Public Procurement Construction: Compliant Electronic Signature in 2026

The building and construction industry (BTP) represents one of the most active sectors in terms of public procurement: in France, public procurement in construction is worth over 80 billion euros annually according to data from the Legal Affairs Department (DAJ) of the Ministry of Economy. Yet full digitalisation of these procedures remains an ongoing challenge for many companies in the sector. Since 1 October 2018, public procurement contracts exceeding €25,000 (excl. VAT) must be submitted and processed via electronic platforms. By 2026, regulatory maturity requires reinforced compliance, particularly regarding qualified electronic signature. This article guides you through the legal obligations, best practices and concrete solutions to secure your construction public procurement contracts through electronic signature.

Why digitalisation is essential in construction public procurement

The regulatory framework imposing digitalisation

The Public Procurement Code (CCP), which came into force on 1 April 2019, consolidated all texts relating to public procurement and concession contracts. It incorporates digitalisation 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 documentation chain — submission of applications, transmission of technical and administrative documents, signature of commitment acts — must be conducted electronically.

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 shall be made available to economic operators on the buyer profile". Electronic signature occurs at several stages: signature of the commitment act by the successful bidder, signature of amending acts (amendments), but also signature of acceptance records and work progress reports in certain contractual configurations.

Specific issues in the construction sector

Construction presents particularities that complicate digitalisation:

• Volume and diversity of stakeholders: a works contract may involve a public authority, a project manager, one or more main contractors, declared sub-contractors and co-contractors within a temporary joint venture (GME).
• Multiple and technical documents: Technical Specifications, Administrative Clauses, DC1, DC2, DC4, tax and social certificates, first-demand bank guarantees (GAPD), execution plans… Each document may require a signature or electronic endorsement.
• Tight deadlines: open tender procedures impose minimum deadlines for receipt of tenders (25 days in standard procedure, reducible under certain conditions). Any delay due to signature malfunctions can result in the tender being deemed inadmissible.

To understand the fundamentals before addressing the sectoral regulatory aspect, the complete guide to electronic signature establishes the essential terminological and legal bases.

Electronic signature levels applicable to public procurement

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

Regulation eIDAS (No. 910/2014) distinguishes three levels of electronic signature, and French regulation on public procurement does not treat them uniformly. The Order of 12 April 2018 on electronic signature in public procurement sets 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 maximum reliability presumption 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 procurement. Certification service providers issuing qualified certificates in France are listed on the national trust list (LOTL) published by ANSSI and accessible on the official European Union portal.

To learn more about the distinctions between these levels, the guide to Regulation eIDAS 2.0 details the changes 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 trust 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 accordance with ETSI standards EN 319 132 (XAdES) and EN 319 122 (CAdES).
3. Configuring the workstation with the necessary drivers and middleware, particularly for keys on hardware cryptographic media (USB token or smart card).

One often-overlooked point: the validity over time of the certificate. To guarantee the evidential value of documents signed beyond certificate expiration, qualified electronic time-stamping is essential. It allows proof that the signature was affixed at a precise moment when the certificate was valid.

Digitalisation of construction calls for tender: process and best practices

Structure the document flow for bidders

For a construction company bidding for public procurement, digitalisation requires reviewing its internal organisation. Here are the key steps of an optimised process:

Phase 1 — Monitoring and downloading the Tender Documents: The Tender Documents package is now fully downloadable from the buyer profile. This step generally does not require signature but may require registration (account creation) on the platform.

Phase 2 — Preparation of candidacy documents: Forms DC1 (letter of candidacy) and DC2 (candidate declaration) must be completed electronically. Tax certificates (tax compliance, URSSAF certificate) are now issued 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 step. The commitment act (AE) or its equivalent in the DUME form (Single European 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 signs the DC1 and the representative signs the AE.

Phase 4 — Tender submission: Submission takes place before the date and time limit indicated in the Call for Tenders. An electronic receipt with time-stamp constitutes proof of submission within the deadline.

