What Is an Electronic Signature? 2026 Guide

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 scribble pasted onto a PDF: behind the signature lies a cryptographic mechanism that links the signer 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 signer identification and the strength of proof.

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 expensive in terms of time and logistics.

A few commonly cited figures in the profession:

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

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

• the full 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 timestamped, each action by the signer is recorded, the IP address is captured. Paper only leaves a scribble.

How Does an Electronic Signature Work?

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

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

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

• Each signer 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 signer's identity and a timestamp, and integrates everything into the final PDF.

• The signed PDF now carries an audit trail: timestamped 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 friction for the signer).

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

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

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

For the full 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, internship)

• quotations, purchase orders, pro-forma invoices

• confidentiality agreements (NDA)

• sale mandates, management mandates

• residential and commercial leases

• inter-company agreements, protocols

• amendments, powers of attorney, attestations

Certain acts remain excluded or subject to conditions (notarial acts, vital records, certain judicial proceedings): verify the applicable framework for your document before launching a signature with strong evidential 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 two-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 timestamped log kept for 10 years, and reusable proof 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 signer's identification and document integrity are provable. In Europe, the eIDAS regulation establishes a non-discrimination principle: a signature cannot be refused as evidence solely on the grounds that it is electronic.

Which signature level should I choose?

For the majority of everyday cases (quotations, purchase orders, internal agreements), a simple signature is sufficient. For an employment contract, a lease, or a mandate, opt for 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 I sign from a smartphone?

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

What happens in case of dispute?

The platform provides, upon request, the complete audit trail: timestamp, IP address, authentication, cryptographic fingerprint. This reusable proof 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 familiarize yourself, then gradually extend to your entire processes.

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