| Clean OUR Patch CIC | Professional & scientific | 2019 |
| Clean Slate SW Ltd | Water & waste | 2025 |
| Clean View Cleaning Services Ltd | Administrative & support | 2025 |
| Cleandust Ltd | Water & waste | 2019 |
| Cleanessencelocal Ltd | Administrative & support | 2025 |
| Cleanopolis Consult Limited | Real estate | 2021 |
| Cleanse-Oil Limited | Manufacturing | 2015 |
| Cleanspares (Plymouth) Limited | Wholesale & retail | 1982 |
| Clear Blue Sky Accountancy Ltd | Professional & scientific | 2016 |
| Clear Blue Sky Admin Ltd | Administrative & support | 2025 |
| Clear Blue Sky Payroll Bureau Ltd | Professional & scientific | 2022 |
| Clear CUT Design Solutions Limited | Professional & scientific | 2018 |
| Clear Market Intelligence Limited | Professional & scientific | 1997 |
| Clear Thinking Care Limited | Health & social care | 2014 |
| Clearance Outlet Limited | Wholesale & retail | 2016 |
| Clearjunk SW Ltd | Extraterritorial | 2020 |
| Clement Healthcare Limited | Health & social care | 2025 |
| Clever Estate Agents Limited | Real estate | 2024 |
| Clever Portfolio Ltd | Professional & scientific | 2025 |
| Clever Stay Limited | Real estate | 2019 |
| Clever Student Lets Limited | Real estate | 2010 |
| Click 4 Filters Ltd | Wholesale & retail | 2017 |
| Clickathon Limited | Wholesale & retail | 2017 |
| Cliff Bennett SCR Limited | Professional & scientific | 2016 |
| Clifford's Family Funeral Directors Limited | Other services | 2019 |
| Clifton Court Amenity Limited | Households | 2001 |
| Clifton Growth Consulting Limited | Administrative & support | 2021 |
| Climate Controls and Spares UK Ltd | Wholesale & retail | 2009 |
| Climatic Properties Management Limited | Households | 2017 |
| Climb Dartmoor Ltd | Other services | 2022 |
| Clinical Assurance Solutions Ltd | Information & communication | 2026 |
| Clinical Negligence Services Limited | Professional & scientific | 2000 |
| Clinicare Medical Solutions Limited | Health & social care | 2015 |
| Clinpark QA Ltd. | Professional & scientific | 2015 |
| Clipfeed Ltd | Information & communication | 2018 |
| Clipper Lettings Ltd | Real estate | 2017 |
| Clipper Property Holdings Ltd | Real estate | 2020 |
| Clittaford Limited | Real estate | 2023 |
| Clive Property Development Limited | Real estate | 2021 |
| Clockwork Audio Systems Limited | Wholesale & retail | 2006 |
| Cloud 9 Bakery LLP | | 2025 |
| Cloudbreak Surf Limited | Wholesale & retail | 2013 |
| Clouds Vape Ltd | Wholesale & retail | 2025 |
| Cloudsleigh Lodge RTM Company Limited | Households | 2007 |
| Cloudsource Solutions Limited | Professional & scientific | 2014 |
| Clovelly Bay Management Limited | Households | 1997 |
| CLR Heating and Plumbing Services SW Limited | Construction | 2026 |
| CLR Heating Limited | Construction | 2021 |
| CLS Office Limited | Wholesale & retail | 2017 |
| Club BAD Limited | Arts & recreation | 2018 |
| Clubnet Digital Ltd | Information & communication | 2016 |
| Clutch Care Centre Limited | Wholesale & retail | 2003 |
| CLV Transport Ltd | Transport & logistics | 2023 |
| CM Afro Hair Training Centre Community Interest Company | Education | 2025 |
| CM Associates SW Ltd | Professional & scientific | 2024 |
| CM Crane Services Ltd | Wholesale & retail | 2015 |
| CMB Mortgage Consultants Limited | Financial services | 2006 |
| CMC Electrical (SW) Ltd | Construction | 2024 |
| CMN Carpentry and Building Ltd | Construction | 2017 |
| Cmostores Holdings Limited | Financial services | 2020 |
| CMP Technologies Ltd | Professional & scientific | 2018 |
| CMS Accountancy Limited | Professional & scientific | 2024 |
| CMS Design Engineering Ltd | Extraterritorial | 2021 |
| CMS Geoscience Limited | Professional & scientific | 2013 |
| CMS Offshore Ltd | Professional & scientific | 2021 |
| CMS Property Developments Ltd | Real estate | 2016 |
| CMS Seven Limited | Professional & scientific | 2019 |
| Cmsgroup SW Ltd | Financial services | 2026 |
| CMW Property Services Limited | Real estate | 2014 |
| CNC Systems Limited | Manufacturing | 2000 |
| Cnvey Ltd | Information & communication | 2016 |
| Cnvr Limited | Manufacturing | 2002 |
| CNW1 Limited | Wholesale & retail | 2019 |
| Co&Co Property Solutions Ltd | Real estate | 2021 |
| Coach House Mews (Lewisham) Limited | Real estate | 2001 |
| Coach Special Contents World Ltd | Information & communication | 2025 |
| Coaction Training CIC | Education | 2022 |
| Coast & Country Flooring and Rugs Ltd | Wholesale & retail | 2023 |
| Coast & Quay Ltd | Hospitality | 2025 |
| Coast and Moor Properties Ltd | Real estate | 2026 |
| Coast Financial Limited | Financial services | 2017 |
| Coast Investments (South West) Ltd | Construction | 2014 |
| Coastal Card Vault Ltd | Wholesale & retail | 2026 |
| Coastal Drift Ltd | Information & communication | 2025 |
| Coastal Homecare Services Ltd | Health & social care | 2021 |
| Coastal Laundry Services Limited | Other services | 2023 |
| Coastal Property Developments Limited | Professional & scientific | 2006 |
| Coastal Strength CIC | Education | 2025 |
| Coastel Communications Limited | Administrative & support | 2018 |
| Coastline Contract Services Limited | Administrative & support | 2006 |
| Coastline Marine Services (Environmental) Ltd | Professional & scientific | 2022 |
| Coastline Marine Services Limited | Professional & scientific | 1991 |
| Coating Solutions (SW) Ltd | Manufacturing | 2020 |
| Cobblestone Creations Ltd | Hospitality | 2012 |
| Cochrane Gastro Limited | Health & social care | 2016 |
| Cockles Farm (Developments) Limited | Real estate | 2024 |
| Cockles Farm Limited | Real estate | 2024 |
| Codality Limited | Information & communication | 2016 |
| Code and Commerce Limited | Information & communication | 2023 |
| Codea Digital Ltd | Information & communication | 2018 |