| Clear Funding Solutions Ltd | Financial services | 2016 |
| Clear Insight Works Limited | Education | 2025 |
| Clear Pace Consulting Ltd | Information & communication | 2015 |
| Clear Smiles Ltd | Health & social care | 2022 |
| Clear Therapy Ltd | Health & social care | 2014 |
| Clearandfizzy Limited | Administrative & support | 2012 |
| Clearcall AI Ltd | Information & communication | 2025 |
| Cleardebt Group Limited | Financial services | 2015 |
| Cleardebt Limited | Financial services | 2004 |
| Cleared Risk Limited | Professional & scientific | 2023 |
| Clearissue Limited | Hospitality | 1997 |
| Clearoute Consulting Limited | Professional & scientific | 2025 |
| Clearpath Business Solutions Ltd | Professional & scientific | 2025 |
| Clearstep Recruitment Limited | Administrative & support | 2025 |
| Clearswift Holding Limited | Information & communication | 2011 |
| Clearswift Limited | Information & communication | 1997 |
| Clearswift Technologies Holdings Limited | Information & communication | 1998 |
| Clearview CBT Limited | Health & social care | 2013 |
| Clementine Limited | Professional & scientific | 2018 |
| Cleopatra Multitrades Limited | Other services | 2019 |
| Click Once Limited | Information & communication | 2011 |
| Click Right Communications Limited | Administrative & support | 2008 |
| Clickhouse UK Co. Ltd. | Information & communication | 2023 |
| Clinton Consultants Limited | Administrative & support | 2008 |
| Clipzoom Limited | Information & communication | 2024 |
| Clive Griffiths Associates Limited | Administrative & support | 2010 |
| CLJ Productions Ltd | Professional & scientific | 2022 |
| CLK Design Limited | Professional & scientific | 2017 |
| Cloaked Privacy Ltd | Information & communication | 2025 |
| Clocktower Creative Limited | Information & communication | 1998 |
| Clonmar Estates Ltd | Real estate | 2022 |
| Cloud 21 Software Solutions Limited | Information & communication | 2019 |
| Cloud Digital Services Limited | Information & communication | 2021 |
| Cloud Guardians Limited | Professional & scientific | 2022 |
| Cloud Marquis Consultant Ltd | Wholesale & retail | 2023 |
| Cloud Rocker IT Limited | Information & communication | 2022 |
| Cloud Tech Specialists Limited | Professional & scientific | 2021 |
| Cloud Vault IT Solutions Limited | Information & communication | 2024 |
| Cloudaeon Technologies Limited | Administrative & support | 2016 |
| Cloudbase Services Limited | Information & communication | 2022 |
| Cloudensity Limited | Professional & scientific | 2017 |
| Cloudm Holdco Limited | Financial services | 2025 |
| Cloudm Software Limited | Information & communication | 2021 |
| Cloudmedic Ltd | Professional & scientific | 2020 |
| Cloudnomic Limited | Professional & scientific | 2025 |
| Cloudskate Limited | Professional & scientific | 2021 |
| Cloudtower Ltd | Information & communication | 2026 |
| Cloudv Limited | Information & communication | 2022 |
| Cloudy Glaciers Ltd | Wholesale & retail | 2026 |
| Clough Springs Management Company Limited | Households | 2003 |
| Clove Group Limited | Information & communication | 2025 |
| Clove Wealth Limited | Information & communication | 2026 |
| Clovelly Management Company Limited | Households | 1984 |
| Clover Private Limited | Transport & logistics | 2026 |
| Cloverley (Sale) Limited | Households | 1982 |
| Cloverley House Management Company Limited | Households | 1985 |
| CLS Energy Contracts Consulting Limited | Professional & scientific | 2023 |
| Club Olympus Trustees Limited | Other services | 2009 |
| Club Studio Ltd | Arts & recreation | 2013 |
| Clustersoft Consulting Ltd | Information & communication | 2019 |
| Clutch IT Limited | Professional & scientific | 2019 |
| CLW Composites Limited | Professional & scientific | 2026 |
| CM Care Consultancy Ltd | Professional & scientific | 2019 |
| CM Holiday Lettings Limited | Real estate | 2020 |
| CM Joinery & Building Services Limited | Construction | 2006 |
| CM Procurement Group Limited | Administrative & support | 2022 |
| CM Short Stories & Health Ltd | Health & social care | 2017 |
| Cmac Consultancy Limited | Professional & scientific | 2022 |
| Cmas Rents Subsid Limited | Real estate | 2022 |
| CMC Contract Management Solutions Limited | Professional & scientific | 2022 |
| CMC Ravenna UK Limited | Extraterritorial | 2018 |
| Cmdty UK Ltd. | Information & communication | 2019 |
| CMR Relocation Limited | Administrative & support | 2011 |
| Cmrenovationspecialist Limited | Real estate | 2025 |
| CMT Tools (UK) Limited | Wholesale & retail | 1995 |
| Cmtb Investments Limited | Real estate | 2021 |
| CMW Consulting Limited | Professional & scientific | 2025 |
| CMW Productions Ltd | Information & communication | 2006 |
| Cnbt UK Limited | Construction | 2014 |
| CNC GH Ltd | Financial services | 2025 |
| Cnen Ltd | Wholesale & retail | 2022 |
| CNW853 Digital Learning Consultancy Limited | Administrative & support | 2022 |
| Co Valere Consulting Limited | Professional & scientific | 2022 |
| Coach Houses Management Company Limited | Professional & scientific | 2006 |
| Coachdoc Limited | Health & social care | 2010 |
| Coaching Crumble Ltd | Professional & scientific | 2026 |
| Coaching Sports Ltd | Education | 2023 |
| Coalesce Dance CIC | Arts & recreation | 2026 |
| Coalesce Dance Theatre Ltd | Arts & recreation | 2018 |
| Coast & Country Cottages (Holdings) Limited | Extraterritorial | 2013 |
| Coast & Country Cottages (South West) Ltd | Extraterritorial | 2000 |
| Coast & Country Holidays Ltd | Extraterritorial | 2008 |
| Coastal and Country Developments Limited | Construction | 2010 |
| Coastal and Country Retreats Limited | Hospitality | 2020 |
| Coastal Homes (North Wales) Limited | Construction | 2013 |
| Cobble Hill Clothing Ltd | Wholesale & retail | 2024 |
| Cobco (236) Limited | Real estate | 1998 |
| Cobo Bay Limited | Real estate | 2020 |
| Cocoa Properties Ltd. | Real estate | 2004 |
| Cocoa’S PUP Club Ltd | Other services | 2025 |