Types of electronic signatures: QES, AES, and SES explained

An electronic signature is electronic data used by a signer to approve or agree to a document’s terms — a concept that enjoys widespread global acceptance. Under the EU’s eIDAS Regulation, eSignatures fall into three legally distinct tiers: simple (SES), advanced (AES), and qualified (QES). Each tier carries a different level of identity assurance and a different legal weight. The distinction matters because eIDAS Regulation (EU) No 910/2014 treats these tiers as a graduated scale rather than a single category: think of SES as a signed note, AES as showing a verified ID to a bank teller, and QES as a notarized signature witnessed by an accredited third party.

• The three tiers defined by the EU’s eIDAS Regulation are simple, advanced, and qualified electronic signatures.
• A simple electronic signature (SES) requires no identity verification; examples include a typed name or a click-to-agree checkbox.
• An advanced electronic signature (AES) uniquely identifies the signer, links to signature data under their sole control, and detects any subsequent changes to the electronic document.
• A qualified electronic signature (QES) meets all AES standards but requires a secure creation device and a certificate from an accredited provider. It is the only tier legally equivalent to a handwritten signature across the EU.
• Under eIDAS 2.0, the EU Digital Identity Wallet will allow member states to issue free QESs directly to individuals via smartphone by December 2026.
• The US ESIGN Act and UETA rely on a single-tier intent-and-consent standard rather than a multi-tiered system.
• SignNow provides SES by default, with AES and QES available through Qualified Trust Service Provider integrations as a Site License add-on.

What is an electronic signature?

An electronic signature is data in an electronic form used by a signer to approve or agree to the terms of a document. This simple concept enjoys widespread global acceptance.

Major international laws have established the legal validity of electronic signatures, ensuring their legal effect cannot be denied just because they are in electronic form.

Key regulations include:

• The United States: The Electronic Signatures in Global and National Commerce (ESIGN) Act and the Uniform Electronic Transactions Act (UETA) provide legal recognition for electronic signatures. You can learn more about ESIGN Act standards.
• The European Union: The eIDAS Regulation (Electronic Identification, Authentication and Trust Services) is the legal framework for electronic signatures across all EU member states. It clearly defines the three eSignature levels: simple electronic signature, advanced electronic signature, and qualified electronic signature.
• Canada: The Personal Information Protection and Electronic Documents Act (PIPEDA) recognizes the legal standing of electronic signatures that meet specific requirements.

While the terminology varies, most legal frameworks differentiate between basic electronic signatures (SES) and more secure “digital signatures,” which include AES and QES. Let’s explore each of these in greater detail.

What is a simple electronic signature (SES)?

A simple electronic signature (SES) is defined in eIDAS Article 3.10 as “any data in electronic form that is attached to or logically associated with other electronic data and used by the signer to sign it.” This definition covers the widest possible range of electronic signatures.

In practice, an SES can take several forms, including:

• A typed name at the bottom of an email
• A scanned image of a handwritten signature pasted into a document
• A click on an “I agree” checkbox
• A confirmation via an SMS code.

None of these methods verifies who the signer actually is beyond what the recipient already knows or trusts about them.

Why it matters

Under Article 25(1) of eIDAS, an SES cannot be denied legal effect or admissibility in court simply because it is electronic or falls short of qualified signature requirements. This means that even the most basic electronic signature carries genuine legal standing — it just doesn’t carry the same automatic equivalence to a handwritten signature that a qualified signature does.

SES fits low-risk, high-volume scenarios and routine business processes: internal HR forms, day-to-day vendor agreements, and business-to-consumer transactions where the parties already have an established relationship. Teams handling routine paperwork at this tier often rely on reusable document templates and bulk sending to move a high volume of low-risk agreements through quickly. SignNow’s default eSignature qualifies as an SES under eIDAS because the signature is created in electronic form, attached to the underlying document, and used by the signer to express intent to sign.

What is an advanced electronic signature (AES)?

An advanced electronic signature (AES) is uniquely linked to and identifies the signer, is created using data under their sole control, and ensures any subsequent changes to the data are detectable. These requirements are defined in eIDAS Article 3.11 and Article 26.

Most AES implementations rely on Public Key Infrastructure (PKI), where a Certificate Authority issues a digital certificate tied to the signer’s identity. This certificate cryptographically binds the signature to the document; if anyone alters the document afterward, the signature becomes invalid.

One important clarification: eIDAS does not grant AES a separate legal status from SES. Both tiers benefit from the same non-discrimination principle under Article 25(1). Where AES differs is in evidentiary strength: it provides a more robust, technically verifiable link between the signature and the identified signer, which becomes significant if a signature is later challenged.

