Simple, Advanced, and Qualified Electronic Signature: What’s the Difference?

An electronic signature — often called an e-signature — is a way to sign documents digitally, without the need to print, scan, or sign by hand. It replaces the traditional “wet ink” signature in a fast, secure, and legally recognised way.

According to the eIDAS Regulation (the EU legal framework for electronic identification and trust services), an electronic signature is:

"Data in electronic form which is attached to or logically associated with other data and which is used by the signatory to sign."

In simpler terms, it’s a digital method of expressing consent or approval, using tools that can range from a typed name to a fully secured cryptographic signature.

Examples of electronic signatures include:

• Typing your name at the end of an email
• Clicking “I agree” to accept terms of a contract
• Drawing your signature using a mouse or touchscreen
• Using a verified signature process on platforms like Yousign

Each of these qualifies as an electronic signature — but they don’t all carry the same legal weight. That’s why understanding the different types of electronic signatures is essential.

Electronic signatures are legally recognised in the EU and UK under eIDAS. However, the strength of the signature — and how easily it holds up in court — depends on the type used:

• Simple Electronic Signature (SES) – Basic proof of intent
• Advanced Electronic Signature (AES) – Secure and identity-linked
• Qualified Electronic Signature (QES) – Highest level, legally equivalent to handwritten

The stronger the signature, the stronger your legal protection — especially in case of disputes.

A Simple Electronic Signature (SES) is the most basic level of electronic signature defined under the eIDAS Regulation. It’s widely used in everyday business processes where the risk is low and the need for identity verification is minimal.

A Simple Electronic Signature is:

“Any electronic data that is logically associated with other data and used by the signatory to sign.”

In practice, this could mean:

• Typing your name at the end of an email
• Clicking a checkbox to approve terms
• Inserting an image of your handwritten signature into a PDF
• Using a basic online signature tool without identity verification

• Fast and easy to use
• No complex identification process required
• Common for everyday business transactions
• Shows intent to sign, but offers limited legal evidence if challenged

Use a Simple Electronic Signature when:

• The document is low-risk
• The signer is internal (e.g. HR forms, internal approvals)
• You don’t need to verify identity beyond a reasonable doubt

Examples:

• NDAs
• Internal policy acknowledgements
• Employee onboarding paperwork
• Non-sensitive sales agreements

While SES is legally valid, it does not provide strong legal proof of who signed the document. In the event of a legal dispute, it may be difficult to prove authenticity or intent without additional supporting evidence.

For higher-risk or external documents, consider upgrading to Advanced or Qualified Electronic Signatures — both of which Yousign supports.

An Advanced Electronic Signature (AES) is a higher-security form of e-signature, offering stronger legal protection and more robust identity verification than a Simple Electronic Signature (SES).

It’s ideal for situations where you need to prove who signed, ensure the document hasn’t been altered, and minimise legal risk.

An Advanced Electronic Signature must:

• Be uniquely linked to the signer
• Be capable of identifying the signer
• Be created under the sole control of the signer
• Be linked to the signed data in a way that any modification is detectable

Yousign’s platform is fully compliant with these requirements.

• Strong identity verification (e.g. email, SMS OTP, ID document)
• Tamper-evident signing process
• Includes a time-stamped audit trail
• Stored and managed by a Trusted Service Provider (TSP) like Yousign

Advanced Electronic Signatures are ideal for:

• Commercial contracts
• Supplier agreements
• Client onboarding
• Purchase orders and invoices
• Employment contracts
• Freelance or service agreements

Any document that could be challenged in court or involves external parties benefits from an AES.

In the EU and UK, AES carries strong evidential value. If a dispute arises, the AES process includes:

• Proof of signer identity
• Confirmation of document integrity
• A verifiable audit trail

With Yousign, every advanced signature is backed by secure identity checks, real-time validation, and encrypted storage — ensuring compliance and peace of mind.

A Qualified Electronic Signature (QES) is the most secure and legally robust form of electronic signature under the eIDAS Regulation. It is the only type of e-signature that is legally equivalent to a handwritten signature across the EU and UK.

This level of signature is used when maximum legal assurance is required — particularly in regulated industries or official procedures.

A Qualified Electronic Signature must meet all the criteria of an Advanced Electronic Signature, and additionally:

• Be created by a Qualified Signature Creation Device (QSCD)
• Be issued by a Qualified Trust Service Provider (QTSP), such as Yousign

This combination ensures maximum identity verification, document integrity, and compliance with EU law.

• Full legal equivalence to handwritten signatures
• Requires verified identity (in-person or remote ID check)
• Uses a certified signature device (e.g., smartcard, token, secure cloud)
• Delivered exclusively by QTSPs (Qualified Trust Service Providers)
• Includes a qualified certificate linked to the signer

Qualified Electronic Signatures are best for:

• Government forms and filings
• Public procurement procedures
• Court documents
• Real estate transactions
• Cross-border agreements in regulated sectors

In some jurisdictions or industries, QES is legally required for certain document types.

A QES provides:

• Presumption of legal validity across the EU
• Maximum protection in case of legal disputes
• Burden of proof is reversed: the signature is considered valid unless proven otherwise

If legal certainty is critical, QES is the safest option — and Yousign can provide it when your use case demands this level of assurance.

Choosing between a Simple, Advanced, or Qualified Electronic Signature depends on three key factors:
the sensitivity of the document, the legal risk, and the identity verification required.

Here’s how to make the right decision for your needs:

• The risk is low
• The signer is someone you trust internally
• You’re dealing with basic approvals or informal agreements

Examples:

• Internal HR forms
• Expense approvals
• NDAs (low sensitivity)

• You need strong proof of identity
• The contract involves external parties
• The document holds financial or legal value

Examples:

• Client or vendor contracts
• Employment agreements
• Sales or purchase orders
• Project-based freelance contracts

AES is the go-to standard for most business workflows — and it’s fully supported by Yousign with identity verification and audit trails built-in.

• The law requires the highest level of authentication
• You're operating in a regulated industry
• You want to guarantee maximum legal protection

Examples:

• Real estate transactions
• Government-related filings
• Large-scale public tenders
• Legal proceedings

Understanding the difference between SES, AES, and QES is essential for making the right choice for your business or personal documents.

To recap:

• SES is great for low-risk internal tasks
• AES is the standard for legally sensitive business documents
• QES is ideal for highly regulated or legally binding documents

With Yousign, you don’t have to choose blindly. Our platform supports all three levels of electronic signature, allowing you to stay compliant, secure, and efficient — no matter the use case.

Whether you're onboarding a new client or signing a multi-party agreement, Yousign gives you the legal confidence to sign smarter.