What is an Electronic Signature? 2026 Guide

Definition and context

An electronic signature is a technical process that allows a person to express their consent to a digital document with the same value as a handwritten signature on paper. It is not simply 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, qualified. Each level corresponds to different requirements regarding the identification of the signatory and the strength of the evidence.

Why electronic signature has become essential

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

A few figures often cited in the profession:

• a paper contract takes between 2 and 5 days to return signed on average;

• the same operation with 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 figures, electronic signature provides superior traceability: every step is time-stamped, every action by the signatory is recorded, the IP address is captured. Paper, on the other hand, leaves only a scribble.

How does an electronic signature work?

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

• The sender uploads a document (most often a PDF) to a signature platform.

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

• Each signatory receives a secure link by email. 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 time-stamp, and integrates everything into the final PDF.

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

For more details on 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 stakes of the document, not systematically use the strongest (more demanding = more friction cost for the signatory).

• Simple (SES): a simple click or checkbox is enough. Suitable for documents with low stakes: 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 accredited Qualified Trust Service Provider (QTSP). Legally equivalent to a handwritten signature throughout the EU. Reserved for deeds or highly formal acts.

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

Documents that can be electronically signed

In practice, virtually all contractual and commercial documents can now be electronically signed:

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

• quotations, purchase orders, pro forma invoices

• confidentiality agreements (NDAs)

• sales mandates, management mandates

• residential and commercial leases

• inter-company agreements, protocols of agreement

• amendments, powers of attorney, certificates

Some documents remain excluded or subject to conditions (notarial deeds, civil status documents, certain court proceedings): check the framework applicable to 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, eIDAS and GDPR compliant by design. It covers simple (SES) and advanced (AES) levels with double-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 an audit footer, a time-stamped journal kept for 10 years and reusable evidence in case of dispute.

Discover the Certyneo electronic signature solution

FAQ

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

Yes, provided that the signature level is appropriate to the document and that the identification of the signatory and the integrity of the document 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.

Which level of signature should you choose?

For the majority of everyday cases (quotations, purchase orders, internal agreements), a simple signature is sufficient. For an employment contract, lease or mandate, prefer an 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 touch screen.

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 gimmick: it is a productivity tool that divides the signing 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.