| Clyde Road RTM Company Limited | Households | 2010 |
| Clydex Estates Ltd | Real estate | 2010 |
| Clym Studio Limited | Arts & recreation | 2014 |
| CM Care Limited | Health & social care | 2007 |
| CM Safety Training Limited | Professional & scientific | 2016 |
| CME Demolition Ltd | Construction | 2025 |
| Cmeasy Limited | Professional & scientific | 2007 |
| CMI Couriers Ltd | Transport & logistics | 2024 |
| CMK Properties Holding Ltd | Real estate | 2022 |
| CMM & Sons Holding Limited | Financial services | 2025 |
| CMT Developments Ltd | Households | 2013 |
| CN Pharma Ltd | Professional & scientific | 2019 |
| Cnaimhin Limited | Administrative & support | 2023 |
| CNW Courier Network UK Ltd. | Transport & logistics | 2022 |
| Coachworks Lodge Management Company Limited | Households | 2010 |
| Coalpeak Limited | Professional & scientific | 2016 |
| Coastline Productions Ltd | Arts & recreation | 2005 |
| Cobham House Vineyard Ltd | Agriculture & fishing | 2023 |
| Cochani Limited | Wholesale & retail | 2024 |
| Cochani London Ltd | Wholesale & retail | 2024 |
| Coco 29 Ltd | Hospitality | 2024 |
| Coco General Building Ltd | Construction | 2026 |
| Coco Greens (PVT) Limited | Hospitality | 2026 |
| Coco London Ltd | Hospitality | 2020 |
| Cocoa Blush Limited | Real estate | 2007 |
| Cocoon Capsule Limited | Administrative & support | 2017 |
| Cocoon Lifestyle Ltd | Hospitality | 2019 |
| Code One Media Limited | Information & communication | 2010 |
| Coderama Limited | Professional & scientific | 2021 |
| Codermates Ltd | Information & communication | 2022 |
| Codlogz Technologies Limited | Wholesale & retail | 2024 |
| Cody Gardener Ltd | Water & waste | 2025 |
| Cofetaria Bianca Ltd | Wholesale & retail | 2016 |
| Cogent Accountants Ltd | Professional & scientific | 2015 |
| Cognira Analytics Ltd | Information & communication | 2026 |
| Coker Cares Ltd | Health & social care | 2023 |
| Colchester Building Supplies Ltd | Construction | 2013 |
| Coldpoint Services Ltd | Construction | 2001 |
| Coldroomuk.Com Ltd | Hospitality | 2019 |
| Colesnic Ltd | Construction | 2024 |
| Colin Imperium Limited | Professional & scientific | 2026 |
| Colin Investments Ltd | Real estate | 2025 |
| Colindale Coffee Limited | Hospitality | 2026 |
| Colindale Gardens (NO.1) Residents Company Limited | Households | 1987 |
| Collective Organics Limited | Hospitality | 2016 |
| Collector Base Ltd | Wholesale & retail | 2025 |
| College Catering Company Limited | Hospitality | 1987 |
| College Market Ltd | Wholesale & retail | 2021 |
| Colletts Investments Limited | Real estate | 2017 |
| Collignon Consultancy Ltd | Professional & scientific | 2018 |
| Collins Brothers Limited | Wholesale & retail | 1944 |
| Colmer 1 Ltd | Construction | 2020 |
| Colmer 2 Limited | Real estate | 2022 |
| Colmer Group Ltd | Real estate | 2020 |
| Colroy Trading Limited | Wholesale & retail | 2012 |
| Columbia Court Residents Association Limited | Households | 1984 |
| Coly Construction Ltd | Construction | 2019 |
| Comera Academy Limited | Education | 2023 |
| Cometville Limited | Health & social care | 1990 |
| Comfaura Ltd | Wholesale & retail | 2025 |
| Comfort Station Limited | Wholesale & retail | 2002 |
| Comfortable Dwellings Limited | Hospitality | 2023 |
| Commanche Consultancy Ltd | Information & communication | 2024 |
| Commerce Tech Ltd. | Information & communication | 2012 |
| Commercial Loans Ltd | Extraterritorial | 2016 |
| Committee Miss Angola UK Community Interest Company | Education | 2025 |
| Comodon Johnson Limited | Real estate | 2022 |
| Comp Holdings Limited | Financial services | 2019 |
| Compact Building Ltd | Construction | 2020 |
| Companies DOT Support Ltd | Professional & scientific | 2021 |
| Compass Close RTM Company Ltd | Households | 2020 |
| Compass Construction & Maintenance Services Ltd | Construction | 2016 |
| Compass Professional Consortium UK Ltd | Real estate | 2013 |
| Compass Property 001 Ltd | Real estate | 2021 |
| Compass Supplies Limited | Hospitality | 2019 |
| Competitive Pro Gaming Ltd | Professional & scientific | 2024 |
| Compfinesse Limited | Professional & scientific | 2023 |
| Complete Care (UK) Limited | Health & social care | 2003 |
| Complete Construction Solutions Limited | Construction | 2010 |
| Compton Christie Limited | Professional & scientific | 2021 |
| Comtech Logic Ltd | Wholesale & retail | 2006 |
| Comyn Properties Limited | Construction | 1958 |
| Conbertex Limited | Administrative & support | 2012 |
| Concept One Design Limited | Wholesale & retail | 2017 |
| Concept Square Limited | Information & communication | 2022 |
| Conceptual Solution Ltd | Wholesale & retail | 2022 |
| Concilio Investments Limited | Real estate | 2016 |
| Concorde Advisory Limited | Professional & scientific | 2021 |
| Concordia PIM (Investments) Limited | Real estate | 2019 |
| Cone Holdings Limited | Financial services | 2021 |
| Conexxion Limited | Construction | 2017 |
| Confident Healthcare Limited | Wholesale & retail | 2012 |
| Confident Investments Limited | Real estate | 2024 |
| Congologistics Ltd | Transport & logistics | 2021 |
| Coniscliffe Commercial Services Limited | Professional & scientific | 2017 |
| Conker Nation Plant Limited | Construction | 2016 |
| Conker Nation Scaffolding Services Ltd | Construction | 2025 |
| Connaught Catering Ltd | Hospitality | 2015 |
| Connect Bangladesh International Ltd | Health & social care | 2025 |
| Connect Homes and Developments Ltd | Real estate | 2015 |