What is an Electronic Signature? Guide 2026

Definition and context

An electronic signature is a technical process that allows a person to manifest their consent on a digital document, with the same value as a handwritten signature on paper. It is not limited to an image of a paraph pasted onto a PDF: behind the signature lies a cryptographic mechanism that links the signatory to the document and guarantees its integrity.

The reference framework in Europe is the eIDAS regulation (No. 910/2014), which defines three levels: simple, advanced, and qualified. Each level corresponds to different requirements regarding the signatory's identification and the strength of the evidence.

Why electronic signature has become essential

Companies today process dozens of contractual documents per week: employment contracts, quotations, purchase orders, mandates, leases, NDAs… Circulating these documents in paper form is costly in terms of time and logistics.

A few figures often cited in the profession:

• a paper contract takes between 2 to 5 days to come back signed on average;

• the same operation in electronic signature takes a few minutes to a few hours;

• the complete cost of a paper cycle (printing, postage, archiving, follow-up) is around €15 to €35 per document.

Beyond the numbers, electronic signature provides superior traceability: each step is time-stamped, each action of the signatory is recorded, the IP address is captured. Paper, on the other hand, only leaves a scribble.

How does an electronic signature work?

The process always follows the same logic, regardless of the provider:

• The sender deposits a document (most often a PDF) on a signature platform.

• They add the recipients (signatories), place the signature fields and define the order.

• Each signatory receives a secure email link. They open the document, authentication is verified (OTP via SMS for the advanced level for example), they click to sign.

• The platform calculates a cryptographic fingerprint of the document, associates it with the signatory's identity and a timestamp, and integrates everything into the final PDF.

• The signed PDF now includes an audit trail: time-stamped log of all actions, IP address, user-agent, OTP confirmation.

To learn more about the mechanics, see how an electronic signature works.

The three eIDAS levels

The European regulation distinguishes three levels of electronic signature. Best practice is to choose the level appropriate to the document's stakes, not to systematically take the strongest (more demanding = more costly in friction for the signatory).

• Simple (SES): a simple click or checkbox is enough. Suitable for low-stakes documents: quotations, purchase orders, internal agreements.

• Advanced (AES): identification of the signatory by a second factor (OTP SMS + email typically). Unique link between the signatory and the document. Suitable for employment contracts, leases, mandates.

• Qualified (QES): qualified certificate issued by an approved Qualified Trust Service Provider (QTSP). Equivalent in law to a handwritten signature throughout the EU. Reserved for authentic or highly formal acts.

For the complete distinction with examples, see simple, advanced, qualified: what are the differences.

Documents that can be signed electronically

In practice, almost all contractual and commercial documents are now signed electronically:

• employment contracts (permanent, fixed-term, apprenticeship)

• quotations, purchase orders, pro-forma invoices

• confidentiality agreements (NDA)

• sales mandates, management mandates

• residential and commercial leases

• inter-company agreements, protocols of agreement

• amendments, powers of attorney, certificates

Certain acts remain excluded or subject to conditions (notarial deeds, civil status records, certain judicial procedures): verify the applicable framework for your document before launching a signature with strong probative value.

How Certyneo helps you

Certyneo is a European electronic signature platform, hosted in the EU, compliant with eIDAS and GDPR by design. It covers simple (SES) and advanced (AES) levels with dual-factor authentication (email + OTP SMS via Twilio Verify), and interfaces with qualified providers for qualified signatures (QES) when the use case requires it.

Each envelope sent via Certyneo automatically generates a signed PDF with audit footer, a time-stamped log kept for 10 years and reusable evidence in case of dispute.

Discover the Certyneo electronic signature solution

FAQ

Does electronic signature have the same value as a handwritten signature?

Yes, provided that the signature level is appropriate to the document and that the signatory's identification as well as the document's integrity are provable. In Europe, the eIDAS regulation establishes a principle of non-discrimination: a signature cannot be rejected as evidence solely on the grounds that it is electronic.

What level of signature should I choose?

For the majority of everyday cases (quotations, purchase orders, internal agreements), simple signature is sufficient. For an employment contract, a lease or a mandate, favour advanced signature. For an act with very high legal value, explore qualified signature.

Is electronic signature free?

Some platforms offer a free plan for a few signatures per month. Beyond that, the tool becomes paid. See the free/paid comparison.

Can you sign from a smartphone?

Yes, all modern platforms allow you to sign from a smartphone or tablet. The signatory clicks on the link received by email and can sign directly on the touchscreen.

What happens in case of dispute?

The platform provides on request the complete audit trail: time-stamping, IP address, authentication, cryptographic fingerprint. This reusable evidence is accepted by French and European courts as long as it complies with eIDAS.

Conclusion

Electronic signature is no longer a gadget: it is a productivity tool that divides the signature cycle by 10, reduces administrative costs and provides superior traceability compared to paper. Start with low-stakes documents to familiarise yourself, then gradually extend to all your processes.

Try Certyneo to send, sign and track your documents online simply, quickly and securely.