| Codecrest Limited | Extraterritorial | 1987 |
| Coded Cat Ltd | Information & communication | 2024 |
| Codeias Limited | Administrative & support | 2015 |
| Coefficient Care Limited | Financial services | 2013 |
| Cogent Hire Limited | Financial services | 2020 |
| Cojoc Couriers Ltd | Transport & logistics | 2026 |
| COL Group Ltd | Construction | 2019 |
| Colbeck Consultants Limited | Health & social care | 2014 |
| Colchester Oysters Ltd | Wholesale & retail | 2018 |
| Cold HUT Recovery Ltd | Other services | 2023 |
| Cold Kitchen Ltd | Wholesale & retail | 2024 |
| Coles Electrical and Fire Safety Limited | Administrative & support | 2013 |
| Colette Jolly Compliance Consultants Limited | Professional & scientific | 2016 |
| Colian Developments Ltd | Construction | 2017 |
| Colin Clayton Limited | Transport & logistics | 2006 |
| Colin Harris Ltd | Health & social care | 2013 |
| Collective Payments Limited | Administrative & support | 2012 |
| Colliers Arms (Chorley) Ltd | Hospitality | 2021 |
| Collingwood Bespoke Play Ltd | Manufacturing | 2023 |
| Collingwood Electrical Limited | Construction | 2004 |
| Collingwood Electrical NW Limited | Construction | 2025 |
| Collins Site Services Limited | Manufacturing | 2012 |
| Colne Valley Decking & Fencing Limited | Wholesale & retail | 2009 |
| Colour Boutique Ltd | Other services | 2018 |
| Commercial Garden Maintenance Ltd | Administrative & support | 2018 |
| Communal Space Maintenance & Gardens Ltd | Construction | 2018 |
| Communal Vision Ltd | Information & communication | 2019 |
| Community Arts Development CIC | Education | 2016 |
| Community Care Team Ltd | Health & social care | 2006 |
| Community Film Art & Media CIC | Arts & recreation | 2016 |
| Community Veterans Events Team CIC | Arts & recreation | 2025 |
| Comodica Ltd | Wholesale & retail | 2018 |
| Compactors Direct Limited | Wholesale & retail | 1987 |
| Compactors Direct Servicing Limited | Manufacturing | 1998 |
| Compare Advantage Ltd | Information & communication | 2022 |
| Compare Home Design Ltd | Other services | 2020 |
| Compare-Containers Ltd | Wholesale & retail | 2019 |
| Compass Fire Safety Solutions Ltd | Professional & scientific | 2026 |
| Compass Qualifications Limited | Education | 2025 |
| Compass Skills Training Limited | Public administration | 2017 |
| Compelling Writing Limited | Administrative & support | 2016 |
| Competence Training Solutions Ltd | Education | 2020 |
| Complete Clad Envelope Facades Ltd | Construction | 2020 |
| Complete Construction 1 Ltd | Construction | 2018 |
| Complete Cool Limited | Construction | 2021 |
| Complete Heating NW Ltd | Construction | 2015 |
| Complete ITC Limited | Information & communication | 2011 |
| Complete School Solutions Ltd | Administrative & support | 2026 |
| Complete Security Gates Ltd | Administrative & support | 2021 |
| Complete Textile Solutions Ltd | Professional & scientific | 2011 |
| Concert Health Care Limited | Construction | 2014 |
| Concert Healthcare NO 2 Ltd | Health & social care | 2021 |
| Concert Healthcare NO 3 Ltd | Health & social care | 2025 |
| Concert Healthcare Property Holdings Ltd | Financial services | 2021 |
| Concise Project Management Ltd | Professional & scientific | 2018 |
| Concorde Capital Limited | Financial services | 2014 |
| Confettibee Ltd | Wholesale & retail | 2022 |
| Conna O'Grady Construction Ltd | Construction | 2021 |
| Connect Comms Holdings Limited | Financial services | 2020 |
| Connected Electrical Contractors North West Ltd | Construction | 2019 |
| Connected Executives Ltd | Administrative & support | 2020 |
| Connected Families - Autism and Mental Health Ltd | Health & social care | 2024 |
| Connected Learning Ltd | Education | 2025 |
| Conroy's Coffee Ltd | Hospitality | 2016 |
| Conscious Connections Ltd | Education | 2021 |
| Conservatory Medic Limited | Administrative & support | 2015 |
| Consilium Services Ltd | Professional & scientific | 2019 |
| Consilium Wealth Management Ltd | Professional & scientific | 2018 |
| Constellation Financial Solutions Limited | Financial services | 2011 |
| Construct 4 Limited | Real estate | 2019 |
| Construct Flooring Solutions Ltd | Construction | 2024 |
| Construction Consultancy Services (NW) Limited | Construction | 2025 |
| Construction Techniques Limited | Construction | 1989 |
| Construction Ventures Limited | Administrative & support | 2016 |
| Consultability Finance Limited | Professional & scientific | 2017 |
| Consultants of Financial Services Limited | Professional & scientific | 2014 |
| Consumer Credit Solutions Limited | Administrative & support | 2017 |
| Content Media Revolution Limited | Wholesale & retail | 2009 |
| Contours Hair & Skin Clinic Limited | Other services | 2024 |
| Contract Brickwork Ltd | Construction | 2008 |
| Contract Services (Millenium) Limited | Administrative & support | 2004 |
| CONTRACT2017 Limited | Transport & logistics | 2018 |
| Convar Developments Ltd | Construction | 2020 |
| Convene Holdings Ltd | Financial services | 2025 |
| Convene IT Limited | Information & communication | 2008 |
| Convenience Ltd | Wholesale & retail | 2018 |
| Convertoo Ltd | Information & communication | 2023 |
| Cookies & Cream Beds Ltd | Other services | 2015 |
| Cookson & Clegg Limited | Manufacturing | 1990 |
| Cool Logistics Resources Limited | Administrative & support | 2011 |
| Cool White Electrical Limited | Construction | 2024 |
| Coolguard Refrigeration Limited | Manufacturing | 2018 |
| Coolservice Refrigeration Limited | Manufacturing | 2021 |
| Coomer Associates Limited | Real estate | 2015 |
| Cooper Bespoke Joinery Limited | Construction | 2007 |
| Cooper Car & Commercial Vehicle Painters Limited | Wholesale & retail | 2012 |
| Coopers Taxis Limited | Transport & logistics | 2014 |
| Copper on the Green Ltd | Manufacturing | 2025 |
| Coppertop Interiors Ltd | Professional & scientific | 2019 |
| Coppull Car & Commercial Repair Centre Ltd | Wholesale & retail | 2020 |