How it worksSecurityFor developersCompliance
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eIDASQualified Electronic Signatures, issued through ZealiD

Upload the PDF. We hand it back qualified.

Signature space, hashing, certificates, timestamps, long-term validity, encrypted archiving — all of it ours. The only signature that stands equal to ink in all 27 EU member states, and you never touch a single byte of cryptography.

Sign your first documentRead the API docs
  • ZealiD — Qualified Trust Service Provider
  • XChaCha20-Poly1305 at rest
  • EU-only data residency
  • PAdES B-LTA
lease-agreement-2026.pdf

Your document

Residential lease · 2026

Signature field

Dr. A. Meyer · verified by ZealiD

weSign did this

  1. Receivedcontract.pdf · 412 KB
  2. Prepared & hashed/ByteRange · SHA-256
  3. Certified by ZealiDQSCD · qualified cert
  4. Sealed & archivedPAdES-B-LTA · encrypted

Anyone can verify

Signature valid

Qualified certificate · ZealiD AB

Level
PAdES-B-LTA
Signed
2026-08-07 09:41 UTC
Timestamp
Qualified (TSA)
Integrity
Untouched since signing
Valid until
Indefinite (LTV)
Only this left our servers

9f2b8c41d7e05a63bb14f8907c2d3e5a6f81b0c94d27ae3f5b6c8d1029e4af73

ETSI EN 319 142-1ETSI EN 319 422 timestampsEN 419241-2 QSCDGDPRISO 27001

How it works

One upload in. A legally binding document out.

A qualified signature is dozens of moving parts — certificate chains, byte ranges, revocation data, timestamps, trust lists. We carry all of it. And your part in it never grows beyond one upload and two taps on your phone.

  1. UploadYou

    Drop in the final PDF. No placeholder fields, no certificates, no crypto library on your side.

    1 request

  2. QR codeweSign

    We ask ZealiD to release your qualified certificate chain and hand you back a QR code. Nothing has touched the document yet.

    QR 1 of 2

  3. AuthorizeYou

    You scan that code and approve inside the ZealiD app. The approval goes straight to ZealiD — we are never in the middle of it.

    your phone

  4. ReleaseZealiD

    ZealiD checks your approval and releases your qualified certificate chain to us. Your signing key stays inside their certified hardware.

    x5c chain

  5. PrepareweSign

    We open the signature dictionary inside the PDF and reserve the exact byte range the signature will occupy.

    /ByteRange

  6. HashweSign

    The reserved ranges are digested into a single SHA-256 hash — 64 characters that reveal nothing about the file.

    SHA-256

  7. QR codeweSign

    A second QR code, this time for the signature itself. It is bound to that one hash and to nothing else.

    QR 2 of 2

  8. AuthorizeYou

    You scan and approve again, and again the tap lands on ZealiD's platform. This is the moment the law treats as your own hand on the page.

    your phone

  9. CertifyZealiD

    ZealiD signs the hash with your qualified certificate on certified hardware and hands the signature back. The document itself never leaves our side.

    QSCD

  10. SealweSign

    The signature, certificate chain, revocation data and a qualified timestamp are embedded back into the PDF.

    PAdES-B-LTA

  11. YoursYou

    You get a file that validates in Adobe Reader, in court, and in ten years — plus an encrypted copy in your vault.

    LTV ready

  12. everything else runs on our side
Identity verification happens once. Every signature after that is one call and two taps.

Security architecture

Your document never leaves the vault.

ZealiD verifies people and issues qualified certificates. Your identity lives with them, your document lives with us, and the only thing that travels between the two is a number.

Stays inside weSign

encrypted
  • The PDF itselfevery byte, every page
  • Document contentstext, images, metadata
  • The sealed resultsignature, chain, timestamp
  • Encryption keysper-object, HSM-wrapped
Signing historyAppend-only, and deliberately in the clear — it records when something happened, never what the document said. Export it as evidence any time.

Sent to ZealiD

the whole list
One SHA-256 hash

9f2b8c41d7e05a63bb14f8907c2d3e5a6f81b0c94d27ae3f5b6c8d1029e4af73

A hash is a one-way fingerprint. It proves the file has not changed by a single byte, and it reveals nothing about what the file says. ZealiD signs that number — not your contract.

Who you are is already theirs to hold. ZealiD verified your passport and liveness to issue the certificate, and that evidence stays on their side under eIDAS — weSign never asks for it and never stores it.

irreversible, by construction

At rest

XChaCha20-Poly1305

Every document, sealed result and object key is encrypted on its own with a unique nonce and an authentication tag. Corruption and tampering are detected on read, not on trust.

