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OS Sign — Terms of Service

Effective: 20 August 2026

These are the Terms of Service (“Terms”) for OS Sign, an electronic signature service operated by The OS Company, a company registered in the United Kingdom (“we”, “us”, “our”, “The OS Company”). Our primary domain is theoscompany.co.uk. OS Sign runs at sign.theoscompany.com.

Contact: shachar@theoscompany.com

These Terms apply to two groups of people:

  • Account Holders — internal team members and their organisation who create and send documents through OS Sign.
  • Signers — people who receive an emailed link to sign a document and do not hold an account.

Section 9 (“Signer Terms”) is written directly for Signers. If you are a Signer, read that section carefully — it governs you even though you never create an account.

By using OS Sign, you agree to these Terms. If you do not agree, do not use OS Sign.

1. Definitions

  • “Account Holder” means a person or organisation with a login to OS Sign who uploads, sends, or manages documents.
  • “Document” means any file, contract, or record uploaded to OS Sign for signature.
  • “Signer” means a person who receives a link to a Document and signs it, with or without an account.
  • “Audit Trail” means the record OS Sign keeps of actions taken on a Document — for example, when it was sent, viewed, and signed, and from which IP address.
  • “Service” means the OS Sign platform, including the website, the signing workflow, storage, and related email notifications.
  • “Personal Data” has the meaning given in UK GDPR.
  • “we”, “us”, “our” means The OS Company.
  • “you”, “your” means the person or organisation using the Service, whether an Account Holder or a Signer.

2. Who We Are

The OS Company operates OS Sign.

The OS Company is the data controller for Personal Data we process for our own purposes in operating the Service — for example, Account Holder registration data, billing data, and data we generate about the security and integrity of the Service. In relation to the content of Documents, and the names, email addresses, signatures and IP addresses of Signers collected because an Account Holder chose to send them a Document, the Account Holder is the data controller and The OS Company is the data processor, acting only on the Account Holder’s instructions as set out in these Terms and in our Data Processing Agreement (available on request), which forms part of these Terms for any Account Holder who processes Personal Data of a Signer through the Service. Where we determine the purposes and means of any processing of Signer data ourselves — for example, security monitoring, audit-trail generation, or fraud prevention — we act as controller for that specific processing only.

OS Sign is built on Documenso, an open-source project licensed under AGPL-3.0. We run our own fork of that software on our own servers. We are not Documenso, and Documenso does not operate this Service.

3. The Service

OS Sign lets an Account Holder upload a Document, send it to one or more Signers by email, and collect signatures. For each Document, OS Sign keeps an Audit Trail of the key actions taken.

The Service runs on servers in London, United Kingdom (AWS Lightsail, eu-west-2 region). Documents and related data stay in the UK/EU. We use Cloudflare to secure the connection between your browser and our servers (TLS encryption), and Google Workspace to send emails such as signing invitations and notifications.

We do not use the Service for analytics or marketing, and we do not sell your data. See our Privacy Policy for full detail on how we handle Personal Data.

4. Data We Process

To provide the Service, we process:

  • Names and email addresses of Account Holders and Signers.
  • IP addresses recorded at key actions (sending, viewing, signing).
  • Signature images or typed signatures.
  • The content of Documents you upload or sign.
  • Audit Trail data: timestamps, IP addresses, and the actions taken.

We store this data in a PostgreSQL database on our London server. We do not use it for any purpose beyond providing the Service, and we do not sell it or share it with third parties for marketing.

5. Acceptable Use

You must not use OS Sign to:

  • Upload or send a Document you do not have the legal right to send.
  • Impersonate another person, or send a Document that misleads a Signer about who sent it or what they are agreeing to.
  • Upload unlawful content, including content that infringes someone else’s rights, is fraudulent, or is used to harass or defraud another person.
  • Try to gain unauthorised access to the Service, another user’s account, or another user’s Documents.
  • Interfere with the normal operation of the Service — for example, by overloading it, scanning it for vulnerabilities without permission, or attempting to bypass its security controls.
  • Use the Service to process Personal Data unlawfully, or in a way that breaches UK GDPR or the Data Protection Act 2018.

We may suspend or terminate access for any account that breaches this section. See Section 12 (Termination).

