| CNC World Group Limited | Financial services | 2016 |
| CNC World Limited | Wholesale & retail | 2006 |
| Cncorporation Ltd | Wholesale & retail | 2024 |
| CNE International Limited | Manufacturing | 2007 |
| Cneqt Ltd | Administrative & support | 2000 |
| CNK Consulting Ltd | Financial services | 2018 |
| CNM Developments Limited | Real estate | 2015 |
| CNS Property Management Ltd | Real estate | 2015 |
| Co Implants Ltd | Health & social care | 2024 |
| Coach and Horses Norwich Limited | Hospitality | 2020 |
| Coach Time Ltd | Administrative & support | 2017 |
| Coaching With Kooks Ltd | Professional & scientific | 2024 |
| Coachman's Court Residents Association Limited | Real estate | 1985 |
| Coachpositive Ltd | Professional & scientific | 2007 |
| Coal Medical Ltd | Administrative & support | 2019 |
| Coalescence Consulting Limited | Professional & scientific | 2006 |
| Coals 4 YOU NW Limited | Wholesale & retail | 2015 |
| Coast & Country Builders Ltd | Construction | 2017 |
| Coast and Country Estate Agents Ltd | Real estate | 2019 |
| Coast to Coast Contractors Ltd | Construction | 2007 |
| Coastal Buoy Properties Ltd | Real estate | 2026 |
| Coastal Exploration Company Limited | Administrative & support | 2015 |
| Coastal GAS Supplies Ltd | Wholesale & retail | 2018 |
| Coastal International Ltd | Construction | 2020 |
| Coastal Villa Ltd | Wholesale & retail | 2018 |
| Coastal Window Cleaning Ltd | Administrative & support | 2022 |
| Coastcars Ltd | Wholesale & retail | 2023 |
| Coastguards Contemporary Limited | Wholesale & retail | 2021 |
| Coastline Construction Norfolk Ltd | Construction | 2023 |
| Coates Collective Ltd | Real estate | 2025 |
| Cobalt Pharma Consultancy Limited | Professional & scientific | 2016 |
| Cobbs Place (Great Yarmouth) Limited | Households | 1989 |
| Cobuild (Norfolk) Ltd | Construction | 2018 |
| Cocina MIA Ltd | Hospitality | 2023 |
| Cock & Bull Investments Ltd | Financial services | 2019 |
| Coconut Octopus Limited | Professional & scientific | 2018 |
| Cocoon Properties Limited | Real estate | 2020 |
| Cocos Dessert Ltd | Hospitality | 2022 |
| Coda Films Limited | Information & communication | 2015 |
| Code Monkey I.T. Limited | Information & communication | 2003 |
| Code Ninja Ealing Ltd | Education | 2019 |
| Codeco Limited | Administrative & support | 1986 |
| Codecoded Limited | Other services | 2018 |
| Codefish Apps Ltd | Information & communication | 2014 |
| Codeflux Ltd | Information & communication | 2015 |
| Codekconsulting Ltd | Information & communication | 2024 |
| Codentra Limited | Information & communication | 2026 |
| Coder Agency Ltd | Professional & scientific | 2025 |
| Codford Biogas Limited | Energy | 2012 |
| Coding Powers Limited | Information & communication | 2009 |
| Codrington Energy Centre Ltd | Energy | 2021 |
| COE, Costa & Moore Holdings Limited | Financial services | 2024 |
| COE, Costa & Moore Limited | Wholesale & retail | 2012 |
| Coegunnell Limited | Professional & scientific | 2022 |
| Coen Media Limited | Information & communication | 2018 |
| Coeus Publishing Ltd | Information & communication | 2023 |
| Coffee & Beer Commercial Holdings Limited | Construction | 2021 |
| Coffee and Liquor Ltd | Wholesale & retail | 2023 |
| Coffee Quest Ltd | Wholesale & retail | 2014 |
| Coffee Rites Limited | Hospitality | 2009 |
| Coffeesmiths Limited | Hospitality | 2022 |
| Coffi House Ltd | Hospitality | 2019 |
| Cofradia 2.0 Ltd | Manufacturing | 2023 |
| Cogen Technical Services Ltd | Professional & scientific | 2007 |
| Cogiledger Ltd | Professional & scientific | 2019 |
| Cogknow Limited | Wholesale & retail | 2010 |
| Cogmentum Events Limited | Administrative & support | 2018 |
| Cogmentum Holdings Ltd | Financial services | 2025 |
| Cognisance Healthcare Consulting Limited | Professional & scientific | 2019 |
| Cognition Training Ltd | Other services | 2021 |
| Cohen Knights LLP | | 2017 |
| Cohen Knights Trustees Ltd | Professional & scientific | 2018 |
| Cohen Orthopaedics Limited | Health & social care | 2012 |
| Cohn's Transport Services Ltd | Transport & logistics | 2020 |
| Cohorted Communications Limited | Other services | 2019 |
| Cojan Investment Ltd | Real estate | 2025 |
| Cojo Limited | Real estate | 2024 |
| Coker Brand Design Limited | Arts & recreation | 2011 |
| Colauf UK CIC | Arts & recreation | 2026 |
| Colchester Family Limited | Hospitality | 2024 |
| Coldflint Limited | Information & communication | 2026 |
| Coldham Hall Sailing Club (2009) Limited | Arts & recreation | 2009 |
| Coldwell Barnum Holdings Limited | Construction | 2024 |
| Cole Agricultural Ltd | Professional & scientific | 2017 |
| Cole Project Management Limited | Professional & scientific | 2012 |
| Cole Property Holdings Ltd | Real estate | 2026 |
| Coleman Construction Management Ltd | Construction | 2018 |
| Coleman Contracts Limited | Agriculture & fishing | 2006 |
| Coleman Fibre Solutions Ltd | Information & communication | 2025 |
| Coleman Films Limited | Information & communication | 2024 |
| Coleman Opticians Limited | Wholesale & retail | 1998 |
| Coleman Post Production Ltd | Information & communication | 2023 |
| Coleman Television Group Limited | Information & communication | 2021 |
| Coleman Television Limited | Professional & scientific | 2020 |
| Colemill Construction Ltd | Construction | 2012 |
| Colemill Ltd | Construction | 2014 |
| Coleridge Financial Limited | Professional & scientific | 2009 |
| Colgar Ltd | Real estate | 2004 |
| Colin Chapman Foundation | Education | 2016 |
| Colin Feltham Design & Reports Ltd | Professional & scientific | 2004 |