Patent Infringement Demand Letter Template for England and Wales

A Patent Infringement Demand Letter is your first line of defence when someone is unlawfully using your patented invention. Under England and Wales law, this formal notice serves as a crucial step in the enforcement process, demonstrating your serious intent to protect your intellectual property rights whilst providing the alleged infringer an opportunity to resolve the matter without court intervention.

When do you need this document?

You need this letter when you discover that another party is manufacturing, selling, or using your patented invention without permission. This could involve competitors copying your product design, manufacturers producing unauthorised versions, or businesses using your patented process. The letter is essential before filing a patent infringement claim in the High Court, as the Pre-action Protocol for Intellectual Property Claims requires you to send formal notice and attempt resolution before litigation. You may also need this document when licensing negotiations have failed, when you've discovered infringement through market research, or when preparing to seek interim injunctions to stop ongoing violations.

Key legal considerations

Your letter must include specific elements to be legally effective under the Patents Act 1977. You need to identify your patent clearly with the patent number, filing date, and invention title. The infringement description must be detailed and specific, explaining exactly how the recipient's actions constitute direct or indirect infringement under sections 60-69 of the Patents Act. Include evidence such as product specifications, photographs, or technical analyses that demonstrate the infringement. Your demands must be reasonable and proportionate, typically requesting cessation of infringement, delivery up of infringing goods, and damages or account of profits. Be aware that section 62 of the Patents Act restricts damages recovery in certain circumstances, particularly if the infringer was unaware of the patent. Consider whether to mark your products with patent numbers, as this affects your ability to claim damages for past infringement.

Legal requirements in England and Wales

The letter must comply with the Pre-action Protocol for Intellectual Property Claims, which requires sufficient detail to enable the recipient to understand and investigate the allegations. You must provide reasonable time for response, typically 21-28 days for straightforward cases. Under the Civil Procedure Rules Part 63, your correspondence should facilitate early resolution and avoid unnecessary litigation costs. The Intellectual Property (Enforcement, etc.) Regulations 2006 provide additional framework for enforcement measures. Ensure your letter is proportionate to avoid potential adverse costs orders if litigation follows. Consider whether alternative dispute resolution might be appropriate, as courts expect parties to explore settlement options. Document all correspondence carefully, as it may be relevant in subsequent proceedings and could affect costs awards under CPR rules.