DC2, DC4, tax and social certificates, first-demand bank guarantees (GAPD), execution plans… Each document may require a signature or electronic visa.
• Tight timelines: open calls for tenders impose minimum deadlines for receipt of bids (25 days in standard procedure, reducible under certain conditions). Any delay due to signature malfunction can result in bid rejection.

To understand the fundamentals before addressing the sector-specific regulatory component, the complete guide to electronic signature establishes the essential terminological and legal foundations.

Levels of electronic signature applicable to public works tenders

Simple, advanced or qualified signature: what requirement for construction?

The eIDAS Regulation (No. 910/2014) distinguishes three levels of electronic signature, and French regulations on public contracts do not treat them uniformly. The Order of 12 April 2018 relating to electronic signature in public contracts establishes the technical framework applicable in France.

According to this Order:

• Advanced electronic signature based on a qualified certificate constitutes the minimum level required for signature of the commitment act.
• Qualified electronic signature within the meaning of eIDAS (created using a qualified signature creation device and based on a qualified certificate) offers the highest presumption of reliability and is recommended for complex contracts or significant amending acts.

It is crucial to understand that simple electronic signature (a simple click or a ticked box) is insufficient for contractual documents in public contracts. Certification service providers issuing qualified certificates in France are listed on the national trusted list (LOTL) published by ANSSI and accessible on the official portal of the European Union.

To go further on the distinctions between these levels, the guide on eIDAS Regulation 2.0 details the developments introduced by the new regulation and their implications for French companies.

Electronic certificates and their compliance

The qualified certificate must be issued by a qualified trust service provider (PSCQ) appearing on the European trusted list. In practice, for construction, this means:

1. Obtaining a personal or professional certificate from a PSCQ (ChamberSign, Certigna, DocuSign France, etc.).
2. Verifying compatibility of the signature format with buyer profiles: XAdES, CAdES and PAdES formats are the most common, in compliance with ETSI standards EN 319 132 (XAdES) and EN 319 122 (CAdES).
3. Configuring the workstation with necessary drivers and middleware, particularly for keys on hardware cryptographic media (USB token or smart card).

An often overlooked point: certificate validity over time. To guarantee the probative value of documents signed beyond certificate expiration, qualified electronic timestamping is essential. It makes it possible to attest that the signature was affixed at a precise moment when the certificate was valid.

Dematerialisation of public works tenders: process and best practices

Structuring the document flow for bidders

For a construction company bidding for a public contract, dematerialisation requires reviewing its internal organisation. Here are the key stages of an optimised process:

Phase 1 — Monitoring and downloading the tender documents: The Tender Document Package is now entirely downloadable from the buyer profile. This stage generally does not require signature but may require registration (account creation) on the platform.

Phase 2 — Preparation of application documents: Forms DC1 (letter of application) and DC2 (applicant declaration) are to be completed electronically. Tax certificates (tax compliance, URSSAF certificate) are now delivered directly online. Electronic signature for companies covers frequent business use cases, including administrative acts.

Phase 3 — Signature of the commitment act: This is the critical stage. The commitment act (AE) or its equivalent in the DUME form (Single Procurement Document) must be electronically signed by the legal representative of the company or their delegate. In the case of a joint venture, each member of the venture signs the DC1 and the mandatary signs the AE.

Phase 4 — Bid submission: Submission takes place before the deadline indicated in the tender regulations. An electronically dated receipt acknowledgement constitutes proof of submission within the timeframe.

Pitfalls to avoid during dematerialisation

Experience of public buyers and construction companies reveals several recurring errors:

• Confusion between mandatary signature and individual signature: In a joint or solidarity venture, only the mandatary signs the commitment act. Co-contractors sign only the documents directly concerning them (DC1 for each).
• Signature format not accepted: Some buyer profiles do not accept all formats. It is imperative to check the technical specifications of the tender regulations before proceeding with signature.
• Expired or revoked certificate: Prior verification of certificate status via the OCSP mechanism (Online Certificate Status Protocol) prevents signature rejection.
• Absence of buyer counter-signature: For the contract to be legally formed, the public buyer must also electronically sign the contract and notify the successful bidder. The notification deadline triggers the start of contractual obligations.

For companies wishing to assess their return on investment before migrating to a dedicated electronic signature solution, the Certyneo ROI calculator allows you to objectify expected gains based on the volume of documents processed.

Integration of an electronic signature solution into the construction workflow

Selection criteria for a compliant platform

Faced with the plurality of solutions available on the market, public clients and successful bidders must select a platform meeting specific criteria for the public contracts context:

1. eIDAS compliance: Native support for advanced and qualified signatures, integration with PSCQ referenced on the European trusted list.
2. Standard signature formats: Support for PAdES for PDFs (most common format in public contracts), XAdES for XML documents, and CAdES for binary files.
3. Traceability and audit trail: Detailed audit log, qualified timestamping, reliable archiving compliant with the NF Z 42-013 standard.
4. Interoperability: Ability to interface with buyer profiles via APIs or standardised exchange protocols.
5. Multi-signer management: Essential for company joint ventures or contracts involving multiple levels of internal validation.

The comparison of electronic signature solutions provides a comparative analysis grid of the main platforms available in France, with their respective strengths for the B2B and public procurement context.

Subcontracting and electronic signature: a chain to secure

Law No. 75-1334 of 31 December 1975 relating to subcontracting requires prior declaration of subcontractors and approval of their payment conditions by the client. In a dematerialised context, the transmission of the electronically signed DC4 (subcontracting declaration) fits into this legal framework.

Electronic signature also secures:

• Monthly work situations and their transmission for approval to the project manager then payment by the client.
• Reception reports (with or without reservations), fundamental acts that trigger the start of legal guarantees (completion, two-year and ten-year liability).
• Amending acts during execution, which must comply with the substantial modification thresholds defined in Article R. 2194-1 of the CCP.

