| CMS Trading Ltd | Wholesale & retail | 2018 |
| Cmsg 001 Ltd | Administrative & support | 2022 |
| Cmsg 002 Ltd | Administrative & support | 2022 |
| Cmsg 003 Ltd | Administrative & support | 2021 |
| Cmsg 008 Ltd | Public administration | 2020 |
| Cmsg 013 Ltd | Administrative & support | 2023 |
| Cmsg 014 Ltd | Administrative & support | 2023 |
| Cmsg 015 Ltd | Administrative & support | 2018 |
| Cmsg 016 Ltd | Other services | 2019 |
| Cmsg 017 Ltd | Public administration | 2020 |
| Cmsg 022 Ltd | Administrative & support | 2021 |
| Cmsg 023 Ltd | Administrative & support | 2020 |
| Cmsg 025 Ltd | Other services | 2019 |
| Cmsg 026 Ltd | Administrative & support | 2022 |
| Cmss Group Ltd | Financial services | 2022 |
| CMV Services Ltd | Wholesale & retail | 2021 |
| CMW Painting Services Ltd | Construction | 2021 |
| CMW Property Investments Ltd | Real estate | 2023 |
| CMW Property Trading Ltd | Real estate | 2023 |
| CNA Resources Limited | Financial services | 2013 |
| Cnark Ltd | Professional & scientific | 2024 |
| CNB Portobello Limited | Other services | 2012 |
| CNB Property Development Limited | Real estate | 2022 |
| CNC Cardiff Ltd | Construction | 2021 |
| CNC Plus Ltd | Wholesale & retail | 2014 |
| Cndpay Ltd | Information & communication | 2025 |
| Cnext Ltd | Information & communication | 2020 |
| Cnnglobal Ltd | Wholesale & retail | 2024 |
| Cnpaf UK CIC | Health & social care | 2023 |
| Cnpr Limited | Construction | 2016 |
| CNS Global Ltd | Wholesale & retail | 2025 |
| Cnsr Ltd | Extraterritorial | 2020 |
| CNT Etkinlik Yonetimi Ltd | Administrative & support | 2025 |
| Co-Fx Technology Limited | Financial services | 2020 |
| Co-Home Living CYF | Real estate | 2020 |
| Co-Hydrover Developments Ltd | Manufacturing | 2015 |
| CO2N Media Ltd | Arts & recreation | 2025 |
| Coach and Grow Limited | Professional & scientific | 2022 |
| Coach Enterprises Limited | Real estate | 2016 |
| Coach Hire Limited | Transport & logistics | 2015 |
| Coach House Corner Ltd | Households | 2018 |
| Coach House Farm Limited | Agriculture & fishing | 2012 |
| Coach House Living Ltd | Real estate | 2025 |
| Coach ME Tech Limited | Professional & scientific | 2012 |
| Coach-House Property Limited | Real estate | 2021 |
| Coach-House Sales and Lettings Ltd | Real estate | 2010 |
| Coaches AI Ltd | Information & communication | 2025 |
| Coaching in Motion Ltd | Professional & scientific | 2022 |
| Coaching the Thinking Way Ltd | Administrative & support | 2019 |
| Coachme Limited | Information & communication | 2025 |
| Coachmyhealth Ltd | Health & social care | 2020 |
| Coachsync Ltd | Education | 2025 |
| Coagulance Limited | Wholesale & retail | 2025 |
| Coal and Brick Limited | Real estate | 2015 |
| Coals and Waste Management Ltd | Mining & quarrying | 2025 |
| Coast & Code Ltd | Administrative & support | 2020 |
| Coast Hair Ltd | Other services | 2016 |
| Coast Yachts Ltd | Other services | 2016 |
| Coastal Boats Limited | Manufacturing | 2021 |
| Coastal Construction Essex Ltd | Manufacturing | 2025 |
| Coastal Extensions Ltd | Construction | 2022 |
| Coastal Smiles Limited | Health & social care | 2021 |
| Coastside Limited | Health & social care | 2007 |
| Coat Health Care Ltd | Health & social care | 2022 |
| Coated Metal Trading Limited | Manufacturing | 2017 |
| Coates (Holdings) Limited | Real estate | 1948 |
| Cobalt Enterprises (UK) Ltd | Construction | 2015 |
| Cobalt HR Limited | Administrative & support | 2016 |
| Cobalt Signature Ltd | Administrative & support | 2025 |
| Cobalt Sports Management Limited | Professional & scientific | 2019 |
| Cobaltrise Ltd | Wholesale & retail | 2025 |
| Cobaltvista Limited | Wholesale & retail | 2025 |
| Cobbina Marketing Consulting Ltd | Professional & scientific | 2019 |
| Cobella Beauty & Aesthetics Ltd | Other services | 2023 |
| Cobenmia Ltd | Construction | 2017 |
| Cobham CC Ltd | Transport & logistics | 2011 |
| Cobra Engineering Consulting Limited | Professional & scientific | 2018 |
| Cobra Group Investments Limited | Real estate | 2024 |
| Cobrantis Ltd | Information & communication | 2017 |
| Cobratten LLP | | 2020 |
| Cobrey Limited | Manufacturing | 2025 |
| Cobtree Engineering Company Limited | Manufacturing | 1963 |
| Coburn Consulting Limited | Professional & scientific | 2016 |
| Cocade Trading Limited | Extraterritorial | 2020 |
| Cocards Ltd | Financial services | 2020 |
| Coceca Ltd | Wholesale & retail | 2024 |
| Cochyn Sound Ltd | Information & communication | 2022 |
| Cockatoo Consulting Ltd | Administrative & support | 2009 |
| Cockpitsimparts Limited | Wholesale & retail | 2012 |
| Cocktail Supreme UK Ltd | Wholesale & retail | 2019 |
| Cocky Floors Ltd | Construction | 2026 |
| Coco Azul Ltd | Wholesale & retail | 2022 |
| Coco Digital SW Limited | Wholesale & retail | 2016 |
| Coco Gray Ltd | Professional & scientific | 2025 |
| Coco Hair and Beauty (Rhiwbina) Limited | Other services | 2011 |
| Coco Retreats Limited | Real estate | 2023 |
| Coco SK17 Limited | Hospitality | 2019 |
| Cocoa Plus Ltd | Manufacturing | 2015 |
| Cococo Ltd | Real estate | 2023 |
| Cocodentax Ltd | Manufacturing | 2018 |