Simple vs Advanced vs Qualified Electronic Signature: Real Differences

Signing a document electronically may seem simple, but behind the scenes there are three levels of signature recognized by the eIDAS Regulation: simple, advanced, and qualified. Each offers a different degree of security, identification, and evidentiary strength.

Understanding their differences is key to choosing the right one for your legal and operational context.

What the eIDAS Regulation says

The EU Regulation 910/2014 (eIDAS) defines the legal framework governing electronic signatures in Europe. It recognizes three levels:

1. Simple Electronic Signature (SES)
   Covers any method that shows the intention to sign — for example, a click, an email reply, or a handwritten trace on a touchscreen.

2. Advanced Electronic Signature (AES)
   Enables unique identification of the signer, linking their identity to the document through control data, timestamps, or cryptographic keys.

3. Qualified Electronic Signature (QES)
   Is based on a qualified certificate issued by a trusted service provider and has the same legal value as a handwritten signature.

Comparison table

Simple signature: agile and sufficient in most cases

The simple electronic signature is the most common and versatile. It only requires the system to demonstrate who signed, what was signed, and when.

It is ideal for validating consents, low-value contracts, or internal agreements, providing agility and savings. At eEvidence, eEvidSign combines this with registered email and timestamping, adding full legal traceability without technical complexity.

Advantages:

• Fast, no certificates or software required.
• Legally valid under Article 25 of the eIDAS Regulation.
• Perfect for large-scale or automated processes.

Advanced signature: more robust and with stronger identification

The advanced electronic signature (AES) creates a technical link between the signer and the document. It often includes elements such as:

• Identification via email, mobile number, or ID document.
• Technical evidence (hashes, logs, timestamps).
• Exclusive control by the signer over their signing data.

Its higher assurance level makes it ideal for commercial contracts, HR processes, or agreements with legal implications.

At eEvidence, the advanced eEvidSign maintains a smooth user experience, with no need for complex certificates.

Advantages:

• High traceability and authenticity.
• Strong evidentiary value in court.
• Compatible with remote signing and automation.

Qualified signature: maximum security, minimum usability

The qualified electronic signature (QES) is the highest level of assurance under eIDAS — but also the least flexible. It requires the signer to use a qualified certificate issued by a qualified trust service provider (QTSP) and a secure signature creation device (such as a token, smartcard, or national ID).

While it provides the strongest legal proof, its technical complexity limits its practical use to institutional or high-assurance contexts.

Disadvantages:

• Requires prior or in-person identification.
• Often incompatible with mobile devices or modern browsers.
• Costs of issuing, renewing, and maintaining certificates.
• Low scalability for large digital workflows.

For these reasons, most companies avoid using it in everyday operations, preferring the advanced signature, which offers nearly the same legal value with far less friction.

When to use each type of signature

Frequently Asked Questions (FAQ)

Are all electronic signatures legally valid?

Yes. The eIDAS Regulation states that no electronic signature can be denied legal effect solely because it is electronic, although the level of assurance determines its evidentiary weight.

Is a qualified signature always necessary?

No. In most private or business relationships, an advanced or even simple signature is sufficient, as long as there is traceability and technical evidence.

How do I know which type of signature I need?

It depends on the legal risk of the document. If maximum security is required (e.g., notarial contracts), use a qualified signature.
For most business agreements, an advanced or simple signature is enough.

Can I combine a signature with registered email?

Yes. Integrating electronic signature and registered email is the most reliable way to ensure authenticity, content, and delivery.

Conclusion

The differences between simple, advanced, and qualified signatures are not about validity, but about level of assurance and usability.

While the qualified signature is reserved for high-assurance legal contexts, the simple and advanced signatures are what truly drive digital transformation — fast, legal, and secure.

With solutions like eEvidSign by eEvidence, businesses can sign documents with full traceability and zero friction, achieving the perfect balance between security, efficiency, and legal validity.