Companies already equipped with an existing solution and wishing to benefit from better integration can consult the Certyneo migration offer for a transition without document continuity disruption.

Legal framework applicable to dematerialised public works contracts

Dematerialisation of public works contracts is part of a complex body of law, articulating national and European law. Here are the fundamental texts that any company in the sector must master.

Public Procurement Code (CCP) — Came into force on 1 April 2019, it codifies Ordinances No. 2015-899 and No. 2016-65. Articles R. 2132-1 to R. 2132-14 govern the methods of making consultation documents available and electronic submission of bids. Article R. 2182-3 requires electronic signature of the commitment act for formalised contracts.

Order of 12 April 2018 — Issued in application of Decree No. 2016-360, it specifies the conditions for using electronic signature in public contracts. It requires the use of a qualified certificate within the meaning of eIDAS Regulation and signature formats compliant with ETSI standards.

eIDAS Regulation No. 910/2014 — This European regulation, directly applicable in French law, establishes the legal framework for electronic signatures, electronic seals, electronic timestamps and authentication services. Qualified electronic signature benefits from a presumption of reliability equivalent to handwritten signature (Article 25, paragraph 2). eIDAS Regulation 2.0 (EU Regulation 2024/1183), currently being deployed, will strengthen interoperability requirements via the European digital identity wallet (EUDIW).

Civil Code, Articles 1366 and 1367 — Article 1366 establishes the principle of equivalence between electronic writing and paper writing, subject to identification of the author and guarantee of integrity. Article 1367 defines reliable electronic signature as one "which consists in the use of a reliable identification procedure guaranteeing its link with the act to which it attaches".

ETSI standards — ETSI standards EN 319 132 (XAdES), EN 319 122 (CAdES) and EN 319 102 (PAdES) define the technical profiles of advanced and qualified electronic signatures. They are made mandatory by the 2018 Order for public contracts.

GDPR No. 2016/679 — Dematerialisation involves the processing of personal data (identity of signers, electronic certificates). Public buyers and platform operators have the status of data controllers or processors depending on the configurations. Obligations regarding retention periods, right of access and data minimisation apply fully.

NIS 2 Directive (2022/2555/EU) — Transposed into French law by Law No. 2023-703 of 1 August 2023, it imposes strengthened cybersecurity requirements on essential and important entities, categories that may include operators of public procurement platforms and some major public works clients. Security incidents affecting signature systems must be reported to ANSSI.

Legal risks in case of non-compliance: A signature affixed with a non-qualified certificate or in a non-compliant format can lead to irregularity of the bid and its rejection. During the execution phase, a commitment act or amendment signed without complying with regulatory requirements exposes the company to a challenge of the document's probative value, or even nullity of the act under Articles 1366 and 1367 of the Civil Code.

Use cases: electronic signature in action in construction

Scenario 1 — A construction SME managing 40 calls for tenders per year

An SME specialising in finishing works (approximately 80 employees, specialising in aluminium joinery and glazing) responded until 2024 to about forty public calls for tenders per year by combining paper processes and scanned document submissions. The manager and commercial director had to affix handwritten signatures to the commitment act, digitise documents and deposit them on buyer profiles, with frequent risk of format errors or deadline overruns.

After deployment of a qualified electronic signature solution integrated with their commercial management software, the time for preparing and signing the administrative file fell from 4 hours to less than 45 minutes. Systematic traceability (qualified timestamping, audit log) reduced disputes related to proof of submission within deadlines by 90%. The rate of bids rejected for formal defects fell to zero over the 18 months following deployment.

Scenario 2 — A temporary joint venture (GME) for an energy retrofit contract

Three companies — a thermal engineering office, a specialist in external insulation and a tertiary electrician — form a joint GME to respond to a retrofit contract for a public housing park estimated at €3.2 million excluding VAT. The procedure is an open call for tenders subject to the CCP with full dematerialisation.

The complexity lay in the need to collect DC1 signatures from each of the three members, located in different cities, then the signature of the commitment act by the designated mandatary. Thanks to a platform managing electronic signatures with multi-signer workflows with sequencing, the validation circuit was completed in less than 3 working hours, compared to 2 to 3 days with previous paper or email exchanges. The entire 47-document file was signed and submitted 72 hours before closure, eliminating any timeline risk.

Scenario 3 — A public client managing notification and execution of works contracts

A territorial authority managing a multi-year investment programme (about twenty active works contracts simultaneously, for an annual volume of approximately 15 million euros) undertook to dematerialise the entire contractual chain, from notification to reception reports.

Before complete dematerialisation, signing amendments required physical journeys between the technical department, legal department, elected signatory and the company. The average processing time for an amendment was 18 working days. After deployment of a solution integrating qualified electronic signature and digital signature delegation, this timeframe fell to 4 working days, a reduction of 78%. Automatic reliable archiving of signed documents in the authority's document information system also secured the preservation of evidence for possible audits by the regional audit office.

Conclusion

Dematerialisation of public works contracts is no longer optional: it is a structuring regulatory obligation, governed by the Public Procurement Code, eIDAS Regulation and the 2018 Order. In 2026, construction companies that have not yet adopted a qualified electronic signature solution face concrete risks: bids rejected for formal defects, missed deadlines, disputes over the probative value of contractual acts.

The good news: robust, compliant and easy-to-deploy solutions exist, including for SMEs. They allow you to secure every stage — from application to work completion — whilst significantly reducing administrative timescales and processing costs.

Certyneo supports you through this transition with an eIDAS-compliant platform, adapted to the multi-signer workflows specific to construction. Start your free trial or request a demonstration to discover how to effectively digitalise your public contracts.