| Coast and Country Lighting Limited | Wholesale & retail | 2025 |
| COAST2COAST Pipeline Services Limited | Construction | 2023 |
| Coastal Energy Limited | Energy | 2017 |
| Coastal Fitness (Devon) Limited | Arts & recreation | 2022 |
| Coastal Healthcare Consulting Limited | Health & social care | 2023 |
| Coastal Joinery Ltd | Manufacturing | 2021 |
| Coastal Oaks Psychology Services Ltd | Education | 2024 |
| Coastal Recycling Holdings Limited | Professional & scientific | 2020 |
| Coastal Recycling Services Limited | Water & waste | 2011 |
| Coastal Recycling Trustees Limited | Administrative & support | 2021 |
| Coastal UK Group Limited | Water & waste | 2006 |
| Coastal UK Resources Ltd | Administrative & support | 2014 |
| Coastal Waste Recycling Limited | Water & waste | 2007 |
| Coastmoor Associates Limited | Administrative & support | 2020 |
| Cobalt Communication Solutions Limited | Information & communication | 2009 |
| Cobalt Computer Solutions Limited | Information & communication | 2002 |
| Cobalt Developments SW Limited | Construction | 2025 |
| Coban Brothers Ltd | Transport & logistics | 2020 |
| Cobb House Limited | Real estate | 1927 |
| Cobham Road Solar Farm Limited | Energy | 2023 |
| Cobwebs South West Limited | Administrative & support | 2001 |
| Coco Brothers Developments Ltd | Construction | 2021 |
| Coco Harding Limited | Real estate | 2020 |
| Cocofrutas Limited | Agriculture & fishing | 2021 |
| Coconut Energy Ltd | Construction | 2022 |
| Codance Ltd | Information & communication | 2026 |
| Code Cabin Ltd | Information & communication | 2013 |
| Code Guardians Software Development Ltd | Information & communication | 2024 |
| Code Leaf Limited | Information & communication | 2018 |
| Code Reading Club Community Interest Company | Education | 2022 |
| Codefactory Software Limited | Information & communication | 2013 |
| Codefirst Ltd | Information & communication | 2013 |
| Codepreflight Limited | Information & communication | 2026 |
| Cody & Partners Limited Partnership | | 2011 |
| Coffee Heaven Ltd | Hospitality | 2022 |
| Cofton Road Car Centre Ltd. | Transport & logistics | 2000 |
| Cognitiva Psychological Services Limited | Health & social care | 2015 |
| COH16 Limited | Financial services | 2017 |
| Coho Whipton Village Road Ltd | Real estate | 2025 |
| Cojo Confectionery Limited | Wholesale & retail | 2018 |
| Colab Exeter Ltd. | Health & social care | 2003 |
| Coldforms Jewellery Ltd | Manufacturing | 2024 |
| Coleman Management Solutions Ltd | Professional & scientific | 2026 |
| Coles Crescent Manco Limited | Households | 2021 |
| Colico Consult Ltd | Real estate | 2025 |
| Colico Living (Bristol) Limited | Real estate | 2020 |
| Colico Living (Cardiff) Limited | Real estate | 2021 |
| Colico Living Limited | Real estate | 2020 |
| Colkin Trustee Company Limited | Administrative & support | 1998 |
| Collaborative Planning Limited | Professional & scientific | 2024 |
| Collars and Tails Limited | Agriculture & fishing | 2025 |
| College Music Records Ltd | Information & communication | 2018 |
| Colleton Crescent Gardens Management Company Limited | Other services | 2015 |
| Colmer Ecology Ltd | Professional & scientific | 2011 |
| Colony Shops Ltd | Wholesale & retail | 2017 |
| Colorado Property Ltd | Real estate | 2024 |
| Colston Property Ltd | Real estate | 2026 |
| Columbjohn Farm Limited | Agriculture & fishing | 2002 |
| Colville Hartley & Parsons Financial Services Ltd. | Financial services | 2011 |
| Comae Limited | Health & social care | 1993 |
| Combat Championship Wrestling Ltd | Arts & recreation | 2023 |
| Combined Networks Limited | Information & communication | 2023 |
| Comerford Consulting Limited | Professional & scientific | 2014 |
| Comic Strip Limited | Information & communication | 2019 |
| Commerceon Ltd | Wholesale & retail | 2016 |
| Commercial Estates Property Company Limited | Real estate | 1985 |
| Commercial Vehicles (Yeovil) Limited | Financial services | 2012 |
| Commins Consultancy Ltd | Administrative & support | 2021 |
| Committee for Academic Freedom CIC | Education | 2023 |
| Common Seas C.I.C. | Professional & scientific | 2013 |
| Commongood Exeter Ltd | Information & communication | 2025 |
| Community Care Services Limited | Extraterritorial | 1992 |
| Community Care Trust (South West) Limited | Health & social care | 1989 |
| Community Council of Devon | Health & social care | 1999 |
| Community Equality Disability Action | Health & social care | 2003 |
| Community Interest Solar Projects CIC | Construction | 2025 |
| Company Film Solutions Ltd | Information & communication | 2013 |
| Compare Carbon Limited | Wholesale & retail | 2022 |
| Compass Resolution Ltd | Professional & scientific | 2011 |
| Complete Aircraft Group Limited | Financial services | 2020 |
| Complete Aircraft Holdings Limited | Financial services | 2022 |
| Complete Aircraft Leasing Limited | Extraterritorial | 2020 |
| Complete Aircraft Parts Limited | Wholesale & retail | 2020 |
| Complete Aircraft Purchases Limited | Extraterritorial | 2020 |
| Complete Aircraft Recycling Limited | Extraterritorial | 2020 |
| Complete Aircraft Tooling Limited | Transport & logistics | 2019 |
| Complete Build Partnerships Ltd | Construction | 2022 |
| Complete Builders Merchants Limited | Wholesale & retail | 2017 |
| Complete Cleaning Services (South West) Limited | Administrative & support | 1988 |
| Complete Currency Trader Ltd | Information & communication | 2012 |
| Complete Engine Services Limited | Manufacturing | 2022 |
| Complete Group South West Limited | Real estate | 2018 |
| Complete Project Management (Exeter) Limited | Construction | 2015 |
| Complete Solutions South Limited | Construction | 2025 |
| Complete Solutions SW Ltd | Construction | 2022 |
| Complete Water Solutions Limited | Construction | 2009 |
| Complycover Ltd | Information & communication | 2023 |
| Composite Panel Consultants Ltd | Administrative & support | 2024 |
| Compton Commercials Ltd | Extraterritorial | 2014 |
| Computer Components Limited | Information & communication | 1997 |