About ULSN

The Unique Licence Serial Number (ULSN) Registry is the standardised identification and verification system for copyright licences worldwide.

ULSN was established to solve a fundamental problem in e-commerce: there was no universal way to verify that a seller has a legitimate licence to use copyrighted content on their products. Rights holders filed complaints, platforms processed takedowns, sellers lost listings — and no one could easily prove who was authorised and who was not.

How ULSN works

When a copyright licence is agreed between a rights holder (or their authorised representative) and a licensee, the issuing organisation generates a ULSN. This number is permanently recorded in the registry and can be verified by anyone — instantly, for free, with no account required.

Each ULSN encodes the year of issuance and an opaque identifier. No personal information about the rights holder is revealed in the number itself. Verification returns only the information necessary to confirm the licence is genuine: the licensee name, their country, the number of works covered, the attribution credit, and the licence status.

Who operates ULSN?

The ULSN Registry is operated by PayPerArt Ltd, a UK-registered company (ICO Registration: ZC064565) specialising in copyright licensing infrastructure. PayPerArt is also the first authorised ULSN issuer.

The registry is designed to be issuer-neutral. Any licensed and vetted organisation can apply to become an authorised ULSN issuer, enabling them to generate verified licence numbers for their own clients through the ULSN API.

Standards and format

Every ULSN follows the format: ULSN-YYYY-XXXXXXXXXXX where YYYY is the year of issuance and the 11 characters form an opaque, tamper-resistant identifier.

There is no published algorithm for generating or validating ULSNs. All verification must go through the official registry. This design ensures that only authorised issuers can create valid numbers, and that every verification is logged and auditable.

Coverage

ULSN currently covers non-performing copyright works including visual art, photography, text and literature, sound recordings, and architectural works. The registry does not cover performing arts rights, which are managed by existing collective management organisations.

Contact

For general enquiries: hello@ulsn.org

For issuer applications: issuers@ulsn.org

For technical / API enquiries: api@ulsn.org

Become an Authorised Issuer

Licensing companies, rights management organisations, and copyright collectives can apply to become authorised ULSN issuers — enabling them to issue verified licence numbers to their own clients and licensees.

Fee Structure

What you get

• Unique issuer code in the ULSN registry
• API access to generate and manage ULSNs programmatically
• Issuer dashboard — view all issued licences, stats, and usage
• Your organisation listed as an authorised issuer on ulsn.org
• Technical support for API integration
• Webhook notifications for licence events (verification lookups, expiry alerts)

Apply

Terms of Service

Last updated: 25 March 2026

1. Registry Services

The ULSN Registry ("Registry") provides copyright licence identification and verification services. The Registry is operated by PayPerArt Ltd ("Operator"), a company registered in England and Wales (ICO Registration: ZC064565).

2. Verification

The public verification service is provided free of charge. Verification results confirm the status of a licence as recorded by the issuing organisation. The Registry does not guarantee the accuracy of information provided by issuers. The Registry is a record of what issuers have reported, not an independent audit of licence validity.

3. Rate Limits

Public verification is subject to rate limiting to prevent abuse. Excessive automated queries may result in temporary or permanent IP blocking. For bulk verification, licensed API access is available to authorised issuers and platform partners.

4. Issuer Responsibilities

Authorised issuers are responsible for the accuracy of information associated with ULSNs they generate. Issuers must maintain documented evidence of copyright holder consent for each licence they record. The Registry reserves the right to revoke issuer access for non-compliance with issuance standards.

5. Data Protection

The Registry processes personal data in accordance with the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act 2018. Public verification results display only the minimum information necessary to confirm licence status. No personal data about rights holders is disclosed through verification unless the rights holder has explicitly chosen to include attribution information.

6. Intellectual Property

The ULSN numbering system, verification infrastructure, and associated trademarks are the property of the Operator. The ULSN format and registry are not open-source. Unauthorised use of the ULSN name, format, or verification infrastructure is prohibited.

7. Limitation of Liability

The Registry is provided "as is". The Operator does not warrant that the service will be uninterrupted or error-free. The Operator is not liable for any loss arising from reliance on verification results. The maximum liability of the Operator for any claim is limited to the fees paid by the claimant in the 12 months preceding the claim.

8. Governing Law

These terms are governed by the laws of England and Wales. Disputes shall be subject to the exclusive jurisdiction of the courts of England and Wales.

9. Contact

ULSN Registry · Operated by PayPerArt Ltd · London, United Kingdom

Email: legal@ulsn.org

Privacy Policy

Last updated: 25 March 2026

What we collect

When you use the public verification service, we log the licence number queried, the timestamp, and your IP address. This data is used solely for rate limiting and abuse prevention.

When you submit an issuer application, we collect the information you provide (name, email, organisation details). This data is used to process your application and communicate with you about your issuer status.

How we use it

Verification logs are retained for 90 days and then deleted. Application data is retained for the duration of the issuer relationship plus 6 years as required by UK law.

Your rights

Under UK GDPR, you have the right to access, rectify, erase, restrict, and port your personal data. To exercise these rights, contact privacy@ulsn.org.

Data controller

PayPerArt Ltd · London, United Kingdom · ICO Registration: ZC064565