eIDAS SES Signature: Why Not QES for Your Contracts?

Electronic signatures in Europe are regulated by the eIDAS Directive (EU Regulation 910/2014). And contrary to popular belief, there's no single "best" electronic signature.

There are three levels, each with its legal validity, cost, and use case. At Scell.io, we support the SES level — the best fit for 90% of companies. Here's why.

The three eIDAS levels

SES (Simple Electronic Signature)

• ✅ Unverified identity (email and OTP suffice)
• ✅ No external trust provider required
• ✅ Cost: free or near-free (a few cents per signature)
• ✅ Time: instant (~2 seconds)
• ✅ Easy integration (simple API)

Legal equivalent: handwritten signature if both parties accept the terms.

AES (Advanced Electronic Signature)

• ✅ Verified identity + audit trail
• ✅ Trust provider for validation
• ⚠ Cost: €5–20 per signature
• ⚠ Time: 5–30 minutes (manual review possible)
• ⚠ Medium complexity

Legal equivalent: stronger proof than SES, but not universally accepted.

QES (Qualified Electronic Signature)

• ✅✅ Officially verified identity (notary, national ID)
• ✅✅ Full audit trail + blockchain optional
• ✅✅ Valid in 100% of legal procedures (France, EU, sensitive contracts)
• ❌ Cost: €50–500 per signature
• ❌ Time: 1–7 days
• ❌ High complexity (requires certified trust provider)

Legal equivalent: notarized paraph in terms of evidence. Recognized everywhere.

Decision matrix: which level for what?

Use case	SES	AES	QES
B2B commercial contracts	✅✅	⚠	❌ overkill
Signable quotes	✅✅	⚠	❌
Terms and conditions	✅✅	⚠	❌
NDAs / confidentiality	✅	✅✅	⚠
Employment agreements	✅	✅✅	⚠
Notarial deeds	❌	❌	✅✅
Real estate/inheritance	❌	❌	✅✅
Medical sensitive	⚠	✅✅	✅✅
Public contracts (bids)	⚠	✅✅	✅

Why SES for most cases?

Legal argument

French law recognizes simple electronic signatures if the overall context suggests consent. For a B2B quote, a clause in your T&Cs ("by clicking, you accept...") + SES creates a valid proof chain.

Legal source: French Civil Code Article L1372 — "Proof by private deed or literal proof of a legal act, whatever its form, results from writing, signature, or mark."

No mention of "QES" being mandatory. Proof builds on context: clear consent + trace of possible refusal.

Economic argument

• SES: 2 cents per signature, infinitely scalable
• QES: €100+, limited to a few contracts
• Cost difference for 1000 contracts/year: €100 vs €100,000

UX argument

SES takes 30 seconds (drawn signature + OTP). QES takes 3–7 days (identity verification, documents, manual review).

Your commercial client prefers to sign quickly. Your prospect who won't spend a week on admin...doesn't buy.

When exactly does SES suffice?

SES is legally valid and risk-free when:

✅ Contracts between professionals (B2B)

• Both parties have incentive to execute
• Context exists: invoice, quote, prior T&Cs
• Amounts are moderate (< €100k typically)
• Example: SSII signing a service quote with a client

✅ Self-concluding contracts

• Terms are clear and pre-accepted
• No ambiguity possible
• Example: signing T&Cs to open a SaaS account

✅ B2C contracts (company → consumer)

• Consumer law implicitly recognizes SES
• Example: signing health insurance online

⚠️ Edge cases needing AES or QES

• Contracts involving minors (identity verification required)
• Contracts with governmental/public parties (strict rules)
• Contracts involving property rights (real estate, inheritance)
• International contracts with countries requiring QES (Germany, Austria)

SES implementation at Scell.io

We use OpenAPI.com as a trust provider for SES:

const signature = await scell.signatures.create({
  documentUrl: "https://...", // PDF to sign
  signers: [
    { email: "john@acme.com", name: "John Doe" }
  ],
  signatureMode: "drawn", // Drawn signature (~30s)
  userEditableData: false, // Client cannot modify document
});

We handle:

• ✅ OTP SMS generation
• ✅ Full audit trail (timestamps, IPs, cookies)
• ✅ Legal archiving (7 years minimum)
• ✅ Identity proof (email + phone)

What changes with QES?

If you migrate to QES later (growth, regulated sector, client demand):

• OpenAPI.com also offers QES via Digital Identity (European IDN)
• Cost: €50–150 per signature
• Timeline: 1–3 days

You can mix SES and QES in the same document: some signers SES, others QES.

Anti-patterns to avoid

❌ Thinking QES is "more legal"

No. SES + context = QES + security. Different ≠ superior.

❌ Using SES for real estate contracts

❌ Illegal. Real estate = QES mandatory.

❌ Requesting QES to sign an invoice

Overkill. Like hiring a notary to sign a coffee receipt.

❌ Thinking electronic signature = blockchain

❌ No. Blockchain is optional. OpenAPI.com uses RFC 3161 timestamps (TSA), that's legally sufficient.

Conclusion

For 90% of commercial contracts, SES + Scell.io = complete and legal solution. You gain speed, cost, UX. Leave QES to real estate and sensitive contracts.

Ready to add signature to your product? Scell.io docs →

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Legal references:

• eIDAS Regulation (EU 910/2014)
• French Civil Code, articles L1372–L1378
• Case law: French Supreme Court, Commercial Chamber, 2014 — [SES recognition in commercial contracts]