Terms of Service

Last updated: August 23, 2026

These Terms of Service ("these Terms") set out the conditions of use for Proof Stamp ("the Service"). Users ("Users") agree to these Terms before using the Service.

This English translation is provided for convenience only. Where any discrepancy exists between this translation and the Japanese original, the Japanese original governs.

Article 1 (Application)

These Terms apply to all relationships between a User and the operator of the Service ("the Operator") relating to use of the Service.

Article 2 (Description of the Service)

The Service records the hash value of a file uploaded by a User as a timestamp on the Bitcoin blockchain, providing an objective proof that the data existed at a specific point in time.

The Service does not guarantee or certify that the content of any uploaded data is true, accurate, or lawful. It functions solely as a mechanical technical infrastructure that records the fact that "this data existed at this point in time."

Article 3 (Account Registration)

1. Users shall register an account using truthful and accurate information.
2. Users are responsible for properly managing their registered email address, login links, authentication tokens, and any other credentials. The Operator bears no responsibility for damages arising from inadequate management, misuse, or use by a third party of such credentials.
3. If registered information changes, the User shall promptly update it.

Article 4 (Prohibited Conduct)

When using the Service, Users shall not:

• Act in violation of any law or public order and morals
• Engage in, or in conduct related to, criminal activity
• Infringe a third party's intellectual property rights, right of publicity, privacy, reputation, or other rights
• Upload data intended to harass, defame, or threaten a third party
• Place excessive load on the Service's servers or network, or otherwise interfere with its operation
• Reverse-engineer the Service, gain unauthorized access, or exploit vulnerabilities
• Engage in any other conduct the Operator deems inappropriate

Article 5 (Fees and Payment)

1. Fees, payment methods, and payment timing for paid plans are as set out in the Legal Disclosure page.
2. Paid plans are auto-renewing subscriptions billed through our payment processor (Stripe, Inc.); the subscription renews automatically unless cancelled.
3. No refunds are issued for already-paid periods, except where required by law.

Article 6 (Cancellation / Account Closure)

Users may cancel their plan at any time from "Plan" → "Manage Billing" on their account page. Once cancellation is complete, no further charges will occur. To delete your account entirely, please contact Customer Support.

Article 7 (Handling of Uploaded Data)

Copyright and any other rights in data uploaded by a User remain with that User. The Operator handles such data only to the extent necessary to provide the Service (building the timestamp proof, generating previews, issuing certificates, etc.) and for no other purpose.

Article 8 (Disclaimer)

1. The Service is provided "as is," with no warranty, express or implied, as to fitness for a particular purpose, accuracy, or completeness.
2. Incorporation into the Bitcoin blockchain (finalization of the timestamp) depends on external calendar servers and the state of the Bitcoin network; the Operator does not guarantee how long finalization will take.
3. Except where caused by the Operator's willful misconduct or gross negligence, the Operator bears no liability for any damages a User incurs from using the Service.
4. The Service makes no warranty whatsoever as to the truthfulness or lawfulness of the content of any uploaded data.

Article 9 (Changes, Suspension, or Termination of the Service)

The Operator may change the content of the Service, or suspend or terminate it, without prior notice to Users. The Operator bears no liability for any resulting damages.

Article 10 (Changes to These Terms)

The Operator may amend these Terms without notice to Users where it deems necessary. Amended Terms take effect once posted on the Service.

Article 11 (Governing Law / Jurisdiction)

These Terms are governed by the laws of Japan. Any dispute arising in connection with the Service shall be subject to the exclusive jurisdiction of the court having jurisdiction over the Operator's location, as the court of first instance.

Article 12 (Contact)

For inquiries regarding these Terms, please contact Customer Support.