| Clarkes of Stillington Plate & Profiles Limited | Wholesale & retail | 1999 |
| Clarus Protect Limited | Wholesale & retail | 2023 |
| Classic Alton Ltd | Other services | 2024 |
| Classic Car Brokerage Ltd | Wholesale & retail | 2011 |
| Classic Car Restoration and Sales Ltd | Wholesale & retail | 2011 |
| Claudia Farming Holdings Limited | Agriculture & fishing | 2005 |
| Claudia Langmead Farming Limited | Agriculture & fishing | 2005 |
| Clear Dog Training Limited | Professional & scientific | 2025 |
| Clearnav UK Limited | Wholesale & retail | 2016 |
| Clementines Fruit & VEG Limited | Wholesale & retail | 2023 |
| Clifford Dean Limited | Professional & scientific | 2010 |
| Clinical and Healthcare Solutions Limited | Professional & scientific | 2022 |
| Clive Pheasants Ltd | Agriculture & fishing | 2015 |
| Clockwork City Limited | Administrative & support | 2015 |
| CMC Electrical Engineering Ltd | Construction | 2019 |
| CMS Property Investments Limited | Real estate | 2012 |
| Coaching Visions Ltd. | Professional & scientific | 2010 |
| Cobbetts Management Company Ltd | Households | 2021 |
| Cochoa Travel Limited | Administrative & support | 2020 |
| Codebreaker Ltd | Information & communication | 2017 |
| Coffee Cherry Limited | Wholesale & retail | 2016 |
| Collect London Ltd | Wholesale & retail | 2025 |
| Collins M&A Limited | Professional & scientific | 2012 |
| Colvincare Limited | Health & social care | 2013 |
| Commercial Sales & Services Limited | Wholesale & retail | 2021 |
| Commixt Limited | Information & communication | 2016 |
| Compact Powertrain Limited | Professional & scientific | 2018 |
| Compleet Limited | Health & social care | 2011 |
| Complete Drain Care Ltd | Other services | 2019 |
| Complete Floors Ltd. | Wholesale & retail | 2006 |
| Compsoft (UK) Ltd | Information & communication | 2001 |
| Comv Developments Ltd | Real estate | 2014 |
| Concept LED Lights Ltd | Manufacturing | 2012 |
| Concept Polo Ltd | Arts & recreation | 2023 |
| Concinnity Properties Limited | Real estate | 2022 |
| Concinnity Ventures Ltd | Health & social care | 2022 |
| Confiance Limited | Professional & scientific | 2020 |
| Congress Music Limited | Wholesale & retail | 2021 |
| Connect 4 Life | Administrative & support | 2010 |
| Conquip Engineering Group Company | Professional & scientific | 2006 |
| Conquip Engineering Group Holding Company Limited | Financial services | 2024 |
| Conquip Engineering Group Limited | Manufacturing | 2003 |
| Considered Design Limited | Professional & scientific | 1999 |
| Considering Canines Limited | Other services | 2020 |
| Consigno Limited | Professional & scientific | 2021 |
| Consilium Solutions Limited | Professional & scientific | 2014 |
| Constructek Ltd | Construction | 2018 |
| Content Copywriters Ltd | Professional & scientific | 2014 |
| Contract Mortgage Solutions Limited | Financial services | 2016 |
| Coombs Property Consultancy Limited | Professional & scientific | 2025 |
| Coopers Court (Hindhead) Ltd | Real estate | 2018 |
| Corax Partners Ltd | Professional & scientific | 2019 |
| Cornish Talent Partners Limited | Administrative & support | 2026 |
| Coronita Ltd | Hospitality | 2009 |
| Corporama Ltd | Administrative & support | 2005 |
| Cortole Limited | Real estate | 2002 |
| Cosmo Court Limited | Financial services | 2019 |
| Costra Limited | Professional & scientific | 2025 |
| Cotswold Close Residents Management Company Limited | Households | 2016 |
| Counselling & Therapy Directories Ltd | Administrative & support | 2024 |
| Country Mile Consulting Limited | Administrative & support | 2015 |
| Countryside Contracts Limited | Construction | 2007 |
| Court Estate (Crondall) Limited | Households | 1963 |
| Covent Garden (T) Hairdressing Limited | Other services | 2020 |
| Coxbridge Management Limited | Real estate | 2003 |
| Cozmo Home Ltd | Wholesale & retail | 2021 |
| Cranford Controls Limited | Manufacturing | 1995 |
| Cranteq Ltd | Administrative & support | 2019 |
| Create Design Studio Limited | Information & communication | 1989 |
| Creating Crafts and Blooms CIC | Wholesale & retail | 2022 |
| Cricketers Holdings Ltd | Financial services | 2025 |
| Critical Technical Services Group Limited | Public administration | 2025 |
| Cromwell Housing Limited | Administrative & support | 2025 |
| Cromwell Seymour Ltd | Professional & scientific | 2026 |
| Crooked Meadow Limited | Agriculture & fishing | 2011 |
| Crookham Motor Co. Limited | Wholesale & retail | 1958 |
| Crouch END (T2) Hairdressing Limited | Other services | 2024 |
| Crown Wood Management Limited | Households | 2010 |
| Croydon (T) Hairdressing Limited | Other services | 2012 |
| CSK Hire and Film Supplies Ltd | Wholesale & retail | 2025 |
| Csports Media Ltd | Professional & scientific | 2023 |
| CT Recruitment Services Ltd | Other services | 2020 |
| Cuddeford Properties Limited | Real estate | 2022 |
| Cullompton SYC V LLP | | 2012 |
| Cultural Capital London Limited | Financial services | 2022 |
| Curran Beer House Limited | Hospitality | 2023 |
| Currie Developments Limited | Construction | 2014 |
| Curry Daily Ltd | Hospitality | 2024 |
| Curtis Dream LLP | | 2017 |
| Curtis Ridge Associates Ltd | Professional & scientific | 2022 |
| CUT Feature Film Ltd | Information & communication | 2021 |
| CWS Investments Ltd | Real estate | 2026 |
| D & F Properties (Hitchin) Ltd | Real estate | 2003 |
| D & G Moulding Ltd. | Manufacturing | 1999 |
| D and C Freight Solutions Ltd | Transport & logistics | 2014 |
| D B Curtains Limited | Manufacturing | 2005 |
| D L Cross Construction Ltd | Construction | 2018 |
| D M a Autos Ltd | Wholesale & retail | 2002 |
| D&Lbeauty Ltd | Other services | 2024 |
| D.P.Hall Group Ltd | Information & communication | 2026 |