You will indemnify us against any loss, cost, liability or expense (including reasonable legal costs) we incur as a result of a third-party claim arising from your breach of this Section 5, or from a Document you sent or signed in breach of any law or another person’s rights.

6. Account Holder Terms

This section applies to Account Holders.

6.1 Registration. You must give accurate information when you set up an account, and keep it up to date.

6.2 Account security. You are responsible for keeping your login credentials confidential and for all activity under your account. Tell us immediately at shachar@theoscompany.com if you believe your account has been compromised.

6.3 Your Documents. You own the content of the Documents you upload. You are responsible for making sure you have the right to send each Document, and that sending it does not breach any law, contract, or third party’s rights.

You grant us a non-exclusive, worldwide, royalty-free licence to host, store, copy, transmit and display the content of your Documents solely to the extent necessary to provide the Service to you and your Signers.

6.4 Recipient consent. When you send a Document for signature, you are responsible for making sure each Signer has agreed, or is entitled under applicable law, to sign electronically. Section 8 explains the legal status of signatures produced by OS Sign — read it before relying on the Service for a transaction that requires a specific signing formality.

6.5 Internal use. OS Sign is provided for The OS Company’s internal team and any organisation we have agreed to provide it to. Access is granted at our discretion and may be limited to named individuals.

6.6 Fees. Where we agree to provide the Service to your organisation for a fee, the fee, billing frequency, and payment terms will be set out in a separate order or agreement between us. Fees are exclusive of VAT, which we will add where applicable. If a fee is not paid when due, we may suspend your access to the Service until payment is received, without prejudice to Section 12.2.

6.7 Confidentiality. We will treat the content of your Documents as confidential and will not access, review or disclose it except: to provide the Service, to comply with a legal obligation, to enforce these Terms, or with your consent. You must keep confidential any non-public information about the Service that we mark as confidential or that would reasonably be understood to be confidential.

6.8 Security incidents. If we become aware of a Personal Data breach affecting Documents or data processed on your behalf, we will notify you without undue delay and provide the information reasonably necessary for you to meet your own notification obligations under UK GDPR.

7. Document Retention and the Audit Trail

7.1 Retention. We keep Documents and their Audit Trail for as long as your account is active, or for the retention period we separately agree with your organisation. You are responsible for keeping your own copy of any Document that matters to you — we recommend downloading a signed copy once execution is complete. Where your account has been inactive for 24 months, we will contact you before deleting your Documents, and will delete them within a further reasonable period if we do not hear from you, except where we must retain a record as set out in Section 7.3.

7.2 The Audit Trail. For every Document, OS Sign records who sent it, who viewed it, who signed it, when each of these happened, and the IP address recorded for each action. This Audit Trail is attached to, or made available alongside, the completed Document. It is the evidence of what happened during signing — keep it with the signed Document.

7.3 Deletion. If your account is closed, or you ask us to delete a Document, we will delete it within a reasonable time, except where we must keep a record to meet a legal obligation, resolve a dispute, or enforce these Terms.

8. Electronic Signatures — Legal Status

We want to be direct about what an OS Sign signature is, and what it is not.

8.1 What OS Sign produces. When a Signer signs a Document through OS Sign, the Service captures their signature (drawn or typed) and builds an Audit Trail of the signing process: who signed, when, and from what IP address. We do not represent that this meets the definition of an “advanced electronic signature” under UK eIDAS (Regulation (EU) 910/2014 as it forms part of UK law) — in particular, we do not represent that the signature is created using data that is under the signatory’s sole control within the meaning of Article 26(c). Our audit certificates are self-signed by our own systems, not issued by an accredited trust service provider.

8.2 What OS Sign does not produce. OS Sign does not produce a “qualified electronic signature” under UK eIDAS. A qualified electronic signature requires a qualified certificate from an accredited trust service provider and a qualified signature-creation device. OS Sign does not use either. If a transaction legally requires a qualified electronic signature — this is uncommon, but it applies to some specific legal acts — OS Sign is not the right tool, and you should get your own legal advice before using it for that transaction.