Why it matters

In a dispute, the party relying on an AES has a materially stronger technical basis to prove who signed and that the document was not altered afterward than the party relying on an SES alone.

AES is well-suited to mid-risk transactions where higher security and identity assurance matters, but a fully qualified signature is not legally required — such as loan agreements, B2B contracts, HR offer letters, and cross-border commercial deals. According to SignNow’s compliance documentation, its signature process meets AES requirements: signer identification, sole control over signing data, and tamper detection. Every completed document also includes a detailed audit trail recording signer names, IP addresses, and timestamps, which supports the tamper-detection element of an AES.

What is a qualified electronic signature (QES)?

A qualified electronic signature (QES) is an advanced signature created using a secure creation device and backed by a certificate from an accredited Qualified Trust Service Provider. It is the only tier with automatic legal equivalence to a handwritten signature across the EU, a status granted directly by eIDAS Article 3.12 and Article 25(2).

Under Annex II of the regulation, a qualified signature creation device (QSCD) must meet several technical requirements:

• Keep signature creation data confidential
• Allow the data to be used only once
• Resist forgery with currently available technology
• Remain under the signer’s exclusive control

In plain terms, the device that generates a QES is built so that only the legitimate signer can trigger it, and only once per signature.

The certificate itself must come from a Qualified Trust Service Provider listed on the EU Trusted List and accredited by an EU member state. Before issuing the certificate, the QTSP has to verify the signer’s identity through a face-to-face check or an equivalent remote verification process, and it vouches for the authenticity of the resulting signature.

Why it matters

Because a QES is legally equivalent to a handwritten signature, the burden of proof shifts. A party challenging a QES generally has to prove it is invalid, rather than the relying party having to prove it is authentic.

QES applies to high-assurance transactions that require higher security: government filings, real estate and land registry transfers, notarial acts, and regulated financial or healthcare documents where the electronic signature law or a counterparty specifically requires it. Organizations handling this volume of documents typically also need 21 CFR Part 11 support or a signed HIPAA business associate agreement alongside QES, since these regulated-industry requirements often overlap.

How does a qualified electronic signature work?

Creating a QES involves a precise, high-assurance process that combines advanced technology with verified human identity.

The process relies on two key components that go beyond an Advanced Electronic Signature:

1. A Qualified Certificate: This is not just any digital certificate. It is a special certificate issued only by a Qualified Trust Service Provider (QTSP). A QTSP is an organization that has undergone a strict audit and is officially accredited by an EU national authority to provide these high-trust services.
2. A Qualified Signature Creation Device (QSCD): The signature itself must be generated using a QSCD. This is a secure, certified piece of hardware (like a USB token or smart card) or a secure remote (cloud-based) service that generates the signature data. This device ensures that the signer’s private key, used to create the signature, is secure and under their sole control.

When a signer uses a QES, the QTSP first performs an identity verification. Once verified, the QTSP issues the qualified certificate and uses the QSCD to apply a unique, encrypted signature to the document. This signature permanently links the signer’s verified identity to the document and seals it, making any future tampering immediately detectable.

Electronic signature types: SES vs. AES vs. QES compared

The three eIDAS signature tiers differ across five practical dimensions: how the signer’s identity is verified before signing, whether a digital certificate is required to authenticate the signature, what type of device is used to create the signature, who is responsible for issuing that certificate, and what legal weight the resulting signature carries in court or regulatory proceedings. Understanding how each tier measures up across these dimensions makes it easier to match the right signature type to the right use case.

Dimension	SES	AES	QES
Identity verification	None required	Signer uniquely identified via certificate	Face-to-face or equivalent remote ID verification
Certificate required	No	Digital certificate from a Certificate Authority	Qualified certificate from a QTSP
Signature creation device	Any (typed name, click, scanned image)	Signing data under the signer’s sole control	Qualified signature creation device (QSCD)
Issuing authority	None	Certificate Authority	Qualified Trust Service Provider on the EU Trusted List
Legal weight	Cannot be denied legal effect solely for being electronic (Art. 25.1)	Same non-discrimination protection, stronger evidentiary basis	Automatic legal equivalence to a handwritten signature EU-wide (Art. 25.2)
Typical use cases	Internal forms, low-value vendor agreements, routine B2C transactions	Loan agreements, B2B contracts, HR offer letters, cross-border commercial deals	Government filings, real estate transfers, notarial acts, regulated financial or healthcare documents

eIDAS itself does not mandate a specific tier for a specific document type. The choice depends on what an EU member state’s national law requires for that category of transaction, or on what the counterparties themselves agree to use, given the risk involved.

eIDAS 2.0 and the EU Digital Identity Wallet: what changes for QES

eIDAS 2.0, formally Regulation (EU) 2024/1183, entered into force on May 20, 2024. It requires every EU member state to offer citizens a European Digital Identity Wallet, or EUDI Wallet, by December 2026, which can issue qualified electronic signatures directly from a smartphone, free of charge for non-commercial use.

