By customer
- CompWest Insurance Company
- Comune di Messina
- Conad del Tirreno
- ConAgra Mills
- Concept One Accessories
- Concord Hospital
- Conforama
- Confused.com
- Connectria Corporation
- Consip
- Consolidated Edison Company of New York (Con Edison)
- Consolidated Edison of New York
- Consorzio Parmigiano-Reggiano
- Constantia Hueck Folien GmbH & Co. KG
- Constellation Software Engineering, Corp.
- Container Centralen
- CONTECH Contruction Products, Inc
- Continental Automotive
- Controlar S.A.
- ConvaTec
- Con-way Freight
- Coop Consorzio Nord Ovest (CCNO)
- Coop Estense
- Corenet Oy
- corma GmbH
- Corona Direct
- Covanta Energy
- Cranel Imaging
- Creativity Inc.
- Creditreform
- Credit Suisse Group
- CRH Europe Distribution
- Croatian Pensions Insurance Institute (HZMO)
- Crowley Maritime Corporation
- Crowley Maritime
- CSC Australia
- C Spire Wireless
- CSX Corporation
- CSX Transportation
- Cubist Pharmaceuticals, Inc.
- CustomInk
- CyberAgent
- Cyber Network
- Cypress-Fairbanks Independent School District
- Cyprus Ministry of Health
- Cyprus Telecommunications Authority
- Czarnowski Display Service, Inc.
