Warren is a past co-ordinator to the APIL spinal cord injury special interest group (a post held for more than a decade).
He is an APIL fellow and member of (and assessor for) the APIL spinal cord injury and APIL brain injury expert panels. He is also the Chief Assessor for the Law Society personal injury accreditation panel.
He is a partner at Penningtons Manches Cooper LLP in London, where he handles a broad range of complex serious injury and fatal accident claims. He has concluded numerous spinal cord injury, brain injury and amputee claims.
Warren undertakes a significant amount of international work and is the founding member and inaugural chair of the spinal cord injury Litigation Group to AAJ (the American Association for Justice – formerly the Association of Trial Lawyers of America). He is on the Board of Governors for AAJ.
He is also the only UK solicitor member of the Melvin Belli Society (pre-eminent personal injury lawyers of America) and the National Crime Victims Bar Association (of America) and the National Trial Lawyers Top 100 (USA).
Warren is listed as a leading individual in Legal 500 and Chambers UK. He lectures extensively on his areas of expertise. He has won multiple awards for his work, including the UKABIF award for Inspiration in Acquired Brain Injury as well as the Eclipse Proclaim Claimant Injury Lawyer of the Year (2013) the Spinal Injuries Association Award for Legal Excellence (2015) and Catastrophic Injury Lawyer of the Year (2018).
He is trustee of Brain Injury is BIG, a national charity supporting the loved ones of those with minimal awareness or disorders of consciousness.