This marks a major practical shift. Under the original 2014 framework, obtaining a QES required physical hardware, such as a smart card or USB token tied to the signer’s identity. Under eIDAS 2.0, the EUDI Wallet itself acts as a software-based signature tool, linked to a government-issued digital identity that users control directly from their smartphones.

The free-of-charge provision applies only to individuals signing for personal, non-commercial purposes. Businesses and professionals will continue to obtain QES through commercial channels, typically via an eSignature platform integrated with an accredited QTSP.

Market analysts are already tracking this shift: qualified electronic signatures are the fastest-growing segment of the digital signature market from 2026 to 2033, a trend driven directly by the trust that comes with mandatory identity verification.

This shift signals that QES issuance is moving away from a niche, hardware-dependent process toward something closer to everyday smartphone use — at least for individual EU citizens. For businesses, the core legal requirements around QSCDs and QTSPs remain unchanged; what shifts is the infrastructure that member states must provide to their citizens.

How eIDAS signature levels compare to US law (ESIGN Act and UETA)

Unlike the EU’s three-tier eIDAS model, US federal and state laws treat electronic signatures as a single legal category. Under the ESIGN Act (2000) and the Uniform Electronic Transactions Act (UETA), adopted by nearly every state since 1999, electronic signatures hold the same legal weight as wet-ink signatures. Rather than relying on a tiered certificate hierarchy, US law simply requires intent to sign, consent to conduct business electronically, and record integrity.

This structural difference has practical consequences for cross-border agreements. A signature method that satisfies ESIGN and UETA domestically — such as a typed name or click-to-agree confirmation — is functionally closer to an SES than an AES or QES. If a US company signs an agreement with an EU counterparty, or under EU-governed law that requires an advanced or qualified electronic signature, satisfying US law alone will not be enough. Jurisdiction, not just the signing method, determines which framework applies and what tier is required. Companies operating across both regions typically need a platform with documented compliance across US and EU standards, rather than one built around a single jurisdiction’s rules.

How SignNow supports SES, AES, and QES

SignNow’s standard eSignature qualifies as a simple electronic signature by default, and the platform enables advanced and qualified signatures by integrating with accredited Qualified Trust Service Providers rather than issuing qualified certificates itself.

SignNow’s standard signing process meets the Article 3.10 definition of an SES: the signature is in electronic form, attached to the document, and used by the signer to indicate intent. According to SignNow’s eIDAS compliance documentation, the process also independently satisfies the AES requirements under Articles 3.11 and 26, covering unique signer identification, signing data under the signer’s sole control, and detection of subsequent tampering.

What about QES?

QES works differently. It is available as an add-on exclusively on SignNow’s Site License plan, and turning it on requires setup through SignNow Sales and Support: scoping the approved countries and trust service providers for a given account, configuring an integration with the eIDeasy trust-service platform, and enabling QES in the account’s Workflow settings. Once enabled, organizations can use several QES variants depending on their compliance and document requirements, including standard signNow eSignature routed through QES, PDF-QES, hash-based QES, and NOM-151 for Mexico.

Importantly, SignNow is not a Qualified Trust Service Provider (QTSP) itself. Instead, its QES qualified certificates are provided by connected, accredited QTSPs. This is standard practice for eSignature vendors, who integrate with licensed third parties rather than acting as their own certification authority.

For baseline compliance, all SignNow plans—including the entry-level Business tier—include ISO 27001 and SOC 2 Type II certification, GDPR compliance, and eIDAS SES. Advanced signer authentication starts at the Enterprise level, while QES, HIPAA compliance (with a signed BAA), and 21 CFR Part 11 support require a Site License. Teams can compare tiers on SignNow’s pricing page, where QES availability marks the main distinction between Enterprise and Site License plans.

“We can recommend SignNow not only because of compliance, but also because it is easy in use for us and for all the applicants.” — Lucija Hrvat, Course Coordinator at Istituto Italiano di Fotografia

How do I create a qualified electronic signature in SignNow?

