| Crystal Shine Hand Car Wash Ltd | Wholesale & retail | 2026 |
| Crystalcare Limited | Public administration | 2018 |
| Crystalgates Technical & Facility Services Limited | Administrative & support | 2017 |
| CS Complete Building Services Ltd | Construction | 2021 |
| CS Electronics (UK) Limited | Information & communication | 2009 |
| CS Fruit and VEG Limited | Wholesale & retail | 2025 |
| CS Gaming Ltd | Information & communication | 2026 |
| CS Gardens & Landscaping Ltd | Other services | 2025 |
| CS Services (Midlands) Ltd | Construction | 2013 |
| CS45 Ltd | Wholesale & retail | 2023 |
| CSA Safety Solutions Ltd | Professional & scientific | 2020 |
| Csabaf Limited | Other services | 2025 |
| Csaw Solutions Limited | Professional & scientific | 2013 |
| CSB UK Investments Limited | Real estate | 2023 |
| CSE Projects Limited | Construction | 2014 |
| CSG Distribution Ltd | Transport & logistics | 2023 |
| CSI Joinery Ltd | Construction | 2018 |
| Cskotai Limited | Construction | 2025 |
| CSM Leicester Ltd | Other services | 2014 |
| Cspa Rana Limited | Information & communication | 2024 |
| CSR Management Limited | Professional & scientific | 2014 |
| CSR Solutions Ltd | Administrative & support | 2025 |
| Cssv Property Holdings Limited | Real estate | 2026 |
| CST Foods Ltd | Manufacturing | 2026 |
| CT & Co UK Limited | Wholesale & retail | 2025 |
| CT Alarms Limited | Administrative & support | 2018 |
| CT Appliance Repairs Limited | Other services | 2014 |
| CT Enterprises Ltd | Professional & scientific | 2023 |
| CT Lufbra Ltd | Other services | 2025 |
| CT4N Charitable Trust | Transport & logistics | 1988 |
| CTA Graphics Limited | Manufacturing | 2011 |
| Ctcs-Care Limited | Administrative & support | 2024 |
| Ctcs-Holdings Limited | Financial services | 2025 |
| CTD Hendon Ltd | Health & social care | 2016 |
| Ctex NTX Limited | Administrative & support | 2006 |
| Ctex Software Ltd | Professional & scientific | 2012 |
| CTF Group Limited | Financial services | 2022 |
| CTH Hendon Ltd | Health & social care | 2016 |
| Ctig Auto Spares Ltd | Wholesale & retail | 2021 |
| CTJ Property Management Ltd | Real estate | 2025 |
| CTL & SON Building Services Ltd | Construction | 2024 |
| CTP Solutions (UK) Ltd | Manufacturing | 2009 |
| CTS Leicester Ltd | Wholesale & retail | 2025 |
| Ctwc Ltd | Professional & scientific | 2025 |
| Cuban Properties Ltd | Real estate | 2024 |
| Cubari Properties Ltd | Real estate | 2025 |
| Cube 123 Bidco Limited | Financial services | 2025 |
| Cube 123 Midco Limited | Financial services | 2025 |
| Cube 123 Topco Limited | Financial services | 2025 |
| Cube Core Consultants Limited | Professional & scientific | 2023 |
| Cube Network Ltd | Information & communication | 2016 |
| Cube Retail Displays Ltd | Manufacturing | 2018 |
| Cube Retail Holdings Ltd | Financial services | 2023 |
| Cube Rooms Limited | Real estate | 2017 |
| Cube Vodka Ltd | Wholesale & retail | 2022 |
| Cubic Property Ltd | Real estate | 2024 |
| Cubitrose Limited | Transport & logistics | 1982 |
| Cubmar Ltd | Transport & logistics | 2014 |
| Cubra Investment Properties Ltd | Real estate | 2023 |
| Cubs Consultants Limited | Real estate | 1994 |
| Cuddly Care Ltd | Wholesale & retail | 2022 |
| CUE Bistro Ltd | Hospitality | 2024 |
| CUE Property Ltd | Real estate | 2017 |
| CUE Sports Ltd | Administrative & support | 2016 |
| Cuffling Transport Service Ltd | Transport & logistics | 2024 |
| Cuisine of India Limited | Hospitality | 2007 |
| Cuisine World Limited | Hospitality | 2017 |
| Cuknuk UK Limited | Wholesale & retail | 2025 |
| Cullen Cars Limited | Wholesale & retail | 2025 |
| Cullen Wealth Holdings Limited | Financial services | 2020 |
| Cullen Wealth Limited | Financial services | 1998 |
| Culmen Holdings Limited | Professional & scientific | 2017 |
| Culsom (U.K.) Limited | Real estate | 1984 |
| Cult Creamery Ltd | Hospitality | 2024 |
| Culver Shades Ltd | Wholesale & retail | 2022 |
| Cumberhills Farm (Duffield) Management Company Limited | Households | 2006 |
| Cunningtons Probate Limited | Professional & scientific | 2022 |
| CUP and Bean Ltd | Hospitality | 2017 |
| CUP DMU Ltd | Hospitality | 2024 |
| CUP Factory Group Ltd | Financial services | 2022 |
| CUP Factory Limited | Hospitality | 2021 |
| CUP of Care Ltd | Health & social care | 2025 |
| Cupcake Delights Ltd. | Manufacturing | 2017 |
| Cupi Properties LLP | | 2023 |
| Cuppa Cafe Ltd | Hospitality | 2026 |
| Cura Domestica Care Limited | Health & social care | 2026 |
| Curalene Ltd | Manufacturing | 2021 |
| Curantis Health Ltd | Health & social care | 2022 |
| Curated Events Ltd | Arts & recreation | 2025 |
| Curavo Cleaning Limited | Administrative & support | 2025 |
| Curbside Cravings Ltd | Hospitality | 2026 |
| Curbu Ltd | Information & communication | 2021 |
| Cure Consultants Limited | Health & social care | 2026 |
| Cured Health Ltd | Wholesale & retail | 2024 |
| Curefy Group Ltd | Wholesale & retail | 2025 |
| Curl JAR Ltd | Wholesale & retail | 2021 |
| Curldrop Ltd | Wholesale & retail | 2024 |
| Curly Mango Gifts Limited | Wholesale & retail | 2018 |
| Currant Affairs Ltd | Hospitality | 2026 |
| Currie Freight Limited | Transport & logistics | 2026 |