Ability Associates and Dennis Trevarthen have provided services to a range of clients, both large and small, private and public sector. The following list samples some of these:

• BP Australia (getfreight.com Chief Information Officer)
• Telstra Australia (specialist VOIP technical training)
• BHP Billiton MINEX (Minerals Exploration)
• Telecommunications and Information Technology Training Board
• Swinburne University
• Iluka Mining
• CSL Group Ltd
• iShop Port Douglas (eCommerce design)
• Salty Dog Blues N Roots Podcast (podcast, streaming audio, marketing)
• Dimension Data Australia
• NH Architecture
• NH Webb Interior Design
• Athena Interiors
• Coral Sea Limousines
• The DAT Corporation Pty Ltd (Chief Executive and Principal Consultant)
• AMP Society
• ANTA (Australian National Training Authority)
• ACMA (Australian Communications and Media Authority)
• APEC (Asia Pacific Ecomonic Forum)
• Building and Construction National Industry Training Board
• Local Government National Industry Training Board
• Brambles Ltd
• Austmart
• KAZ Technology
• VTAC
• Department of Justice - Victoria
• NZI Insurance Ltd
• Macquarie Textiles
• AUSDOC Australia
• Insurance Training Australia
• National Mining Industry Training Board
• National Small Business Standards Australia
• National Recreation Industry Training Board
• Property Services Training Australia
• South Australian Engineering and Water
• St. Helena Massage Therapy
• Aquaforce Surface Restoration