SignNow’s platform makes sending and signing with QES simple by handling all the technical compliance requirements behind the scenes. Please note that QES is only available on the Site License plan, and integrates with eIDeasy for identity verification and qualified certificates. Enabling specific authentication methods may require additional invoicing, depending on which options your team asks Support to activate. Contact sales to learn more about volume-based discounts and to unlock access.

Requesting a QES (recipient):

1. Enable QES
   First, an account administrator contacts the SignNow sales team to activate QES. The activation process takes no more than 1-2 days. Once active, the admin can enable QES mode in the account settings.
   
   
   
2. Prepare a document
   Set up your document invite as you normally would, adding the signer and any required fields. A key requirement for QES is that you can only have one signer per signing step.
   
3. Select QES signature type
   When configuring the recipient’s settings, click to open Authentication and Settings. Change the signature type to Qualified Electronic Signature (QES).
   
   
   
4. Confirm settings: You will see a notification that QES settings will apply to all signers. The “ID Verification Type” will be automatically set to ID Verification via eID Easy, which manages the connection to the various QTSPs.
   
5. Send Invite: Click Apply and send your document. The recipient will now have to complete the QES process to sign.

Pro tip: Merge multiple documents before sending. If you don’t need sequential signing, you’ll only pay for one document certificate this way.

Signing with QES (recipient):

1. Open an eSignature invite
   You will receive an email invitation to sign. Open the document and fill out all the required fields.
   
2. Start verification
   After completing the document, a pop-up appears prompting you to verify your identity to sign. Click Get Started.
   
   
   
3. Choose your provider
   Select your country. Based on your selection, a list of available QTSPs (like BankID, Evrotrust, sign-me, etc.) will appear. Select the provider you use or wish to use. SignNow works with over 50 QTSPs.
   
   
   
4. Complete verification
   Follow the on-screen instructions for your chosen provider. This process is different for each QTSP but may require you to use a mobile app, enter a personal identity code, or use a government-issued ID.
   
5. Finish signing
   Once the QTSP has successfully verified your identity, your Qualified Electronic Signature applies to the document. The document is now signed, and you will see a confirmation page where you can download the certified document.
   
   

How to choose the right signature tier for your document

Choosing between SES, AES, and QES depends on your transaction’s legal risk, the jurisdiction, and any requirements from local laws or your counterparty.

1. Check for mandates: Verify if local laws or your partner require a specific tier. For example, some EU member states mandate a QES for real estate transfers or notarial acts.
2. Use SES for low-risk tasks: For routine business documents where speed is more important than certificate-backed proof, an SES is usually sufficient.
3. Use AES for moderate risk: For contracts with financial or legal exposure that do not strictly require a QES, an AES provides a stronger identity link without the overhead of a qualified certificate.
4. Use QES for maximum protection: For documents that require automatic, EU-wide legal equivalence to a handwritten signature, or those facing a high risk of dispute, QES is the standard.

A few concrete scenarios illustrate how this plays out by industry. In legal practice, routine NDAs and other legal agreements often use SES, while cross-border settlements with high enforcement risks require AES. In real estate, property transfers in several EU states legally mandate QES. In human resources, offer letters and onboarding paperwork use SES or AES, balancing speed with identity assurance. In finance, loan and credit agreements commonly use AES to establish a verifiable identity link without triggering statutory QES requirements.

Some EU member states also require additional legal formalities beyond electronic signatures for certain transactions. This includes real estate transfers, agreements involving courts or public authorities, personal guarantees, and family or inheritance law. SignNow’s legality documentation for the European Union outlines these categories in more detail for readers dealing with EU-governed transactions. Organizations in real estate, financial services, and healthcare are the most likely to encounter these carve-outs in practice, since those industries carry the highest concentration of member-state-specific signature requirements.

Final thoughts

The eIDAS Regulation establishes three electronic signature tiers, each offering a different level of security and legal weight: simple (SES), advanced (AES), and qualified (QES). SES covers everyday signing and requires no identity verification. AES uniquely identifies the signer and detects subsequent document changes. QES requires a government-accredited trust layer, making it the only tier legally equivalent to a handwritten signature across the EU.

Meanwhile, US law—governed by the ESIGN Act and UETA—treats electronic signatures as a single, intent-based category. This difference is critical for cross-border agreements. As eIDAS 2.0 requires EU member states to offer free, smartphone-based QES by December 2026, knowing which tier your documents require is more important than ever.

SignNow covers all three tiers without the need for multiple vendors. Its standard eSignature qualifies as an SES under eIDAS Article 3.10 and meets AES requirements under Articles 3.11 and 26—including unique signer identification and tamper detection via a detailed audit trail. For the highest level of assurance, QES is available as a Site License add-on through accredited Qualified Trust Service Provider integrations. From routine HR forms to cross-border contracts, SignNow scales to match your legal compliance needs.

