QES vs AES: a product decision, not a legal slide
Every SaaS team that wants digital contracts hits QES vs AES. eIDAS defines three levels: simple (SES), advanced (AES) and qualified (QES). Qualified often replaces statutory written form. AES carries strong evidential weight without always providing that form replacement. SES is the fast, attributable click — useful, not universal.
Help answers this briefly; this URL is the crawlable piece for teams locking the level into the roadmap.
When does SaaS need QES?
Whenever law or contract requires written form, or the counterparty (bank, authority, regulated group) mandates QES. Qualification runs through a Qualified Trust Service Provider. Sign2x is the engine, not the QTSP: identity and certificate come via partners such as Sign8. The flow stays in your software without you becoming a trust service provider.
Is AES enough in B2B?
Often yes: offer acceptance, approvals, NDAs, operational contracts without statutory written form. AES must be uniquely linked to the signatory and detect later changes. That is what legal means by “binding, but not QES”. SES fits internal confirmations and low-risk flows — not as the default for customer contracts.
eIDAS levels in one API
You need a level per envelope, not three products. Sign2x supports SES, AES, QES and electronic seals in the same API, hosted in Germany on STACKIT and Telekom. Dispatch via email, link or SMS. Legal chooses the level; the stack must not block it. More in the Help Center and Developer Hub.
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Frequently asked questions
When do I need QES?
When written form is required by law or contract, or the counterparty demands QES. Qualification runs through a QTSP (with Sign2x via partners such as Sign8), not through Sign2x itself.
Is AES enough in B2B?
Often yes, if written form does not apply. AES must be linked to the signatory and protect integrity. For many operational B2B contracts that is the right level.
What is SES?
The simple electronic signature: an attributable electronic close without AES/QES technical bars. Fine for low-risk and internal flows, not the default for customer contracts.
