| Condor Design Limited | Professional & scientific | 2003 |
| Conduct 360 Limited | Information & communication | 2020 |
| Conform IW Ltd | Construction | 2012 |
| Conict Limited | Professional & scientific | 2009 |
| Connect Family Ltd | Education | 2025 |
| Connex Bookkeeping Limited | Professional & scientific | 2026 |
| Connexcel Limited | Education | 2011 |
| Connis Traffic Management Ltd | Construction | 2023 |
| Conserve Hygiene Ltd | Water & waste | 2016 |
| Constantine Design Ltd | Administrative & support | 2017 |
| Construction and Vehicle Finance Limited | Financial services | 2022 |
| Construction Claims Advisory Limited | Professional & scientific | 2019 |
| Construction Managers Ltd | Construction | 2012 |
| Constructive Law Limited | Professional & scientific | 2019 |
| Construkt RS Limited | Administrative & support | 2021 |
| Consult IB Ltd | Information & communication | 2016 |
| Consumables for Printing Ltd | Professional & scientific | 2021 |
| Conti Property Ltd | Real estate | 2023 |
| Continuum Gaming Ltd | Information & communication | 2023 |
| Contract Gophers Ltd | Information & communication | 2019 |
| Control and Robotic Solutions Limited | Information & communication | 2013 |
| Control System Design Ltd | Professional & scientific | 2020 |
| Converged Solutions UK Limited | Extraterritorial | 2021 |
| Cooney Scientific Ltd | Professional & scientific | 2022 |
| Cooper Motion Limited | Information & communication | 2025 |
| Coopers Grange (School Lane) Management Limited | Households | 2014 |
| Copaproduct Limited | Wholesale & retail | 2015 |
| Cordier Management Limited | Administrative & support | 2019 |
| Core Fit 365 Limited | Other services | 2018 |
| Core Healthcare Support Ltd | Health & social care | 2022 |
| Corinne Williams Aesthetics Ltd | Other services | 2021 |
| Corner Shop Pizzeria Ltd | Wholesale & retail | 2024 |
| Cornerstone Heating & Plumbing Ltd | Construction | 2018 |
| Cornucopial Logistics UK Ltd | Transport & logistics | 2022 |
| Corporate Blue Consulting Limited | Administrative & support | 2020 |
| Corporate Needs Limited | Wholesale & retail | 2011 |
| Corpus Ltd | Information & communication | 2022 |
| Cortex Consultancy Ltd | Education | 2017 |
| Corvus Research Limited | Information & communication | 2022 |
| Cosmopolitan Global Brands Group Limited | Wholesale & retail | 2016 |
| Cost and Construction Management Limited | Construction | 1991 |
| Costs Track Limited | Professional & scientific | 2006 |
| Country Caregivers Limited | Health & social care | 2014 |
| County Locksmiths (Chandlers Ford) Limited | Wholesale & retail | 2000 |
| Courage Trading Ltd | Financial services | 2023 |
| Couriers & More Ltd | Transport & logistics | 2022 |
| Courtyard Equestrian Limited | Agriculture & fishing | 2017 |
| Courtyard Luxury & Performance Ltd | Wholesale & retail | 2018 |
| Covichy Limited | Health & social care | 2023 |
| Coza Care Limited | Public administration | 2025 |
| Cozyeats Limited | Hospitality | 2025 |
| CPR Music Publishing Ltd | Information & communication | 2005 |
| CPR Music Services Ltd | Professional & scientific | 2016 |
| Cprt Investments Ltd | Real estate | 2025 |
| CPS Engineering Services Ltd | Professional & scientific | 2024 |
| CPS RF Limited | Manufacturing | 2026 |
| CR Ceilings Limited | Construction | 2009 |
| Craftpoint Advisory Limited | Professional & scientific | 2026 |
| Craig Morton Services Limited | Professional & scientific | 2024 |
| Crakan Ltd | Professional & scientific | 2019 |
| Cranberry Limited | Financial services | 2025 |
| Cranberry Wellbeing Centre Limited | Real estate | 2023 |
| Cranbourne Homes (UK) Limited | Real estate | 2006 |
| Crane Machine Maintenance Limited | Manufacturing | 1989 |
| Cranefamily Home Improvements Limited | Other services | 2025 |
| Cranlea Holdings Limited | Real estate | 1987 |
| Craven Installations Ltd | Construction | 2014 |
| CRE4M Ltd | Construction | 2026 |
| Creative Catalyst Innovation Limited | Information & communication | 2023 |
| Creative Colours International Ltd | Wholesale & retail | 2008 |
| Creative Concepts Global Limited | Manufacturing | 2025 |
| Creative Lending Solutions Ltd | Financial services | 2022 |
| Credence Systems (UK) Limited | Wholesale & retail | 1989 |
| Crescent Control Systems Ltd | Professional & scientific | 2024 |
| Crescent Ground Rents Limited | Real estate | 2023 |
| Crest Civil Engineering Limited | Wholesale & retail | 1997 |
| Crest Comfort Cooling & Ventilation Ltd | Construction | 2020 |
| Crest Consult Ltd | Professional & scientific | 2026 |
| Crewing, Yachting & Groups (Cyg-Net) Limited | Administrative & support | 2000 |
| Crewseekers Limited | Arts & recreation | 2000 |
| CRI8VE Nest International Business Ltd | Hospitality | 2024 |
| Cricketers Limited | Hospitality | 2016 |
| Crime Reduction Intelligence Management Services Ltd | Professional & scientific | 2023 |
| Crimson Pearl Ltd | Real estate | 2025 |
| Critical Insight Security Ltd | Information & communication | 2013 |
| CRK Design Limited | Manufacturing | 2002 |
| Croft Homes and Land Limited | Real estate | 2026 |
| Crosby & Oliver Properties Limited | Real estate | 2025 |
| Crosley-Hall Partnership Limited | Wholesale & retail | 2005 |
| Crossways Lymington Management Limited | Households | 2024 |
| Crown Competitions (Southern) Ltd | Other services | 2025 |
| Crown Medical Associates Ltd | Health & social care | 2023 |
| Crownswell Accountants Ltd | Professional & scientific | 2025 |
| Cruise Catering Ltd | Hospitality | 2015 |
| Cruise in Limited | Administrative & support | 2003 |
| Crvb Investments Limited | Real estate | 2025 |
| Crystal Clear Ventures Ltd | Administrative & support | 2012 |
| Crystal Management Recruitment Ltd | Administrative & support | 2018 |
| Crystal Spray Boat Charters Limited | Transport & logistics | 2017 |
| Crystal Spring Consumer Division Limited | Wholesale & retail | 1993 |