| CM Courier Group Ltd | Transport & logistics | 2026 |
| CM Electrical Installs Ltd | Construction | 2024 |
| CM Mcevoy Ltd | Construction | 2018 |
| CM Physio and Injury Management Limited | Health & social care | 2015 |
| CM Project Management Ltd | Professional & scientific | 2023 |
| CM Recoveries Ltd | Transport & logistics | 2025 |
| CM Utilities (NE) Ltd | Construction | 2025 |
| CMC Safety Solutions Ltd | Professional & scientific | 2025 |
| CMG Prestige Motors Limited | Wholesale & retail | 2024 |
| CMJ Fitness Ltd | Arts & recreation | 2020 |
| CML Sustain (Documentation) Limited | Construction | 2011 |
| CMP Marketing Limited | Professional & scientific | 1921 |
| CMS Business Consultancy Ltd | Professional & scientific | 2019 |
| Cmwb Services Limited | Construction | 2026 |
| Cmwwy Properties Limited | Real estate | 2019 |
| CN Electrical Services Ltd | Construction | 2024 |
| CN Software Solutions Ltd | Information & communication | 2015 |
| CNE Trading Ltd | Health & social care | 2016 |
| CNS Kitchens Ltd | Hospitality | 2019 |
| Cnstncy Ltd. | Professional & scientific | 2025 |
| Cntechne Limited | Other services | 2022 |
| Co-Navigate Limited | Professional & scientific | 2014 |
| Co-Wheels Car Club Community Interest Company | Administrative & support | 2008 |
| Co-Wheels UK Limited | Financial services | 2018 |
| CO4CH Ltd | Information & communication | 2025 |
| Coach House Drive Management Company Limited | Real estate | 2020 |
| Coach House Gosforth Management Limited | Real estate | 2019 |
| Coachedbyloz at Olympia Gym NCL Ltd | Arts & recreation | 2021 |
| Coachhouse 8 Limited | Professional & scientific | 2009 |
| Coal Face Development Limited | Extraterritorial | 2007 |
| Coal House Property Ltd | Real estate | 2024 |
| Coalface Records Limited | Wholesale & retail | 2026 |
| Coalition for Marriage Limited | Other services | 2011 |
| Coalshed Investments Ltd | Financial services | 2018 |
| Coan Marketing Consultancy Ltd | Professional & scientific | 2026 |
| Coast & Country Stays Ltd | Real estate | 2022 |
| Coast Road North East Ltd | Hospitality | 2024 |
| Coast Vintage Ltd | Wholesale & retail | 2022 |
| Coastal Building Associates Limited | Construction | 2019 |
| Coastal Hampers North East Ltd | Wholesale & retail | 2021 |
| Coastal Matters Ltd | Professional & scientific | 2014 |
| Coatham Vale and Berrymead Gardens Residents Management Company Limited | Real estate | 2022 |
| Coating Consultancy Limited | Construction | 2025 |
| Coating Consultants International Ltd | Professional & scientific | 2021 |
| Coatsbay Limited | Financial services | 2026 |
| Coatsworth EYE Clinic Limited | Health & social care | 2013 |
| Coatworth Supermarket Ltd | Wholesale & retail | 2024 |
| Cobalt Energy Consulting Ltd | Professional & scientific | 2018 |
| Cobalt ICT Limited | Information & communication | 2005 |
| Cobalt Motors Ltd | Wholesale & retail | 2020 |
| Cobalt Three Limited | Real estate | 2001 |
| Cobalt TOO C.I.C. | Arts & recreation | 2014 |
| Cobb Properties NE Limited | Real estate | 2020 |
| Cobo Biosolutions Limited | Manufacturing | 2026 |
| Cobra Boxing and Fitness Limited | Arts & recreation | 2025 |
| Cobra Security Services Limited | Administrative & support | 2002 |
| Cocafood Ltd | Extraterritorial | 2014 |
| Cochrane Park Properties 2 Limited | Real estate | 2022 |
| Cochrane Park Properties Limited | Real estate | 2010 |
| Cochrane Park Wines Ltd | Wholesale & retail | 2008 |
| Cochrane Properties NE Ltd | Real estate | 2026 |
| Cock a Snook Limited | Other services | 2009 |
| Cockerel Software Limited | Information & communication | 1998 |
| Coco Luminaire (NE) Ltd | Administrative & support | 2023 |
| Coco Palm Limited | Other services | 2024 |
| Coco Vending Services Ltd | Wholesale & retail | 2024 |
| Coco's Tanning Lounge Ltd | Other services | 2024 |
| Cocochine Town Limited | Hospitality | 2025 |
| COD Consulting Limited | Professional & scientific | 2017 |
| COD Fella's Fish and Grill Ltd | Hospitality | 2022 |
| Code & Cart Limited | Wholesale & retail | 2025 |
| Code Group Ltd | Financial services | 2020 |
| Code Group Music Limited | Information & communication | 2025 |
| Code Group Music Publishing Limited | Information & communication | 2025 |
| Code Media and Entertainment Ltd | Arts & recreation | 2024 |
| Codename Films Ltd | Information & communication | 2023 |
| Codename Music Ltd | Information & communication | 2018 |
| Coding Bespoke Solutions Limited | Information & communication | 2023 |
| Coffee Club Cafe Limited | Hospitality | 2018 |
| Coffee Derya Ltd | Wholesale & retail | 2023 |
| Coffee Design Limited | Professional & scientific | 2006 |
| Coffee on the Corner Chapel House Ltd | Hospitality | 2020 |
| Coffee on the Corner Lemington Ltd | Hospitality | 2017 |
| Cofrescofood Limited | Hospitality | 2025 |
| Cofrescofood Two Limited | Hospitality | 2025 |
| Cofton Consulting Ltd | Professional & scientific | 2023 |
| COG and Wheel Limited | Hospitality | 2020 |
| COG Property Renovations Ltd | Construction | 2026 |
| COG Trading Limited | Wholesale & retail | 2023 |
| Cognassist UK Limited | Information & communication | 2019 |
| Cognatio Limited | Administrative & support | 2006 |
| Cognisant Health CIC | Public administration | 2021 |
| Cognitive Behavioural Psychotherapy Ltd | Health & social care | 2014 |
| Cohda Properties Ltd | Financial services | 2025 |
| COHERE360 Limited | Information & communication | 2019 |
| Coherent 360 Ltd | Information & communication | 2023 |
| Cohesion Cost Consultants Ltd | Professional & scientific | 2016 |
| Cohesive HR Limited | Professional & scientific | 2021 |
| Cohousing Upon Tyne Limited | Real estate | 2018 |
| Coimbatore Foods Ltd | Hospitality | 2021 |