| CJB Property Holdings Ltd | Real estate | 2021 |
| CJR Advisory Limited | Professional & scientific | 2023 |
| Ckph Limited | Hospitality | 2020 |
| CKS Kitchens Limited | | 2003 |
| Claire Lawton Physiotherapy Limited | Other services | 2024 |
| Clambertine (Management) Limited | Financial services | 2012 |
| Clambertine Limited | Construction | 2012 |
| Classic Car Prototype & Development Ltd | Wholesale & retail | 2021 |
| Classic Cotswold Pubs Ltd | Hospitality | 2022 |
| Claviga Limited | Professional & scientific | 1997 |
| Clayfurlong Barns Management Co. Limited | Households | 2007 |
| Clayfurlong View Management Company Limited | Households | 2021 |
| Clear Look Limited | Wholesale & retail | 2019 |
| Clearcatch Ltd | Information & communication | 2025 |
| Clearwater Asset Holdings Ltd | Construction | 2017 |
| Clearwater Customs Limited | Wholesale & retail | 2015 |
| Clearwater Pro Trading Ltd | Construction | 2021 |
| Clifton Psychiatry Ltd | Health & social care | 2022 |
| CMJ Carpentry Limited | Construction | 2025 |
| Coalition Ltd | Professional & scientific | 2023 |
| Cobtaw Limited | Wholesale & retail | 2017 |
| Cocometa Limited | Wholesale & retail | 2023 |
| Codex Software Solutions Ltd | Information & communication | 2015 |
| Codima Inc (Europe) Ltd | Information & communication | 2008 |
| Coffee at ODD Socks Ltd | Hospitality | 2019 |
| COG Security Limited | Information & communication | 2016 |
| Cognifit AI Limited | Information & communication | 2026 |
| Colenso Ventures Limited | Manufacturing | 2018 |
| Colethrop Farm Limited | Agriculture & fishing | 1997 |
| Collaborative Care Group Limited | Health & social care | 2026 |
| Collapse-Proof Ltd | Information & communication | 2026 |
| Collector Limited(The) | Information & communication | 1955 |
| Collier Banks Limited | Professional & scientific | 2009 |
| Collier Bristow Ltd | Wholesale & retail | 2013 |
| Collingwood Potter Estates Ltd | Real estate | 2024 |
| Collingwood Potter Ltd | Wholesale & retail | 2020 |
| Colmar Limited | Wholesale & retail | 1985 |
| Coln Capital Ltd | Hospitality | 2023 |
| Coln Manor Management Company Limited | Households | 1987 |
| Coln Mill LLP | | 2021 |
| Coln Valley Cabs Limited | Transport & logistics | 2003 |
| Colncaple Limited | Real estate | 2014 |
| Colnside Construction Limited | Construction | 2000 |
| Colnside Developments Limited | Construction | 2024 |
| Combat Splat Limited | Arts & recreation | 2008 |
| Commatic Limited | Information & communication | 1998 |
| Commsevolution Ltd | Transport & logistics | 2011 |
| Communid Limited | Professional & scientific | 2022 |
| Complete Asset Solutions (UK) Limited | Wholesale & retail | 2025 |
| Complete Machinery Limited | Wholesale & retail | 2017 |
| Complete Risk Management Commodities Limited | Administrative & support | 2014 |
| Complete Wealth Solutions Ltd | Financial services | 2009 |
| Compost Ltd | Education | 2021 |
| Computer & Audio Ltd | Information & communication | 2015 |
| Computer Conquest Limited | Information & communication | 2004 |
| Connect Electrical Limited | Construction | 2022 |
| Connexus IT Solutions Ltd | Wholesale & retail | 2016 |
| Consider Care Limited | Health & social care | 2018 |
| Constance Design Ltd | Professional & scientific | 2024 |
| CONSTRUCT300 Ltd | Construction | 2022 |
| Contemporary Art Holdings Limited | Wholesale & retail | 2000 |
| Continental Soil Technology Limited | Wholesale & retail | 2006 |
| Control System Support Ltd | Professional & scientific | 2018 |
| Controlsoft Limited | Manufacturing | 2002 |
| Cool Lockers UK Limited | Wholesale & retail | 2016 |
| Coomanore Consulting Ltd | Professional & scientific | 2021 |
| Core to Cloud Ltd | Information & communication | 2015 |
| Core to Cloud Services Limited | Information & communication | 2025 |
| Corin AUS Finco Limited | Financial services | 2018 |
| Corin Bidco Limited | Financial services | 2018 |
| Corin Finco Limited | Financial services | 2018 |
| Corin Holdco Limited | Financial services | 2018 |
| Corin Limited | Manufacturing | 1985 |
| Corin Midco Limited | Financial services | 2018 |
| Corin Orthopaedics Holdings Limited | Manufacturing | 2012 |
| Corin US Finco Limited | Financial services | 2018 |
| Corinium Accountancy Services Limited | Professional & scientific | 2020 |
| Corinium Aerospace Design Limited | Professional & scientific | 2013 |
| Corinium Ales Ltd | Manufacturing | 2012 |
| Corinium Assets Limited | Real estate | 2026 |
| Corinium Capital Advisory Ltd | Financial services | 2026 |
| Corinium Capital Limited | Financial services | 2025 |
| Corinium Cleaning Services Ltd | Administrative & support | 2024 |
| Corinium Consulting Ltd | Information & communication | 2015 |
| Corinium Court Limited | Real estate | 2000 |
| Corinium Driveways & Patios Limited | Construction | 2021 |
| Corinium Education Trust | Education | 2011 |
| Corinium Electronics Limited | Wholesale & retail | 2021 |
| Corinium Enterprises Ltd | Hospitality | 2016 |
| Corinium Investigative Solutions Ltd | Administrative & support | 2011 |
| Corinium IT Limited | Information & communication | 2022 |
| Corinium Livery Ltd | Arts & recreation | 2011 |
| Corinium Maritime Consultants Limited | Other services | 2019 |
| Corinium Paints Limited | Wholesale & retail | 2013 |
| Corinium Payments Ltd | Information & communication | 2025 |
| Corinium Plastering Ltd | Construction | 2023 |
| Corinium Plumbing and Heating Ltd | Construction | 2017 |
| Corinium Property Maintenance Limited | Construction | 2016 |
| Corinium Property Sales Limited | Real estate | 2025 |
| Corinium Renovations Ltd | Real estate | 2024 |