| Concinne Ltd | Information & communication | 2014 |
| Concisehr Ltd | Professional & scientific | 2014 |
| Conclavia Limited | Wholesale & retail | 2017 |
| Condition Code Ltd | Arts & recreation | 2023 |
| Conduction (UK) Ltd | Construction | 2003 |
| Conexsell Limited | Real estate | 2020 |
| Coney Grey Interiors Ltd | Professional & scientific | 2019 |
| Confera Ltd | Construction | 2026 |
| Conisborough Furniture Components Limited | Professional & scientific | 1993 |
| Coniston Peak Limited | Financial services | 2020 |
| Conkova Ltd | Administrative & support | 2024 |
| Connect a Trade Ltd | Information & communication | 2021 |
| Connect Derby Properties Ltd | Real estate | 2020 |
| Connect Equine Ltd | Wholesale & retail | 2020 |
| Connect MSK Limited | Health & social care | 2015 |
| Connect My Event Limited | Information & communication | 2013 |
| Connect Outreach CIC | Administrative & support | 2025 |
| Connected Perinatal Support CIC | Health & social care | 2021 |
| Connective Consulting Limited | Information & communication | 2016 |
| Connectnow UK Limited | Information & communication | 2019 |
| Connectwise Academy Ltd | Education | 2024 |
| Connetick Limited | Professional & scientific | 2017 |
| Connieford Ltd | Real estate | 2022 |
| Conny-Business-Coaching Ltd. | Wholesale & retail | 2024 |
| Conrad Holdings Limited | Real estate | 2016 |
| Conroy Property Group Ltd | Real estate | 2025 |
| Conscientious Communications Limited | Administrative & support | 2013 |
| Consenso Ltd | Professional & scientific | 2017 |
| Consider Safety Limited | Administrative & support | 2023 |
| Considered Homes Limited | Real estate | 2025 |
| Constellation Supply Group Ltd | Wholesale & retail | 2020 |
| Construct Project Management Limited | Professional & scientific | 2023 |
| Constructcraze Limited | Construction | 2026 |
| Constructing Futures Ltd | Other services | 2025 |
| Construction & Cladding Services Limited | Construction | 2004 |
| Construction & Commissioning Consultants (UK) Ltd | Professional & scientific | 2025 |
| Construction &Cos&Ion Limited | Construction | 2023 |
| Construction 24 Limited | Construction | 2003 |
| Construction Cosmetics Limited | Construction | 2012 |
| Consult Property Ltd | Real estate | 2021 |
| Consultnow IT Solutions Limited | Information & communication | 2019 |
| Contact Property Services Limited | Financial services | 1979 |
| Container Recovery Services Limited | Real estate | 1998 |
| Contex UK Limited | Wholesale & retail | 2002 |
| Context Window Labs Ltd | Professional & scientific | 2025 |
| Contrail Flight Service Limited | Transport & logistics | 2005 |
| Contrak Construction Ltd | Construction | 2017 |
| Contrak Holdings Limited | Financial services | 2016 |
| Contrak Limited | Construction | 2005 |
| Contrast Studio Ltd | Real estate | 2019 |
| Contribute 100 Ltd | Professional & scientific | 2025 |
| Contrive Consultants Limited | Professional & scientific | 2024 |
| Control-Dot Ltd | Information & communication | 2018 |
| Conundrum Solutions Limited | Information & communication | 2007 |
| Convert Technologies Limited | Information & communication | 2016 |
| Conveyor Solutions Limited | Professional & scientific | 2019 |
| Cook & Foster Limited | Real estate | 2025 |
| Cooke-Yeomans Consulting Limited | Professional & scientific | 2017 |
| Cookie 360 Consulting Ltd | Professional & scientific | 2026 |
| Cooking UP Media Limited | Information & communication | 2016 |
| Cool Peak Group Ltd | Manufacturing | 2024 |
| Coomtech Ltd | Manufacturing | 2011 |
| Cooper Parry Advisory Limited | Professional & scientific | 2022 |
| Cooper Parry Audit Holdings Limited | Financial services | 2022 |
| Cooper Parry Audit LLP | | 2022 |
| Cooper Parry Digital Limited | Financial services | 2024 |
| Cooper Parry Group Holdings Limited | Financial services | 2022 |
| Cooper Parry Group Limited | Information & communication | 2011 |
| Cooper Parry Law LLP | | 2013 |
| Cooper Parry LLP | | 2002 |
| Cooper Parry Trustees Limited | Extraterritorial | 2008 |
| Cooper Parry Wealth (TW) Limited | Financial services | 2015 |
| Cooper Parry Wealth Limited | Financial services | 2001 |
| Cooper Property Holdings Ltd | Real estate | 2024 |
| Cooper Property Lettings Ltd | Real estate | 2026 |
| Cooper Rylatt Limited | Professional & scientific | 2014 |
| Coote Investment Group Ltd | Financial services | 2023 |
| Coote's Industrial Roofing & Cladding Ltd | Construction | 2017 |
| Cootehill Food Group Limited | Extraterritorial | 2018 |
| Cootehill Poultry Products Limited | Wholesale & retail | 2013 |
| Copemann Ashby Limited | Real estate | 2011 |
| Copo Technology Limited | Information & communication | 2018 |
| Copop Management Limited | Real estate | 2026 |
| Copper Electrical Ltd | Construction | 2018 |
| Copper Sky Limited | Education | 2023 |
| Coppice Park (Draycott) Management Company Limited | Households | 2006 |
| Coppice Professional Ltd | Construction | 2012 |
| Coppice Services Ltd | Hospitality | 2020 |
| Coppicewood IP Ltd | Professional & scientific | 2025 |
| Copula Services Ltd | Information & communication | 2026 |
| Copy That! Midlands Ltd | Professional & scientific | 2023 |
| Coralia Transport Ltd | Wholesale & retail | 2017 |
| Corbel Residential Ltd | Real estate | 2023 |
| Corbin House Associates Limited | Wholesale & retail | 2020 |
| CORBY37 Ltd | Manufacturing | 2023 |
| Cordwell Quantity Surveying Services Ltd | Construction | 2018 |
| Core Capital Management Ltd | Financial services | 2026 |
| Core Competitions Limited | Other services | 2021 |
| Core Driver Training (Derby) Ltd | Education | 2026 |
| Core Joinery Limited | Construction | 2016 |