Glossary
QES vs AES vs SES: the Three eIDAS Signature Levels
EU law recognises three levels of electronic signature under the eIDAS Regulation: simple, advanced and qualified. Each has a different legal weight and a different bar to clear. This guide explains what separates them, which documents typically need the top tier, and why an advanced signature with a seal and an evidence page is enough for most everyday client onboarding.
- Simple, advanced and qualified: three legal tiers under eIDAS
- Only qualified reaches the same legal weight as a handwritten signature
- Advanced, sealed and evidenced is enough for most onboarding documents
What are the three eIDAS signature levels
The eIDAS Regulation, (EU) 910/2014, sets out three tiers in Article 3. A simple electronic signature is any data in electronic form attached to other data and used by the signatory to sign, which can be as basic as a typed name or a ticked box. An advanced electronic signature must be uniquely linked to the signatory, capable of identifying them, created using data the signatory can use under their sole control, and linked to the signed data so any later change is detectable. A qualified electronic signature meets the advanced requirements and is additionally created by a qualified signature creation device, backed by a qualified certificate issued by a certified trust service provider.
What legal effect does each level actually have
Article 25 of the eIDAS Regulation sets the baseline: an electronic signature cannot be denied legal effect or refused as evidence in court solely because it is electronic or does not meet the qualified requirements. That protects simple and advanced signatures alike; a judge cannot throw one out on format grounds alone. What changes at the top tier is presumption, not admissibility. A qualified electronic signature is given the equivalent legal effect of a handwritten signature by law, and one issued in any member state must be recognised in every other member state. An advanced signature can still be shown valid, it is just proven rather than presumed.
Which documents in the EU typically require a qualified signature
National law, not eIDAS itself, decides which documents need the top tier, and the list varies by country. The recurring pattern across member states is notarial acts, certain real-estate transfers, company formation documents filed with a public registry, and a handful of other formal deeds where the law has historically required a notary or an in-person, witnessed process. Outside those specific cases, most private-law documents, contracts, engagement letters, consent forms, standard agreements between a business and its client, do not require a qualified signature. Check with your professional body or a local lawyer before assuming a particular document sits in the qualified-only category, since the exact list differs from one EU country to the next.
Why is an advanced signature enough for most client onboarding
An engagement letter, a service agreement, a consent form or a data-processing addendum are private-law documents between a business and a client, not the notarial or registry filings that typically require a qualified signature. For those, an advanced electronic signature already carries full legal effect and admissibility under Article 25, and pairing it with a PAdES seal and an evidence page, recording consent time, device and identity method, gives you something concrete to show if a client ever disputes what they signed. Reaching for a qualified signature on every document adds a certified signing device and a qualified certificate for documents that do not need either.
Does Braigest provide a qualified signature
No. Braigest provides an advanced electronic signature with a native PAdES seal, not a qualified electronic signature. That is a deliberate scope: it covers the private-law documents most client onboarding involves, without adding a qualified signing device or a qualified certificate to the flow. If a specific document in your process falls into the small category that national law reserves for a qualified signature, route that one document through a qualified signing process separately and keep the rest of the onboarding, forms, identity checks, other documents, in the same advanced-signature flow.
Why it matters when onboarding a client
Knowing where your documents sit on this scale stops two common mistakes: paying for a qualified signature product you do not need, or assuming an electronic signature will not hold up and reverting to print and post. Most onboarding documents, engagement letters, service agreements, consent and data-processing forms, only need to be advanced, sealed and evidenced. Reserve the qualified tier for the specific filings your national law actually names, and check that list with your professional body rather than guessing.
In Braigest
Advanced, sealed and evidenced, on every plan
Braigest signs with a native advanced electronic signature and a PAdES seal, built into the flow at no extra seat cost, starting on Solo at €29 a month.
Frequently asked questions
What is the difference between AES and QES?
An advanced electronic signature (AES) is uniquely linked to the signatory and tamper-evident. A qualified electronic signature (QES) meets those same requirements plus a certified signing device and a qualified certificate, and carries the same legal weight as a handwritten signature.
Is a simple electronic signature, like a typed name, legally valid?
It can be. Under Article 25 of the eIDAS Regulation, no electronic signature can be denied legal effect solely for being electronic, but a simple signature is harder to prove if it is ever disputed, since it carries no built-in identity or tamper check.
Which signature level does an engagement letter need?
In most EU countries, an engagement letter is a private-law document that only needs an advanced electronic signature, not a qualified one. Check with your professional body if your document type is unusual.
Does Braigest support qualified electronic signatures?
No, Braigest provides advanced electronic signatures with a native PAdES seal. For the specific documents your national law reserves for a qualified signature, route those through a qualified signing process separately.
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