Clients of Chestnut Consultants Limited have included:
- Heatherwood & Wexham Park Foundation Trust
- South London Healthcare
- Lambeth Community Health
- Colchester Hospital Foundation Trust
- Royal Berkshire Foundation Trust
- Healthcare Commission
- Department of Health
- Royal Mail
- Barclays Bank & Barclays Wealth
- NatWest
- Royal Bank of Scotland
- BT
- One2One (T-Mobile)
- Ernst & Young
- CBI
- Britannia Building Society
- Hambro Assured
- FEB
- Serco Limited
- Andersen Consulting