Pillar guide · updated 2026

The complete guide to electronic signatures under eIDAS

Everything you need to know to sign contracts, NDAs, mandates and proposals electronically and legally: what the law says, how to pick the right signature, and the practical tools to get started today.

  • eIDAS compliant
  • Written for founders, not lawyers
  • Practical examples for each tier
  • Free tools to get started

What is an electronic signature (and why it isn't always a 'digital signature')

An electronic signature is any data in electronic form attached to, or logically associated with, other electronic data and used by the signer to sign. In some EU countries 'digital signature' refers specifically to QES (qualified signatures), but in common usage the two terms are synonymous. The legal anchor is the EU eIDAS Regulation 910/2014. Electronic signatures are not less legal than paper ones: context and type determine the evidentiary weight. For most commercial B2B and B2C contracts, a well-handled SES is enough.

The three eIDAS tiers: SES, AES, QES

eIDAS defines three levels. SES (Simple Electronic Signature) covers basic flows: a ticked box, a typed name, a captured handwritten signature. AES (Advanced) requires unique identification of the signer, sole control of the signing means, and tamper detection. QES (Qualified) is an AES created with a qualified signature creation device and based on a qualified certificate from a trust service provider, with the same legal effect as a handwritten signature throughout the EU.

When SES is enough and when you need QES

For commercial proposals, listing agreements, NDAs, freelance contracts, order confirmations, internal policies and consent forms, SES is almost always enough. AES or QES is needed when the law mandates a qualified written form: notarial deeds, real estate transfers in some jurisdictions, specific filings with public administration. When in doubt, AES is a sensible compromise: high evidentiary weight without QES-level cost.

Evidentiary weight in court

Across EU courts, SES is freely assessed by the judge: its weight depends on the quality of the audit trail and on context. AES and QES enjoy a presumption of integrity and signer attribution. In practice, an SES with a strong audit trail (IP, qualified timestamp, open / read / sign events, document hashes) holds up well, because disputing a signature backed by abundant technical evidence is hard.

What a strong audit trail must contain

The audit trail is your evidence: without it, the signature is weak. It must include qualified timestamps, IP address, device and user agent, send / open / read / sign / complete events, hashes of the document before and after signing, and the signer's identity (email, phone, optional OTP verification). YouKont automatically generates a completion certificate with all of the above.

How it works in practice: the typical flow

1) Upload the document (PDF) or generate it from a template. 2) Add signer names, emails and roles. 3) Place the signature fields. 4) Send. The signer receives a secure link, opens the document in any browser, signs with finger or by typing, confirms. The system timestamps the document, archives the signed PDF and generates the signature certificate. You get notified and the contract is done.

In-person vs remote signing

In person, the customer signs on your tablet or phone: ideal for agents, property managers and field sales. Remote, the customer opens the link via email or WhatsApp: ideal for distance deals. Both flows produce the same audit trail. The difference is identification: in person you see the customer; remotely you can add an SMS OTP to strengthen the evidence.

Common mistakes to avoid

Don't paste a picture of your signature into a PDF: it isn't a real electronic signature and produces no audit trail. Don't exchange signed contracts only over WhatsApp: use a platform that generates technical evidence. Don't share email accounts between signers: it makes attribution impossible. Don't delete the completion certificate: it's your primary legal evidence. Never skip the timestamp: without certain date, the signature loses most of its weight.

Retention and archiving

Commercial contracts typically need 10-year retention. The platform must keep the document and its audit trail intact and accessible throughout. YouKont keeps the archive in a secure EU cloud with daily backups and read-only access even if you downgrade or close your account: your signed contracts remain yours.

Use cases by industry

Real estate agencies: listing agreements, offers, lease contracts. Short-term rental property managers: guest contracts, house rules, releases. Professional services: engagement letters, quotes, NDAs. B2B sales: commercial proposals, orders, master agreements. HR: collaboration agreements, internships, confidentiality. Each industry has specific needs that YouKont covers with ready-made templates.

How to choose an electronic signature platform

Look for: declared eIDAS compliance, complete and downloadable PDF audit trail, qualified timestamping, in-person and offline signing, reusable templates, CRM integrations, transparent pricing with a real free plan (not just a trial), EU-based data centres, multilingual support. Be wary of vendors that don't clearly state which signature type (SES / AES / QES) they actually deliver.

GDPR and data protection

Personal data collected during signing (name, email, IP, optional phone number) is personal data under the GDPR. You need a lawful basis (typically contract performance) and must inform the signer. Choose a provider with EU servers, an available DPA and clear retention policies. YouKont is EU-based and provides a standard DPA to all customers.

What it really costs

SES starts at €0 (free plan) and scales with volume and seats. QES with qualified certificate has yearly per-certificate costs (typically €30-50/year for a remote certificate). For most SMEs, a SaaS plan combining SES and AES covers 95% of use cases at low cost. See YouKont pricing for a transparent comparison.

Where to start

Start today with one small, repeatable use case: a proposal template or an NDA. Measure time saved (usually 2-4 days per contract vs paper) and then extend to other flows. With YouKont you can start free in 60 seconds and use 14 days of Pro without a card to test everything at scale.

Frequently asked questions

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