Bill has the following accreditations and memberships as a mediator:
- Distinguished Fellow of the International Academy of Mediators (International)
- Certified Mediator, International Mediation Institute (International)
- Member of Civil Mediation Council, UK
- ICC Mediator (Paris and international)
- CPR International Mediator, New York, USA
- International Mediator Panel, Singapore Mediation Centre Mediator, Singapore
- Singapore International Mediation Institute, Certified Mediator, Singapore
- CEDR Accredited Mediator, London, UK
- MATA Advanced Mediator Accreditation, London, UK
- Solicitor and Member, Law Society of England and Wales