| Business Integration Services Ltd | Professional & scientific | 2015 |
| Busy Bees @ ST Lawrence Alton Ltd | Education | 2019 |
| Buxton Heating Ltd | Other services | 2009 |
| Byways Travel Limited | Administrative & support | 1996 |
| C & E Vine Labours Ltd. | Agriculture & fishing | 2016 |
| C&G Bikes LLP | | 2020 |
| C&V Limited | Public administration | 2018 |
| C.C.E. Projects Limited | Construction | 1987 |
| C.H.Munday Limited | Wholesale & retail | 1918 |
| Cait Demetriadi Ltd | Administrative & support | 2023 |
| Camber Garage Doors Limited | Construction | 2011 |
| Camberhall Estates Ltd | Construction | 2003 |
| Canty Treasury Management Limited | Professional & scientific | 2001 |
| Capital Focus Ltd | Real estate | 2023 |
| Caravan Service and Repairs Ltd | Manufacturing | 2021 |
| Carboot Guru Ltd | Extraterritorial | 2024 |
| Card Journeys Limited | Wholesale & retail | 2025 |
| Careangels (PVT) Limited | Health & social care | 2014 |
| Carnaby Homes Ltd | Professional & scientific | 2019 |
| Caroline Hirst Ltd | Real estate | 2020 |
| Carpet Care Direct Limited | Other services | 2016 |
| Carpet Connection (Worsley) Limited | Wholesale & retail | 2003 |
| Carron Marquees Ltd | Other services | 1999 |
| Carruthers Window Cleaning Ltd | Administrative & support | 2017 |
| Carrychem Ltd | Administrative & support | 2012 |
| Castaldi Illuminazione (UK) Limited | Extraterritorial | 2003 |
| Cavill Consulting Limited | Information & communication | 2002 |
| CC Venues Limited | Hospitality | 2012 |
| CDM Consulting (UK) Ltd | Professional & scientific | 2012 |
| Cedar Breaks Limited | Professional & scientific | 1994 |
| Celab Power Management Limited | Professional & scientific | 1990 |
| Celestial Event Management Limited | Hospitality | 2024 |
| Centeno Limited | Arts & recreation | 2014 |
| Centora Electrical Contractors Ltd | Construction | 2023 |
| Centrex Software Limited | Extraterritorial | 1992 |
| Ceratech Accuratus Limited | Manufacturing | 2014 |
| Champs Driving School Ltd | Wholesale & retail | 2019 |
| Channellite Ltd | Information & communication | 2024 |
| Charles Sirrell & SON Ltd | Wholesale & retail | 2003 |
| Chexperts Ltd | Administrative & support | 2024 |
| Chief Operations Ltd | Wholesale & retail | 2020 |
| Christian Faversham Limited | Hospitality | 2014 |
| Churchill Accounting Limited | Professional & scientific | 2023 |
| Citizens Advice East Hampshire Limited | Information & communication | 2008 |
| Civils South Coast Limited | Construction | 2021 |
| Classic Car Mechanic Limited | Wholesale & retail | 2020 |
| Classical Ceramics Limited | Construction | 2004 |
| Clayhill Futures Ltd | Real estate | 2003 |
| Clean My Space Services Ltd | Administrative & support | 2025 |
| Clear Brew Portsmouth Ltd | Administrative & support | 2021 |
| Clear Bridge Mediation Ltd | Administrative & support | 2026 |
| Clear Mind Counselling Limited | Extraterritorial | 2021 |
| Clear PMO Consulting Ltd | Professional & scientific | 2025 |
| Clifford Farm (Management) Limited | Administrative & support | 2003 |
| Clinical Training Services Limited | Health & social care | 2015 |
| Club Nimbus Ltd | Health & social care | 2025 |
| CM Assure Limited | Information & communication | 2017 |
| CMK Trading Limited | Wholesale & retail | 2016 |
| Coalition Groundworks Ltd | Construction | 2024 |
| Cobar Nursing Limited | Administrative & support | 2019 |
| Coldroom Solution Ltd | Energy | 2024 |
| Colts (Southern) Limited | Construction | 2002 |
| Colts Property Ltd | Construction | 2021 |
| Communications Network Limited | Information & communication | 1998 |
| Competitive Electrical Services Limited | Construction | 2020 |
| Complete Merchandise Limited | Wholesale & retail | 2010 |
| Concept Build Group Ltd | Construction | 2020 |
| Concept Land & Assets Ltd | Construction | 2020 |
| Concrete Repair Association | Other services | 1995 |
| Conet Ltd | Wholesale & retail | 2016 |
| Confelicity Music Limited | Information & communication | 2017 |
| Confelicity Records Limited | Information & communication | 2017 |
| Conker Accountancy Limited | Professional & scientific | 2015 |
| Conker Financial Services Limited | Financial services | 1994 |
| Conker Limited | Financial services | 2003 |
| Content Merchants Limited | Professional & scientific | 2020 |
| Control C Ltd | Information & communication | 2022 |
| Cool Training Limited | Wholesale & retail | 2008 |
| Coomers Group Holdings Limited | Financial services | 2020 |
| Coomers Limited | Wholesale & retail | 1978 |
| Corbey Consulting Limited | Administrative & support | 2022 |
| Correia Holdings Ltd | Financial services | 2025 |
| Corrosion Prevention Association | Other services | 1996 |
| Corylus Collective Ltd | Health & social care | 2020 |
| Counterpoint Coffee Ltd | Manufacturing | 2024 |
| Counting Properties Limited | Information & communication | 2015 |
| County Equine Ltd | Professional & scientific | 2014 |
| Courts Chauffeur Cars (Alton) Ltd | Transport & logistics | 2022 |
| Cowgirl Design Limited | Professional & scientific | 2025 |
| CR Eco Energy Limited | Construction | 2025 |
| Creaser’S IT Support Limited | Extraterritorial | 2024 |
| Created by Miranda Ltd | Professional & scientific | 2024 |
| Creative Form Limited | Education | 2017 |
| Credor Point Ltd | Professional & scientific | 2003 |
| Credor Point Services Ltd | Professional & scientific | 2024 |
| Croxley Holdings Limited | Manufacturing | 2024 |
| Cumulo Aerospace Ltd | Administrative & support | 2026 |
| Curtain Galleria Limited | Manufacturing | 2012 |
| Custom Puddle Lights Ltd | Wholesale & retail | 2025 |
| Customs Cloud Ltd | Information & communication | 2020 |