Partner, Patent Attorney


James has over 15 years of experience in drafting and prosecuting patent applications at the EPO and UKIPO in a wide variety of technical fields, and has developed specialist knowledge in obtaining patent protection for information and communication technologies, with a particular focus on software and smart technologies.

James has experience in creating and managing large portfolios of patent applications for his clients, and of bringing these portfolios through to grant. He is passionate about ensuring that his clients get access to patent attorneys equipped with the requisite technical knowledge to handle their work, and is astute at seamlessly managing teams of attorneys within Mewburn to ensure his clients get access to patent attorneys with the skills they need.

James has always been interested in quickly developing and cutting edge technological fields, and is keen to work with clients who have the same passion he has for pushing the boundaries of what is possible.

Areas of Expertise

  • Computer software
  • Artificial intelligence
  • Communication technologies
  • Medtech
  • Mass spectrometry
  • Audio equipment
  • Imaging technologies


James works with multinational corporations, SMEs, start-ups and universities across the UK, Europe, USA and Japan. James does a lot of work with US attorneys to obtain patent protection for their clients in Europe. He is experienced at managing large portfolios of cases for his clients, at all stages of the patent application process.


James has a physics degree (MPhys) from the University of Oxford (First Class Honours). He joined Mewburn Ellis LLP in 2005, qualifying as a Chartered Patent Attorney and European Patent Attorney in 2009. He joined the partnership in 2013.


“I have worked with numerous European Patent attorneys over my career, and James Leach stands out as among the best. James is thorough, incredibly knowledgeable, and, most importantly, highly effective. I cannot recommend James more.”  Justin R Nifong, NK Patent Law PLLC

“I have worked with James for many years. His efforts have helped obtain many valuable IP assets in the EPO for our clients. His technical and legal analyses are reliably thorough and his feedback prompt.”  Cory G. Claassen, Christensen O’Connor Johnson Kindness PLLC