Ready to put the right signature tier behind your documents? Start your free SignNow trial and explore top eSignature capabilities in one platform.

Key terms

• Advanced electronic signature (AES): An electronic signature uniquely linked to the signer, created using signing data under the signer’s sole control, and capable of detecting subsequent changes to the signed data, as defined in eIDAS Article 3.11.
• eIDAS Regulation: Regulation (EU) No 910/2014, the EU law governing electronic identification and trust services, including the legal framework for SES, AES, and QES.
• EU Digital Identity Wallet (EUDI Wallet): A smartphone-based digital identity tool that EU member states must offer citizens under eIDAS 2.0, capable of issuing qualified electronic signatures.
• ESIGN Act: The Electronic Signatures in Global and National Commerce Act, a US federal law passed in 2000 that grants electronic signatures the same legal force as paper signatures.
• Qualified electronic signature (QES): An advanced electronic signature created with a qualified signature creation device and backed by a qualified certificate from a Qualified Trust Service Provider, carrying automatic legal equivalence to a handwritten signature across the EU.
• Qualified Signature Creation Device (QSCD): Hardware or software meeting the technical requirements of eIDAS Annex II for generating a qualified electronic signature under the signer’s exclusive control.
• Qualified Trust Service Provider (QTSP):An entity accredited by an EU member state and listed on the EU Trusted List that verifies signer identity and issues qualified certificates for QES.
• UETA: The Uniform Electronic Transactions Act, a US model law adopted by nearly every state that grants electronic signatures and records the same legal status as their paper equivalents.

FAQs

1. What are the 3 types of electronic signatures?
Under eIDAS Regulation (EU) No 910/2014, the three types of electronic signatures are simple (SES), advanced (AES), and qualified (QES). They differ in the level of identity verification required and the legal weight they carry. QES is the only tier that automatically holds the same legal status as a handwritten signature across the EU.

2. What is the difference between an advanced and a qualified electronic signature?
An advanced electronic signature (AES) uniquely identifies the signer and relies on signing data under their sole control, typically via a digital certificate from a Certificate Authority. A qualified electronic signature (QES) meets all the same requirements but also requires a qualified signature creation device and a qualified certificate issued by an accredited Qualified Trust Service Provider (QTSP). This additional layer is what gives QES automatic legal equivalence to a handwritten signature.

3. Is a simple electronic signature legally binding?
Yes. Under Article 25(1) of the eIDAS Regulation, an electronic signature cannot be denied legal effect or admissibility as evidence solely because it is electronic or because it does not meet the requirements of a qualified signature. It does not, however, carry the automatic legal equivalence to a handwritten signature that a qualified electronic signature carries.

4. What is a Qualified Trust Service Provider (QTSP)?
A Qualified Trust Service Provider is an organization accredited by an EU member state and listed on the EU Trusted List that is authorized to issue qualified certificates for electronic signatures. Before issuing a certificate, a QTSP must verify the signer’s identity through a face-to-face check or an equivalent remote verification process.

5. Does the US recognize eIDAS signature levels?
No. US federal and state law, through the ESIGN Act and the Uniform Electronic Transactions Act, treats electronic signatures as a single legal category based on intent, consent, and record integrity, rather than the three-tier structure eIDAS defines. A signature valid under US law is not automatically equivalent to an EU advanced or qualified electronic signature.

6. What is eIDAS 2.0, and how does it affect qualified electronic signatures?
eIDAS 2.0, or Regulation (EU) 2024/1183, entered into force in May 2024 and establishes the European Digital Identity Wallet framework. It requires EU member states to offer citizens a smartphone-based digital identity wallet by December 2026 that can issue qualified electronic signatures free of charge for non-commercial use, shifting QES issuance away from physical hardware devices like smart cards or USB tokens.

Sources

• eIDAS Regulation (EU) No 910/2014
• Regulation (EU) 2024/1183 (eIDAS 2.0) / EU Digital Identity framework, European Commission
• Digital Signature Market Size & Share Report, 2026-2033, Grand View Research
• Electronic Signatures in Global and National Commerce Act, Public Law 106-229, govinfo.gov
• Uniform Electronic Transactions Act overview, Uniform Law Commission via Wikipedia
• Personal Information Protection and Electronic Documents Act (PIPEDA)
• Legality of eSignatures in European Union, SignNow
• SignNow industry-leading compliance
• SignNow solutions for real estate professionals