In transit

TLS 1.3, EU endpoints

Requests terminate inside the EU. The payload that reaches the Trust Service Provider is a digest and a signing intent — nothing that can be reconstructed into a document.

Key custody

HSM-wrapped envelopes

Object keys are wrapped by a root key that never leaves hardware. No engineer, and no support session, can decrypt a customer document.

Residency

EU only, always

Storage, processing, backups and logs stay within the European Union. Nothing is replicated to a region outside the EEA, under any circumstance.

Two surfaces

For your team, and for your code.

The same qualified signature, whether a person clicks it or a service requests it. Nothing about the legal outcome changes.

lease-agreement-2026.pdf

A. Meyer

09:41

patient-consent-4471.pdf

Klinik Nord

09:12

power-of-attorney.pdf

J. Kowalski

08:55

supplier-nda-q3.pdf

Contoso GmbH

Yesterday

board-resolution-12.pdf

Draft

Yesterday

Folders, search and retention rules across every signed document

One identity check per signer — reused for every signature after

Append-only audit trail, exportable as evidence

same legal weight, either way
Open the workspace

Who signs with weSign

Built for the documents that actually matter.

If a document carries consequences, it deserves the highest signature level European law defines.

Companies

Close deals the same day, across borders, without a courier.

Supplier contracts · NDAs · board resolutions

Public sector

Meet eIDAS obligations with the signature level regulation asks for.

Permits · procurement · citizen decisions

Doctors & clinics

Consent that holds up, with patient data encrypted per record.

Patient consent · referrals · prescriptions

Lawyers & notaries

Evidence-grade signatures with a timestamped, exportable trail.

Powers of attorney · settlements · filings

Landlords

A tenant signs from a phone in minutes — no printer, no scanner.

Leases · handover protocols · terminations

Accountants

Signatures that stay verifiable for as long as you must keep them.

Annual reports · filings · audit sign-offs

27EU member states recognise itcross-border by law
1:1Legal weight against inkeIDAS Art. 25(2)
10+Years verifiable after signingPAdES-LTA, without us
0Documents stored in plaintextencrypted per object

Compliance

Nothing here is self-declared.

Every claim on this page maps to a European standard, an audited Trust Service Provider, or a published specification you can read yourself.

  • eIDAS Regulation

    (EU) 910/2014

    A qualified electronic signature has the equivalent legal effect of a handwritten signature.

  • PAdES B-LTA

    ETSI EN 319 142-1

    Signature, certificate chain, revocation data and archive timestamp embedded in the PDF itself.

  • Qualified timestamps

    ETSI EN 319 422

    Proof of when the signature existed, issued by a qualified time-stamping authority.

  • QSCD

    EN 419241-2

    The signing key lives on a qualified signature creation device under the signer's sole control.

  • Information security

    ISO/IEC 27001

    Documented ISMS covering key custody, access control and incident response.

  • Data minimisation

    GDPR

    The Trust Service Provider receives a digest. Identity data stays with them; we never collect a second copy.

Straight answers

Before you ask us.

The questions legal and engineering teams ask before they sign anything themselves.

Is this really equal to a handwritten signature?

Yes. Article 25(2) of the eIDAS Regulation states that a qualified electronic signature has the equivalent legal effect of a handwritten signature, and every EU member state must recognise one issued in any other. That equivalence only applies to the qualified level — the one weSign issues.

What happens to our documents if weSign disappears?

Nothing. A PAdES-LTA file is self-contained: the signature, the full certificate chain, the revocation evidence and an archive timestamp are embedded inside the PDF. It validates in Adobe Reader or any conformant validator with no call to our servers. You can export everything at any time.

Do signers need a card reader or a national eID?

No. ZealiD verifies identity remotely — a passport or national ID plus a liveness check, once. The qualified certificate is then issued and the signing key stays on a QSCD under the signer's sole control. Every later signature is a confirmation on their phone.

Can we keep the documents in our own storage?

Yes. The API returns the sealed PDF in the response; storing it with us is optional. If you do use the vault, each document is encrypted as its own object with XChaCha20-Poly1305 and stays inside the EU.

How much of the PDF work is left to us?

None. You do not create signature fields, reserve byte ranges, compute digests, handle certificates or manage keys. You upload a finished PDF and receive a signed one — that is the entire integration surface.

Your next contract can be qualified-signed before lunch.

Verify a signer once, upload a PDF, and get back a document that holds anywhere in the Union. The sandbox needs no card and no real identity.

Start signingTry the sandbox
  • No card for the sandbox
  • Signer onboarding in minutes
  • Cancel any time