8.3 Validity under English law. Under English law, an electronic signature is generally capable of being used to execute a document, including a contract, provided the person signing intends to authenticate the document and the formality required for that particular document is met. Section 7 of the Electronic Communications Act 2000 confirms that an electronic signature, and the certification of that signature, is admissible in evidence in relation to any question about the authenticity or integrity of the signed document. By sending or signing a Document through OS Sign, you and the Signer both accept execution by electronic signature for that Document, on the basis of the Audit Trail this Service produces.

8.4 Documents you must not sign through OS Sign. Do not use OS Sign to execute: a will or codicil (the Wills Act 1837 requires a wet-ink signature witnessed in person by two witnesses); a disposition of registered land or a document required to be a Qualified Electronic Signature by HM Land Registry (OS Sign does not produce a Qualified Electronic Signature — see Section 8.2); or a deed, unless you have taken your own legal advice on how to satisfy the witnessing requirement for deeds and have done so outside the OS Sign signing flow. For any other Document, it is the Account Holder’s responsibility to judge whether OS Sign’s form of signature is appropriate — for example, most commercial contracts, NDAs and letters are fine. If you are unsure, take legal advice before using OS Sign for that Document.

9. Signer Terms

This section is written for you if you received a link by email to sign a Document. You do not need an account to sign, but by opening the link and signing, you agree to the parts of these Terms that apply to you — this section, and Sections 1, 3, 4, 5, 8, 12.3, and 13.

9.0 How you accept these Terms. We will display a link to the parts of these Terms that apply to you on the signing page, before you complete your signature. Completing your signature after that link has been shown to you constitutes your acceptance of Section 9 and the other sections listed above.

9.1 Who sent you the link. OS Sign is the platform that delivers and records your signature. The Document itself, and the request to sign it, come from the Account Holder who sent it to you — not from The OS Company. We do not check the content of what you are signing.

9.2 What happens when you sign. When you open the link and complete the signing steps, OS Sign records that you viewed and signed the Document, the time this happened, and the IP address your device used. Your signature (drawn or typed) and this record together become the Audit Trail attached to the Document. By signing, you confirm you are at least 18 years old and have the legal capacity to enter into the Document you are signing. See Section 8 for what this signature legally is, and is not.

9.3 Check before you sign. Read the Document before you sign it. Signing through OS Sign has the same legal effect as signing a paper copy, once you and the sender have agreed to use electronic signature for that Document (see Section 8.3). If you are not sure what you are agreeing to, ask the person who sent it to you before you sign.

9.4 Your data. We process your name, email address, IP address, and signature as described in Section 4, in order to deliver and record your signature. In this processing, we act on the instructions of the Account Holder who sent you the Document: the Account Holder is the data controller for this data, and we are the data processor (see Section 2). We are the data controller only for data we process for our own purposes, such as the security and integrity of the Service. See our Privacy Policy for more detail, including how to exercise your rights under UK GDPR — you may need to contact the Account Holder, as well as us, to exercise those rights fully.

9.5 Access to the Document. After signing, you may be given the option to download a copy of the completed Document. We recommend you keep your own copy. If your access to the Document later expires, contact the Account Holder who sent it to you, or write to shachar@theoscompany.com.

9.6 No account, no marketing. Signing a Document does not create an account for you, and we do not use your details for marketing.

10. Availability

We aim to keep OS Sign available, but we do not promise it will be. The Service is provided “as is” and “as available,” with no service level agreement, to Account Holders and Signers. We do not guarantee that OS Sign will be uninterrupted, error-free, or available at any particular time.

This Section 10 and Section 11 apply as between us and our contracting parties (Account Holders and Signers) only. We do not accept, and expressly disclaim, any duty of care to any person who is not a party to these Terms in respect of a Document processed through the Service, including a person who relies on a Document without having used OS Sign themselves. Nothing in these Terms is intended to confer a benefit on, or be enforceable by, a third party under the Contracts (Rights of Third Parties) Act 1999.

We may carry out maintenance, make changes to the Service, or suspend it, at our discretion, and will try to give reasonable notice where practical.

