Electronically signing a contract: value, steps, pitfalls

Signing a contract electronically is now as legal, recognized and enforceable as a handwritten signature — provided you respect a few simple rules from the European eIDAS regulation and the French Civil Code. Whether you are a startup signing your first permanent contracts remotely, a consulting firm managing international NDAs, or a merchant sending a quote, this guide explains concretely how to sign a contract electronically in 2026, what legal value this produces, and what are the classic pitfalls to avoid.

The legal framework in one minute

The electronic signature of a contract is based on three fundamental texts. The European eIDAS regulation (EU n°910/2014) defines three levels: simple (SES), advanced (AES) and qualified (QES). Article 1367 of the French Civil Code recognizes the electronic signature as a means of proof equivalent to the handwritten signature, provided that it identifies the signatory and guarantees the integrity of the document. The law of March 13, 2000 paved the way by introducing electronic signatures into French law.

Can all contracts be signed electronically?

Yes for the vast majority: CDI, CDD, NDA, commercial agreements, residential leases and commercial leases, mandates, simple powers of attorney, quotes, purchase orders, general conditions. Some limiting exceptions: private deeds relating to family law (marriage contract, PACS, donations) and certain authentic deeds (real estate sale at the notary) which require either a qualified signature (QES) or physical presence. If in doubt, consult article 1175 of the Civil Code.

Step 1: choose the right signature level

The choice depends on the risk associated with the contract. For a low to medium-stakes contract (quote, purchase order, standard NDA, certificate): the SES level (simple signature by click + email link) is sufficient. For a high-stakes contract (permanent contract, lease, 5-digit commercial contract and more): choose AES with OTP SMS for more robust identification. For a regulated act (notary, lawyer subject to article 66-3-3, public contract above the threshold): QES mandatory.

Step 2: prepare the document

Make sure the contract is finalized (no clauses to negotiate) and in PDF format. Avoid editable formats (Word) sent to sign: any post-signing modification invalidates the proof of integrity. Ideal: convert to PDF/A (ISO 19005 format, optimized for archiving) before sending. Certyneo does this automatically upon upload.

Step 3: precisely identify the signatories

Enter the name AND email of each signatory. Double-check this information: an email error can invalidate the signature if the email belongs to someone other than the one named in the contract. For a multi-party contract, activate sequential mode (signature one after the other, everyone sees the previous signatures) rather than parallel, unless the signatories are completely independent. The audit trail will document the chronological order.

Step 4: signature and proof

Each signatory receives an email with a personal link, consults the document in full screen, accepts the conditions of use of the platform, then validates (in AES mode, enters their OTP received by SMS). The final PDF includes a digital certificate, an SHA-256 fingerprint, a certified timestamp, and an audit trail listing each action. These 4 elements constitute your opposable proof — kept for a minimum of 10 years for commercial acts (article L. 123-22 of the Commercial Code).

The 5 traps to avoid

Trap 1: use a scanned signature image (no value). Trap 2: send a Word instead of a PDF (modifiable afterwards). Trap 3: not checking the signatory's email (risk of receipt by a third party). Trap 4: choose the SES level for a commercial lease at €200k/year (undersized, AES minimum). Trap 5: delete the audit trail after signature (without it, the proof is weakened). Certyneo automatically keeps all evidence for 10 years.

Opposability in the event of a dispute

A contract signed electronically at AES or QES level is accepted by French and European jurisdictions. In the event of a dispute, the party invoking it must produce: the signed PDF, the audit trail (separate PDF certificate), the metadata (IP, timestamp, user agent). The judge assesses the reliability of the process. For the QES, it is up to the contesting party to prove the non-validity (legal presumption of reliability, decree 2017-1416).

Sign your first contract with Certyneo

Create a free account on certyneo.com/signup, upload your contract, add the signatories and send. You obtain in a few minutes a signed contract that is compliant, enforceable and archived. For an employment contract, consult our dedicated guide (/blog/signer-contrat-travail-electronième). To understand the legal value compared electronic signature vs handwritten, see our article (/blog/electronic-signature-vs-handwritten-legal-value).