Pitfalls to avoid when digitalising

Experience from public buyers and construction companies highlights several recurring errors:

• Confusion between representative signature and individual signature: In a joint or solidary joint venture, only the representative signs the commitment act. Co-contractors sign only the documents directly concerning them (DC1 for each).
• Non-accepted signature format: Some buyer profiles do not accept all formats. It is essential to check the technical specifications of the Call for Tenders before proceeding with signing.
• Expired or revoked certificate: Prior verification of the certificate status via the OCSP mechanism (Online Certificate Status Protocol) prevents signature rejection.
• Absence of counter-signature by the buyer: 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 date 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

Given the plurality of solutions available on the market, both public authorities and successful bidders must select a platform meeting specific criteria for the public procurement context:

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

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

Sub-contracting and electronic signature: a chain to secure

Law No. 75-1334 of 31 December 1975 on sub-contracting requires prior declaration of sub-contractors and approval of their payment conditions by the public authority. In a digitalised context, the transmission of the signed DC4 (sub-contractor declaration) fits into this legal framework.

Electronic signature also secures:

• Monthly progress reports and their transmission for endorsement to the project manager and then payment by the public authority.
• Acceptance records (with or without reservations), fundamental acts that trigger the start date 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 offer to migrate to Certyneo for a seamless transition in document continuity.

Legal framework applicable to digitalised construction public procurement

The digitalisation of construction public procurement falls within a dense legal framework, articulating national and European law. Here are the fundamental texts that every company in the sector must understand.

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 tenders. Article R. 2182-3 requires electronic signature of the commitment act for formalised contracts.

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

Regulation eIDAS No. 910/2014 — This European regulation, directly applicable in French law, establishes the legal framework for electronic signatures, electronic seals, electronic time-stamps and authentication services. Qualified electronic signature benefits from a reliability presumption equivalent to handwritten signature (Article 25, paragraph 2). Regulation eIDAS 2.0 (Regulation EU 2024/1183), currently being rolled out, will strengthen interoperability requirements through 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 that "which consists of the use of a reliable process of identification guaranteeing its connection with the act to which it is attached".

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 procurement.

GDPR No. 2016/679 — Digitalisation involves the processing of personal data (identity of signatories, electronic certificates). Public buyers and platform operators have the status of controllers or processors depending on configurations. Obligations regarding storage duration, 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 reinforced cybersecurity requirements on essential and important entities, categories potentially including operators of public procurement platforms and certain large construction 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 may result in the irregularity of the tender and its elimination. During performance, a commitment act or amendment signed without respecting regulatory requirements exposes the company to challenge of the evidential value of the document, or even to nullity of the act under Articles 1366 and 1367 of the Civil Code.

Usage scenarios: electronic signature in action in construction

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

An SME specialising in secondary construction works (approximately 80 employees, specialised in aluminium joinery and glazing) responded until 2024 to around forty public calls for tender per year using a combination of paper processes and scanned document submissions. The manager and commercial director had to affix their handwritten signatures to the commitment act, scan the documents and submit them to buyer profiles, with a frequent risk of format errors or deadline delays.

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

Scenario 2 — A temporary joint venture (GME) for a thermal renovation contract

Three companies — a thermal engineering firm, a specialist in external insulation and a tertiary electrician — form a joint GME to bid for a thermal renovation contract for a social housing portfolio estimated at €3.2 million (excl. VAT). The procedure is an open call for tenders under the CCP with complete digitalisation.

The complexity lay in the need to collect signatures of the DC1 from each of the three members, located in different cities, then the signature of the commitment act by the designated representative. Using an electronic signature platform managing multi-signatory workflows with sequencing, the validation process was completed in less than 3 working hours, compared to 2 to 3 days with previous paper or email exchanges. The entire file of 47 documents was signed and submitted 72 hours before the deadline, eliminating any risk of delay.

Scenario 3 — A public authority managing notification and performance of works contracts

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

Before complete digitalisation, the signature of amendments required physical back-and-forth between the technical department, legal department, elected signatory and the company. The average processing time for an amendment was 18 working days. After deploying a solution integrating qualified electronic signature and digital signature delegation, this deadline fell to 4 working days, a reduction of 78%. Automatic evidential archiving of signed documents in the authority's document information system also secured the preservation of evidence for potential regional accounts chamber audits.

Conclusion

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

The good news: robust, compliant and easy-to-deploy solutions exist, including for SMEs. They make it possible to secure each stage — from candidacy to completion of works — while significantly reducing administrative delays and processing costs.

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