| Cornfield Building Services Limited | Construction | 2016 |
| Cornfield IT Ltd | Information & communication | 2014 |
| Cornfield Property Trading Ltd | Real estate | 2024 |
| Cornfield Roofing Limited | Construction | 2016 |
| Cornfield Scaffolding Ltd | Construction | 2015 |
| Cornhill Commercial LLP | | 2019 |
| Cornhill Enterprises Limited | Real estate | 2019 |
| Cornwall and Sons Haulage and Logistics Limited | Transport & logistics | 2021 |
| Cornwall Insight Group Limited | Financial services | 2017 |
| Cornwall Insight Ltd | Information & communication | 2005 |
| Cornwick Limited | Construction | 2025 |
| Cornwick One Ltd | Real estate | 2025 |
| Corporate Alchemy Limited | Professional & scientific | 1999 |
| Corporate Recovery and Finance Ltd | Professional & scientific | 2022 |
| Correct Solutions Limited | Construction | 2017 |
| Cortex Roofing Limited | Construction | 2021 |
| Coruscate Limited | Professional & scientific | 2022 |
| Corvus Education Trust | Education | 2016 |
| Cosmas Online Ltd | Wholesale & retail | 2022 |
| Cosmic Characters Ltd | Wholesale & retail | 2023 |
| Cosmopolaris Ltd | Construction | 2024 |
| Costessey (Norwich) Holding Limited | Professional & scientific | 2010 |
| Costessey (Norwich) Limited | Wholesale & retail | 2001 |
| Costessey Community Events C.I.C. | Arts & recreation | 2023 |
| Costessey Hand Car Wash Ltd | Other services | 2026 |
| Costessey Inns Ltd | Professional & scientific | 2010 |
| Costessey Shopper Ltd | Administrative & support | 2023 |
| Costessey Windows & Doors Limited | Construction | 2002 |
| Costessy Hand Car Wash Ltd | Administrative & support | 2025 |
| Coston Hall Farm Limited | Agriculture & fishing | 1987 |
| Coston Lakes Ltd | Agriculture & fishing | 2015 |
| Cosu Studio Ltd | Professional & scientific | 2025 |
| Cosy Carpets & Comfy Beds Limited | Wholesale & retail | 2003 |
| Cosy Cat Developments Ltd | Construction | 2006 |
| Cosy Post Production Ltd | Information & communication | 2017 |
| COT FAB Ltd | Manufacturing | 2024 |
| Cotenham Barn Limited | Hospitality | 2014 |
| Cotmer H&R Ltd | Administrative & support | 2024 |
| Cotmer Holdings Limited | Real estate | 2022 |
| Cotmer Storage Limited | Administrative & support | 2008 |
| Cotswold Balloon Safaris Limited | Arts & recreation | 2014 |
| Cotswold Bells Ltd | Hospitality | 2024 |
| Cottage 9 Ltd | Hospitality | 2025 |
| Cottage Holdings Ltd | Hospitality | 2023 |
| Cottage Maintenance Limited | Hospitality | 2006 |
| Cottages and Houses Property Ltd | Real estate | 2006 |
| Cotton Claud Limited | Arts & recreation | 2026 |
| Cottoncomfortuk Ltd | Other services | 2017 |
| Coulby Developments Limited | Real estate | 2015 |
| Counter Extremism Project UK | Education | 2021 |
| Country and Eastern Limited | Wholesale & retail | 1982 |
| Country Blinds and Shutters Ltd | Construction | 2019 |
| Country Holiday Cottages Norfolk Limited | Hospitality | 2008 |
| Country Kitchen Foods (Norfolk) Ltd | Administrative & support | 2016 |
| Country View House Limited | Real estate | 2026 |
| Countrywide Legal Indemnities Limited | Financial services | 1994 |
| Countsequential Limited | Professional & scientific | 2006 |
| County Damp Proofing East Limited | Construction | 2022 |
| County Farm Barn Ltd | Real estate | 2024 |
| County Property Services (Norfolk) Ltd | Construction | 2018 |
| County Rentals Limited | Real estate | 2009 |
| Courage Noble Men's Grooming Ltd | Other services | 2016 |
| Courier NOW Ltd | Transport & logistics | 2021 |
| Court Park Financial Services Limited | Professional & scientific | 2009 |
| Courtney Property Ltd | Real estate | 2024 |
| Cove Hope Ltd | Health & social care | 2026 |
| Covegate Limited | Agriculture & fishing | 2013 |
| Coventry Roof Trim Ltd | Construction | 2019 |
| Cover Consulting Ltd | Professional & scientific | 2017 |
| Coveriq Holdings Ltd | Financial services | 2026 |
| Coveriq Ltd | Financial services | 2025 |
| COW Hill Creative Ltd | Information & communication | 2012 |
| Cowcross Limited | Information & communication | 2014 |
| Cowellmedi UK Limited | Wholesale & retail | 2025 |
| Cowills Building Limited | Construction | 2022 |
| Cowling & Co Engineering Limited | Manufacturing | 2022 |
| COX Capital Ltd | Administrative & support | 2020 |
| Coxall Brickwork Ltd | Construction | 2025 |
| Cozens (UK) Limited | Construction | 2014 |
| Cozens Wiley Management Limited | Real estate | 2008 |
| Cozens-Hardy & Jewson Limited | Professional & scientific | 1988 |
| Cozens-Hardy LLP | | 2007 |
| Cozinha Amor Ltd | Hospitality | 2026 |
| CP Groundworks Limited | Construction | 2014 |
| CP Transport Solutions Ltd | Transport & logistics | 2016 |
| CP5 Limited | Hospitality | 2002 |
| CPA Croyabl Ltd | Wholesale & retail | 2023 |
| CPD Aviation Services Ltd | Education | 2023 |
| CPE Trust Co NO.1 Ltd | Extraterritorial | 2023 |
| CPE Trust Co NO.2 Ltd | Extraterritorial | 2023 |
| CPE Trust Co NO.3 Ltd | Extraterritorial | 2023 |
| CPE Trust Co NO.4 Ltd | Extraterritorial | 2023 |
| CPK 24 Ltd | Hospitality | 2024 |
| CPP Solutions Limited | Information & communication | 2016 |
| CPS France Ltd | Professional & scientific | 2023 |
| CR Carpentry (Norfolk) Ltd | Construction | 2017 |
| CR Entertainments Limited | Arts & recreation | 2017 |
| CR Network Solutions Ltd | Information & communication | 2020 |
| CRA Holdings Ltd | Financial services | 2024 |
| Crabb & FOX Mobile Bar Limited | Hospitality | 2024 |