| Calantha Ltd | Information & communication | 2026 |
| Caldera Protech Limited | Other services | 2012 |
| Caldiston Limited | Professional & scientific | 2008 |
| Caledonian Tyres Limited | Water & waste | 2006 |
| Calibr Talent Limited | Administrative & support | 2025 |
| Calibra Accountancy Ltd | Professional & scientific | 2023 |
| Calidad Construction Limited | Construction | 2015 |
| Callell Limited | Professional & scientific | 2012 |
| Calluna Medical Limited | Health & social care | 2018 |
| Calluna Wholesale Limited | Health & social care | 2015 |
| Calm Beverages Limited | Other services | 2019 |
| Cambridge Acumen Limited | Health & social care | 2019 |
| Camco Solutions Limited | Hospitality | 2001 |
| Cameron PMO Advisory Ltd | Professional & scientific | 2026 |
| Camnay Ltd | Information & communication | 2026 |
| CAN Lobo Limited | Professional & scientific | 2014 |
| Cancerlegalexperts Limited | Health & social care | 2018 |
| Cani Property Management Ltd | Real estate | 2026 |
| Cannavacciuolo Gennaro Ltd | Hospitality | 2022 |
| Cannon Cardiology Limited | Health & social care | 2025 |
| Canonbury Medical Ltd | Health & social care | 2016 |
| Canova Medical Limited | Health & social care | 2004 |
| Capital Foot and Ankle Limited | Health & social care | 2023 |
| Capital Life Funeral Planning Ltd | Other services | 1998 |
| Capital Life Group Limited | Other services | 2017 |
| Capital Life Independent Trustee Company Limited | Financial services | 2017 |
| Capital Raise Community Limited | Information & communication | 2025 |
| Capitaltec Recruitment Limited | Administrative & support | 2020 |
| Capstone Park Limited | Administrative & support | 2023 |
| Capstone Project Solutions Ltd | Professional & scientific | 2025 |
| Capture Vault Limited | Information & communication | 2026 |
| Caramel Holding Co. Ltd | Financial services | 2025 |
| Carbon Prestige Ltd | Wholesale & retail | 2021 |
| Carder Radiology Ltd | Health & social care | 2024 |
| Cardflo Limited | Administrative & support | 2021 |
| Cardiac Imaging Liverpool Ltd | Professional & scientific | 2012 |
| Cardinali Advisory Ltd | Professional & scientific | 2026 |
| Cardio-Oncology UK Ltd | Health & social care | 2022 |
| Cardiocare Limited | Health & social care | 2019 |
| Care and Repair Sevenoaks Ltd | Wholesale & retail | 2016 |
| Care Cube Solutions Ltd | Information & communication | 2015 |
| Care of the Skin Limited | Other services | 2016 |
| Care Plus Homecare Services Ltd | Health & social care | 2006 |
| Caree Limited | Administrative & support | 2023 |
| Careskills Academy Ltd | Administrative & support | 2013 |
| Cariad Ubaid Services Ltd | Information & communication | 2021 |
| Caritas Services Limited | Health & social care | 2006 |
| Carlton Holdings Limited | Professional & scientific | 1946 |
| Caroline Mills Limited | Health & social care | 2015 |
| Carpets and More Limited | Wholesale & retail | 2012 |
| Carrie & Co Ltd | Other services | 2014 |
| Cartel Holdings Limited | Real estate | 2016 |
| Casa DE Stock Ltd | Real estate | 2020 |
| Cast Interior Design Limited | Administrative & support | 2019 |
| Cast Iron Fireplace Restorations Ltd | Manufacturing | 2019 |
| Castle Fields (Ewloe Green) Management Company Limited | Households | 2014 |
| Castlefield Contracts Limited | Real estate | 1996 |
| Castletons Accountancy Limited | Professional & scientific | 2025 |
| Castletons Accountants Limited | Professional & scientific | 2010 |
| Castletons Trustee Ltd | Professional & scientific | 2025 |
| Castleview Surgical Limited | Health & social care | 2019 |
| Castleview Training Ltd | Education | 2014 |
| Castro Northrop Limited | Information & communication | 2018 |
| Casual Crush Clothing Ltd | Wholesale & retail | 2025 |
| Cat Nose Best Limited | Wholesale & retail | 2023 |
| Catam Limited | Financial services | 2018 |
| Catherine Boden Ltd | Other services | 2016 |
| Cato PMC Limited | Administrative & support | 2026 |
| Caulker Properties Ltd | Real estate | 2026 |
| Cautious MAN Limited | Professional & scientific | 2012 |
| CB Warehouse Consultancy Limited | Information & communication | 2010 |
| Cbcgi Limited | Information & communication | 2025 |
| CC (Taunton) Newco Limited | Professional & scientific | 2025 |
| CC (Telford) Newco Limited | Professional & scientific | 2024 |
| Cc&Ip Ltd | Professional & scientific | 2020 |
| CCL Yorkshire Limited | Information & communication | 2014 |
| Cctv Rentals Limited | Financial services | 2006 |
| CD Mechanical Ltd | Construction | 2017 |
| CDT Detailing Ltd | Wholesale & retail | 2020 |
| CDW Developments Limited | Construction | 2020 |
| Cecchi Media Limited | Professional & scientific | 2021 |
| Cecil Square (Stamford) Management Company Limited | Households | 2017 |
| Cedar Projects (NW) Limited | Construction | 2024 |
| Cedar Square Rentals Ltd | Households | 2025 |
| Celensia Limited | Wholesale & retail | 2010 |
| Cell:Cm (Saltire) Limited | Administrative & support | 2016 |
| Cell:Cm Ltd | Administrative & support | 2008 |
| Central Sight UK Limited | Health & social care | 2021 |
| Centre for Social Relations Ltd | Extraterritorial | 2014 |
| Centre Ltd | Extraterritorial | 2024 |
| Centreline Residential Limited | Construction | 2023 |
| Centreline Superior Homes Limited | Construction | 2023 |
| Certainty Ltd | Professional & scientific | 2026 |
| CF Cars Group Ltd | Wholesale & retail | 2025 |
| CF30 Consulting Limited | Administrative & support | 2019 |
| CG Counselling & Coaching Ltd | Health & social care | 2025 |
| CGW Aesthetics Ltd | Health & social care | 2016 |
| CH Tree Services & Landscaping Limited | Administrative & support | 2023 |
| Chafes Hague Lambert LLP | | 2008 |
| Chag UK Ltd | Information & communication | 2022 |