| Container Projects Co Limited | Administrative & support | 2026 |
| Content Cravings Limited | Information & communication | 2019 |
| Content Productions Limited | Information & communication | 2000 |
| Continuum Energy Limited | Professional & scientific | 2026 |
| Controuk Limited | Information & communication | 2020 |
| Conuk Limited | Wholesale & retail | 2021 |
| Convert-Construction Ltd | Construction | 2003 |
| Coode Associates Ltd | Professional & scientific | 2009 |
| Cool Container Industries Limited | Administrative & support | 2024 |
| Cool Containers Limited | Administrative & support | 2024 |
| Cool Industries (UK) Limited | Wholesale & retail | 2023 |
| Cool Industries Limited | Wholesale & retail | 2018 |
| Cool Mate Ltd | Information & communication | 2025 |
| Cool Real Estate Limited | Real estate | 2018 |
| Cool Sea Containers Limited | Administrative & support | 2024 |
| Cooltrucks Limited | Transport & logistics | 2018 |
| Cooper Dawn Jerrom Limited | Professional & scientific | 2002 |
| Cooperative Capital Limited | Transport & logistics | 2024 |
| Coplow Limited | Administrative & support | 2017 |
| Coppergate Newbury Limited Partnership | | 2020 |
| Coppergate Northill Limited Partnership | | 2019 |
| Coppergate Ringmer Limited Partnership | | 2019 |
| Coppergate Sion Hill Place LP | | 2019 |
| Core 6 Solutions Ltd | Information & communication | 2012 |
| Core Chiro Ltd | Health & social care | 2025 |
| Corelli Global Ltd | Wholesale & retail | 2020 |
| Cork and Bottle Richmond Limited | Hospitality | 2022 |
| Corner House Property Investment Limited | Hospitality | 2021 |
| Cornerstone Tutors Ltd | Education | 2015 |
| Coromandel Consulting Limited | Professional & scientific | 2017 |
| Corporate Link | | 1984 |
| Corum Renovations Ltd | Construction | 2025 |
| Coruxa Limited | Real estate | 2025 |
| Coseer Limited | Professional & scientific | 2024 |
| Cosirius Limited | Professional & scientific | 2024 |
| Cosmic Apps Limited | Information & communication | 2013 |
| Cosmos Tours Limited | Administrative & support | 1974 |
| Cosmos Transport Services Limited | Administrative & support | 1995 |
| Cottonmill Trading Limited | Real estate | 2025 |
| Counselling and Psychotherapy Network Ltd | Health & social care | 2023 |
| Country Living Stoves Ltd | Construction | 2023 |
| Countryside Property Limited | Extraterritorial | 2020 |
| Countycare Windows & Property Services Ltd | Construction | 2016 |
| Courier Software Ltd | Transport & logistics | 2002 |
| Courtlands Avenue Partnership Ltd | Real estate | 1996 |
| Courtlands Holdings Limited | Households | 2020 |
| Courtprime Limited | Real estate | 1977 |
| Cove Eire Limited | Other services | 2006 |
| Covenant Applied Intelligence Advisory Limited | Professional & scientific | 2025 |
| Covesta Limited | Financial services | 2021 |
| Covil Services Ltd | Transport & logistics | 2018 |
| Coyote Holdings Limited | Real estate | 2015 |
| CP Bigwood Management LLP | | 2011 |
| CP Travel Consultancy Limited | Professional & scientific | 2003 |
| CPMW2 Limited | Real estate | 2025 |
| CR Global UK 1 Ltd | Real estate | 2021 |
| CR Global UK 2 Ltd | Real estate | 2021 |
| CR Global UK 3 Ltd | Real estate | 2023 |
| CR Global UK 4 Ltd | Real estate | 2024 |
| CR Global UK 5 Ltd | Real estate | 2025 |
| Crackpot Films Limited | Information & communication | 2010 |
| Craft Distilling Group Limited | Wholesale & retail | 2022 |
| Craid AI Limited | Information & communication | 2023 |
| Craig Gowland Limited | Agriculture & fishing | 2009 |
| Cranbourn Holdings Limited | Wholesale & retail | 2018 |
| Cranford Lodge Residents Limited | Households | 1976 |
| Cranleigh Court Freehold Limited | Households | 2026 |
| Crawdaddy Club Ltd | Arts & recreation | 2013 |
| Cream Magenta Consulting Limited | Administrative & support | 2021 |
| Created by US Ltd | Professional & scientific | 2021 |
| Creation Company (Films) Limited | Information & communication | 1986 |
| Creation Two Limited | Information & communication | 2001 |
| Creative Diam Limited | Wholesale & retail | 2025 |
| Creative Space Limited | Professional & scientific | 1980 |
| Creative Walks Limited | Administrative & support | 2020 |
| Credit Smart Ltd | Administrative & support | 2023 |
| Credonplus OOD Ltd | Real estate | 2017 |
| Creed Construction and Developments Ltd | Construction | 2024 |
| Crewe Management Ltd | Information & communication | 2019 |
| Criador Solutions Ltd | Information & communication | 2005 |
| Crimson Fish Limited | Professional & scientific | 2018 |
| Critical Path Solutions Limited | Information & communication | 2015 |
| Critical Power Installations Ltd | Construction | 2022 |
| Crjl Traffic Limited | Construction | 2024 |
| Crofts Creative Limited | Information & communication | 2013 |
| Crow Trees Bunkbarn Limited | Hospitality | 2024 |
| Crowdmna Limited | Administrative & support | 2018 |
| Crown & Butler Limited | Real estate | 2022 |
| Crown and Sceptre Streatham Ltd | Hospitality | 2019 |
| Crownvalley Properties Limited | Real estate | 2018 |
| CRS Asset Support Ltd | Professional & scientific | 2016 |
| Cruise Britain Limited | Other services | 2015 |
| Cruise Excursions Limited | Administrative & support | 2024 |
| Cruise Lines International Association UK & Ireland Limited | Other services | 1959 |
| Cruiseonline.Com UK Ltd | Administrative & support | 2023 |
| Cruse Bereavement Support | Health & social care | 1959 |
| Cruz Jorgensen Pilates Ltd | Other services | 2019 |
| Crystal Clear IC Limited | Information & communication | 2022 |
| Crystal Seating UK Limited | Manufacturing | 2025 |
| Csaep Limited | Real estate | 2026 |