| C Thornton Limited | Construction | 2003 |
| C&N Investment Associates Limited | Financial services | 2024 |
| C&R Groundworks and Landscaping Limited | Construction | 2026 |
| C.A.H Hvac Services Ltd | Construction | 2013 |
| C.A.W. Engineering Solutions Limited | Professional & scientific | 2023 |
| C.Amey Plumbing & Heating Services Ltd | Construction | 2014 |
| C.Anderson Electrical Ltd | Construction | 2018 |
| C.Changes Coaching Ltd | Education | 2023 |
| C.J.B Builders Ltd | Construction | 2026 |
| C.P.T. Services Limited | Professional & scientific | 1999 |
| C6 + 71 UK Limited | Real estate | 2025 |
| Cabello Lounge Ltd | Other services | 2025 |
| Cade Group Limited | Financial services | 2015 |
| Cade Roofing & Building Services Limited | Construction | 1993 |
| Cadogan Place (Liphook) Ltd | Households | 2012 |
| Cadrel Limited | Information & communication | 2026 |
| Cafe at Zero 5 Ltd | Hospitality | 2020 |
| Caftrack App Ltd | Information & communication | 2026 |
| Cairnsly Limited | Information & communication | 2022 |
| Calafsharaf Ltd | Information & communication | 2026 |
| Calclo Limited | Transport & logistics | 2014 |
| Caledonian Woods & Camping Limited | Agriculture & fishing | 2025 |
| Cali Cartel Limited | Wholesale & retail | 2020 |
| Calian UK Ltd | Administrative & support | 2004 |
| Camber Holdings (South) Ltd | Real estate | 2026 |
| Cambridge Oncology Centre Limited | Health & social care | 2018 |
| Cambridge Wine Festival Limited | Hospitality | 2026 |
| Campbell & Long Legal Support Services Limited | Professional & scientific | 2013 |
| Campra UK Ltd | Hospitality | 2021 |
| Camsure Fire and Security Limited | Construction | 2021 |
| Cancer Research Pakistan | Health & social care | 2025 |
| Candice Tamara Coaching Ltd | Education | 2020 |
| Candor Contracting Ltd | Construction | 2025 |
| Candor Southern Ltd | Construction | 2025 |
| Canty Engineering Services Limited | Professional & scientific | 2024 |
| Cape Horn Engineering Limited | Professional & scientific | 2014 |
| Capital Arch Ltd | Financial services | 2025 |
| Capital Developments (Property) Limited | Construction | 2004 |
| Capital Softwood (Northern) Limited | Agriculture & fishing | 2008 |
| Capital Softwood (Southern) Limited | Agriculture & fishing | 2008 |
| Capital Softwood Ltd. | Agriculture & fishing | 1998 |
| Captivate Publishing Ltd | Information & communication | 2020 |
| Capz Technical Limited | Professional & scientific | 2017 |
| Car Buying Advisor Ltd | Other services | 2012 |
| Car Call (U.K.) Ltd | Other services | 2007 |
| Car Call Motor Claims Assistance Ltd | Transport & logistics | 2025 |
| Car Cosmetics (Hampshire) UK Limited | | 2009 |
| Carbon & NET Zero Consulting Ltd | Professional & scientific | 2025 |
| Carbon Filters Direct Ltd | Wholesale & retail | 2006 |
| Carboncube Motion Ltd | Information & communication | 2024 |
| Carcini Designs Limited | Professional & scientific | 2021 |
| Carcini Hill Farm Ltd | Agriculture & fishing | 2023 |
| Card PAY Accept Ltd | Financial services | 2019 |
| Careplanuk Limited | Health & social care | 2025 |
| Caricom Freight Forwarder Ltd | Transport & logistics | 2025 |
| Carl Mccaffrey Management Services Limited | Financial services | 2012 |
| Carl's Handyman Service Ltd | Extraterritorial | 2020 |
| Carlane Court Flat Management Company Limited | Households | 1991 |
| Carmelina Zerin Ltd | Manufacturing | 2023 |
| Carol Ashton Consulting & Coaching Ltd | Professional & scientific | 2018 |
| Carousel Amusements Limited | Arts & recreation | 2006 |
| Carousel Management Holdings (UK) Limited | Financial services | 2012 |
| Carp Junkie Ltd | Extraterritorial | 2024 |
| Carpets 2 Go (Portsmouth) Limited | Wholesale & retail | 2010 |
| Carray Computer Services Ltd | Other services | 2016 |
| Carriba Screenprint Limited | Manufacturing | 1994 |
| Carrieon Ltd | Health & social care | 2010 |
| Carrozzeria Lavanta Limited | Wholesale & retail | 2021 |
| Cartographix Ltd | Information & communication | 2015 |
| Carton Hydro Limited | Financial services | 2023 |
| Cartronix Cluster Repairs Limited | Manufacturing | 2016 |
| Carvendors Limited | Wholesale & retail | 2025 |
| Cash for Cars Hampshire Ltd | Wholesale & retail | 2019 |
| Cash Fuzion Limited | Professional & scientific | 2025 |
| Cash Handling Solutions Limited | Professional & scientific | 2016 |
| Cashflow Convos Limited | Professional & scientific | 2024 |
| Casn Corporation Limited | Manufacturing | 2023 |
| Caspian Construction Services Limited | Construction | 2012 |
| Castle Brickwork (Portsmouth) Ltd | Construction | 2016 |
| Castle Building & Restoration Limited | Construction | 2006 |
| Castle Business Services Ltd | Professional & scientific | 2021 |
| Castle Lodge Limited | Hospitality | 2016 |
| Castle Shines Limited | Administrative & support | 2022 |
| Castle Taxi Hire (West Sussex) Ltd | Transport & logistics | 2013 |
| Castlerigg Asset Management Limited | Real estate | 2002 |
| Catalyst Analytics Ltd | Professional & scientific | 2025 |
| Catalyst Commodities Ltd | Information & communication | 2014 |
| Cath Longhurst Consulting Ltd | Education | 2020 |
| Cathedral Fire Limited | Construction | 1998 |
| Catherington Country Pubs Ltd | Hospitality | 2020 |
| Catherington Nursery | Education | 2006 |
| Cathi Hadley Consultancy Limited | Professional & scientific | 2026 |
| Catology Feline Grooming Ltd | Other services | 2023 |
| Cats Holdings Ltd | Financial services | 2022 |
| Cats Scaffolding Ltd | Construction | 2018 |
| Cave Entertainment and Event Limited | Information & communication | 2025 |
| CAZ Rail Limited | Transport & logistics | 2013 |
| Cazz Ltd | Financial services | 2024 |
| Cbcf Holdings Limited | Financial services | 2023 |
| CBL Powerworx Ltd | Construction | 2023 |