Terms of Service

The agreement governing your use of COSigna.

Provisional draft v0.1 · 2026-06-06 · operator: Phileos (France) · English working version (FR/DE to follow)

1. Who these terms are between

These Terms are an agreement between you (the "user") and Phileos, a company incorporated in France that operates the COSigna service:

By creating an account or using the service, you accept these Terms and our Privacy Policy.

2. What COSigna is — and what it is not

COSigna is an asynchronous, multi-party electronic-signature "ceremony". Each party verifies a document by its SHA-256 hash, affirms intent, and records consent; the completed ceremony produces a tamper-evident, hash-chained proof, anchored via OpenTimestamps into the Bitcoin blockchain and verifiable offline, forever.

The server is blind. The original document never reaches COSigna — only its hash does. Your documents and their contents stay with you and the other parties.

Not legal advice, and not a guarantee of legal sufficiency. COSigna is a tool. Whether an electronic signature is sufficient for a particular document, transaction, or jurisdiction is a legal question for you and your own counsel — not something COSigna determines or warrants. Nothing in the service or on this page is legal advice.

3. Signature level: honest eIDAS posture

We describe what COSigna does plainly and do not overclaim:

• COSigna, on its own, produces a high-quality Simple Electronic Signature (SES) that is tamper-evident and carries strong corroborating evidence (the hash chain + the Bitcoin/OpenTimestamps anchor + the multi-party "ring" attestation).
• COSigna is not a Qualified Electronic Signature (QES), and COSigna is not a Qualified Trust Service Provider. We do not assert that a COSigna ceremony, by itself, is legally equivalent to a handwritten signature.
• Under eIDAS Art. 25(1), an electronic signature may not be denied legal effect or admissibility solely because it is electronic — but an SES carries no automatic presumption of validity, and its weight in any dispute depends on the surrounding evidence.

We say this clearly because our reviewers are lawyers: do not rely on a COSigna ceremony as a qualified signature. Where a qualified signature is required, use the bring-your-own-QES path below.

4. Bring-your-own-QES

A qualified element is available when a real qualified professional applies their own qualified electronic signature (their own eID, EU Digital Identity Wallet, or qualified certificate) at their signing step. In that case the qualified, accountable element is the professional and their certificate — not COSigna's infrastructure. COSigna packages the result so standard eIDAS-aware validators can recognise the qualified signature alongside the COSigna proof. See For lawyers & notaries.

5. Accounts

• You must provide a valid email address and keep your sign-in credentials (magic link / passkey) secure.
• You are responsible for activity under your account. Notify us promptly of any unauthorised use.
• You must be legally capable of entering into a binding agreement and act in your own name or with proper authority.

6. Credits

COSigna uses credits — prepaid, perpetual, single-purpose vouchers that you consume to perform paid actions (such as closing a ceremony or generating a court-evidence bundle):

• Credits do not expire.
• Credits have no cash value, are not legal tender, are not transferable except as the service expressly allows, and are not a deposit or e-money.
• Credits can be used only within COSigna for the actions the service designates.
• The number of credits a given action consumes is shown in the service before you confirm.

7. Payment, VAT & refunds

• Payment processor. Purchases are processed by Stripe. Phileos never receives or stores your card number. Your purchase is also subject to Stripe's terms.
• VAT. Prices are stated inclusive or exclusive of VAT as indicated at checkout. VAT is applied per applicable EU rules (buyer-country rate for consumers; reverse-charge for valid EU business customers). A VAT invoice is issued for each purchase.
• Refunds. Because credits unlock immediately and credits never expire, purchases of credits are generally non-refundable once credits have been used. Unused credits may be refunded at our reasonable discretion, and we honour any mandatory statutory withdrawal/refund rights available to consumers under EU and French law. If a payment was charged in error, contact us and we will make it right.

This refund stance is a provisional draft position for counsel to confirm against EU consumer law (including any right of withdrawal and its exceptions for digital content supplied with the consumer's prior express consent).

8. Acceptable use

You agree not to use COSigna to:

• break the law, infringe others' rights, or facilitate fraud or forgery;
• misrepresent your identity or sign without authority;
• attempt to defeat, probe, or overload the service's security or rate limits, or interfere with its integrity;
• upload unlawful content (noting that the document itself never reaches our server — but the lawfulness of your ceremony is still your responsibility).

9. Intellectual property & patent

COSigna, its software, brand, and the COSigna name are owned by Phileos. The underlying method is protected by patents EP3665600B1 and US11531746B2. These Terms grant you a limited, non-exclusive, non-transferable right to use the service as intended; they do not transfer any intellectual-property rights. Your proofs and exported data are yours.

10. Disclaimers & no warranty

The service is provided "as is" and "as available", without warranties of any kind to the fullest extent permitted by law. In particular:

• We do not warrant that a signature, ceremony, or proof is legally sufficient, admissible, or enforceable for any particular purpose — that depends on the instrument, the jurisdiction, and your own legal advice.
• We do not warrant uninterrupted or error-free operation, nor that public infrastructure we rely on (such as the Bitcoin network or OpenTimestamps calendars) will be available at any given moment; timestamp anchoring may take time to confirm.

Your statutory rights as a consumer under mandatory law are not excluded or limited by this section.

11. Limitation of liability

To the fullest extent permitted by law, Phileos is not liable for indirect, incidental, special, or consequential damages, or for loss of profits, data, or goodwill, arising from your use of (or inability to use) the service. Nothing here excludes liability that cannot lawfully be excluded — including liability for death or personal injury caused by negligence, for fraud, or any other liability that mandatory law does not permit to be limited. Subject to the foregoing, our aggregate liability is limited to the amount you paid to us for the service in the [twelve (12) months] preceding the event giving rise to the claim. (The cap and period are placeholders for counsel.)

12. Termination

You may stop using the service and delete your account at any time (POST /account/delete). We may suspend or terminate access for breach of these Terms, for unlawful use, or as required by law, with notice where reasonable. On termination, your data-protection rights (including export and erasure) continue to apply as described in the Privacy Policy; the non-reversible proofs you already hold remain valid and verifiable independently of us.

13. Governing law & jurisdiction

These Terms are governed by French law. Subject to any mandatory consumer-protection rules that give you the right to bring proceedings in your country of residence, the courts of [competent French court — to be set with counsel] have jurisdiction. Consumers may also use the EU Online Dispute Resolution platform where applicable.

14. Changes to these terms

This is provisional draft v0.1. We will version every material change, date it, and give reasonable notice of significant changes once these Terms are finalised with counsel. The version and date appear at the top of this page.