11. Liability

11.1 Nothing excluded that the law does not allow us to exclude. Nothing in these Terms limits or excludes our liability for death or personal injury caused by our negligence, for fraud or fraudulent misrepresentation, or for anything else that cannot lawfully be limited or excluded under the Unfair Contract Terms Act 1977, the Consumer Rights Act 2015, or any other applicable law. Where a Signer is acting as a consumer for the purposes of the Consumer Rights Act 2015, nothing in Section 11.2 excludes or restricts a right that Act gives that Signer, and Section 11.2 applies to that Signer only to the extent it is fair within the meaning of that Act.

11.2 Limits that do apply. Subject to Section 11.1, and to the extent permitted by law:

  • We are not liable for indirect or consequential loss, including loss of profit, loss of business, or loss of data, arising from your use of the Service.
  • We are not liable for the content of any Document, or for a decision made by an Account Holder or Signer to send, sign, or rely on a Document.
  • We are not liable for loss caused by a Document being sent to the wrong person, or by a Signer misusing or misunderstanding what they are signing.
  • Our total liability to any Account Holder, or to any Signer, arising out of or in connection with the Service, in any 12-month period, is limited to the fees that Account Holder paid us for the Service in that period (or £[X], being a sum proportionate to the potential harm of a signature-integrity failure, if no fees were paid), except where the Signer is a consumer, in which case Section 11.1 applies.

11.3 Reasonableness. Both parties agree these limits are reasonable, given that OS Sign is provided without a service fee to most Account Holders, and given the nature of the Service described in Section 10.

12. Termination

12.1 By you. An Account Holder may stop using the Service, or ask us to close their account, at any time by writing to shachar@theoscompany.com.

12.2 By us. We may suspend or close an account, with or without notice, if we reasonably believe you have breached Section 5 (Acceptable Use), if required by law, or if we decide to discontinue the Service. Where practical, we will give notice and a reasonable chance to export your Documents first.

12.3 What happens on termination. Sections 1, 4, 7, 8, 9, 11, 13, and 14 survive termination. We will handle any remaining Personal Data in line with our Privacy Policy and our retention obligations under Section 7.

13. Changes to These Terms

We may update these Terms from time to time — for example, to reflect a change in the law or in how the Service works. If we make a material change (for example, a change that reduces your rights or increases your obligations), we will give Account Holders reasonable notice, such as by email or a notice within the Service, before the change takes effect. Continued use of OS Sign after a change takes effect means you accept the updated Terms.

The version of these Terms in force at the time a Document was sent for signature governs that Document’s signing process.

14. Governing Law and Jurisdiction

These Terms, and any dispute arising out of or in connection with them or the Service, are governed by the law of England and Wales. The courts of England and Wales have exclusive jurisdiction over any such dispute.

If you are a consumer habitually resident in a country other than England and Wales, this clause does not deprive you of any protection given to you by the mandatory law of that country, and nothing in this clause prevents you from bringing proceedings in the courts of that country where the law of that country entitles you to do so.

15. Contact

Questions about these Terms, or about OS Sign generally, go to:

The OS Company Email: shachar@theoscompany.com Web: theoscompany.co.uk

The OS Company is [FULL REGISTERED NAME], a company registered in England and Wales under company number [XXXXXXXX], with its registered office at [FULL REGISTERED OFFICE ADDRESS]. [VAT number, if registered: GB XXXXXXXXX.]

16. Boilerplate

16.1 Third party rights. Except as set out in Section 10, a person who is not a party to these Terms has no right to enforce any of their terms, and nothing in these Terms confers a benefit on a third party for the purposes of the Contracts (Rights of Third Parties) Act 1999.

16.2 Entire agreement. These Terms (together with our Privacy Policy and any Data Processing Agreement) are the entire agreement between us in relation to the Service and supersede any prior discussion.

16.3 Severability. If a court finds part of these Terms unenforceable, the rest continues to apply.

16.4 Assignment. We may assign these Terms in connection with a sale or reorganisation of our business. You may not assign these Terms without our consent.

16.5 Force majeure. Neither party is liable for a failure to perform caused by circumstances beyond its reasonable control.

16.6 Notices. Notices to us must be sent to shachar@theoscompany.com. Notices to you will be sent to the email address on your account, or, for a Signer, the email address the Document was sent to.

OS Sign is built on Documenso (AGPL-3.0), an open-source project. The OS Company operates its own fork of that software on its own infrastructure and is solely responsible for the Service described in these Terms.