| Burlington Electrical Systems Limited | Manufacturing | 2012 |
| Burndine Sales and Services Limited | Professional & scientific | 1970 |
| Business Link Japan Limited | Administrative & support | 2010 |
| Business System Solutions Limited | Professional & scientific | 1986 |
| Busky Limited | Wholesale & retail | 2018 |
| Butland Investments Ltd | Real estate | 2022 |
| Butterwick Kettering Limited | Wholesale & retail | 2021 |
| BY Vixi Limited | Wholesale & retail | 2017 |
| Bybrook Residential Properties Limited | Real estate | 2009 |
| Byeway Logistics Ltd | Transport & logistics | 2021 |
| BYT Enterprises Limited | Professional & scientific | 2014 |
| C & T Macaulay Transport Ltd | Transport & logistics | 2015 |
| C Gamble Construction Ltd | Construction | 2022 |
| C J Packaging Supplies Limited | Administrative & support | 1997 |
| C L Towell & SON (Metals) Ltd | Water & waste | 2013 |
| C R Plumbing East Midlands Ltd | Administrative & support | 2022 |
| C R Services (Corby) Ltd | Manufacturing | 2013 |
| C Vasile Ltd | Wholesale & retail | 2018 |
| C Verty Furniture Ltd | Wholesale & retail | 2009 |
| C&B Smart Solutions Ltd | Wholesale & retail | 2022 |
| C&C Automotors Ltd | Wholesale & retail | 2025 |
| C&C RE Global Ltd | Financial services | 2021 |
| C&G Little LLP | | 2023 |
| C&I Source Ltd | Transport & logistics | 2022 |
| C&L Logistics Limited | Transport & logistics | 2015 |
| C.C.R Electric Ltd | Construction | 2024 |
| C.H.Bennion & Sons Limited | Agriculture & fishing | 1964 |
| C.O Tyres Ltd | Wholesale & retail | 2023 |
| C.R Maintenance Serv. Limited | Construction | 2025 |
| CA Bespoke Solutions Limited | Construction | 2024 |
| Cacco Ltd | Hospitality | 2019 |
| Cafe Mozart Corby Ltd | Hospitality | 2023 |
| Cafe Mozart Ltd | Hospitality | 2018 |
| Cain Cutz Ltd | Other services | 2025 |
| Cairn Imaging Solutions Limited | Extraterritorial | 2024 |
| CAJ IT Ltd | Information & communication | 2018 |
| Calaris Auto Ltd | Wholesale & retail | 2024 |
| Calibra Management Ltd | Hospitality | 2012 |
| Calpaul Serv Limited | Wholesale & retail | 2019 |
| Calsteren Consulting Limited | Real estate | 2002 |
| Camayd Ltd | Health & social care | 2016 |
| Cambridge EBT 2010 Trustees Limited | Professional & scientific | 2014 |
| Cambridge EOT 2014 Trustees Limited | Professional & scientific | 2014 |
| Cambridge Manufacturing Company Limited | Extraterritorial | 2013 |
| Cambridge Nutritional Foods Limited | Professional & scientific | 2005 |
| Cambridge Weight Plan Limited | Manufacturing | 1982 |
| Camcorbhousings Ltd | Real estate | 2024 |
| Camcraft Studio Ltd | Other services | 2024 |
| Camdents Repairs Limited | Wholesale & retail | 2018 |
| Cameron IT Limited | Information & communication | 2018 |
| Camif Limited | Manufacturing | 2014 |
| Camland (Rushden) Limited | Real estate | 2017 |
| Camland Group Limited | Financial services | 2013 |
| Camland Projects Ltd | Real estate | 2015 |
| Campak Limited | Administrative & support | 1978 |
| Campbell Food Management Ltd | Information & communication | 2016 |
| Campbell House Services Ltd | Health & social care | 2020 |
| Campden Fitness Ltd | Arts & recreation | 2020 |
| Camwell Land Limited | Real estate | 2009 |
| Camx Solutions Ltd | Information & communication | 2025 |
| Cancamcctv Limited | Administrative & support | 2011 |
| Canlyn Care Limited | Public administration | 2022 |
| Cannam Hudson Financial Planning Limited | Other services | 2008 |
| Canonbury Group Ltd | Financial services | 2019 |
| Capell Homes Limited | Construction | 2016 |
| Capital Cleaning Solutions Ltd | Administrative & support | 2025 |
| Capitolia Ltd | Wholesale & retail | 2020 |
| Caprae Estates Ltd | Real estate | 2022 |
| Capture Interpreting Services Ltd. | Professional & scientific | 2014 |
| Car House Solutions Ltd | Wholesale & retail | 2015 |
| Car Recruitment UK Limited | Administrative & support | 2024 |
| Car Service Jelonek Ltd | Wholesale & retail | 2022 |
| Car-Mech Ltd | Wholesale & retail | 2025 |
| CAR2GO Vehicle Logistics Ltd | Transport & logistics | 2019 |
| Card & Carry Limited | Wholesale & retail | 2017 |
| Card & Cloud Co Ltd | Wholesale & retail | 2025 |
| Cardiff Executive Centre Limited | Administrative & support | 2004 |
| Cardinal Transport Ltd | Transport & logistics | 2025 |
| Care Bears Healthcare Ltd | Health & social care | 2020 |
| Care Midlands Limited | Real estate | 2012 |
| Caredfor Ltd | Health & social care | 2013 |
| Career Connect Recruit Limited | Administrative & support | 2025 |
| Carefill Ltd | Health & social care | 2018 |
| Carers ARM Support Limited | Health & social care | 2022 |
| Caringtouch Limited | Health & social care | 2022 |
| Carjen Ltd | Health & social care | 2026 |
| Carl Precision Ltd | Information & communication | 2018 |
| Carlisle Care Ltd | Health & social care | 2022 |
| Carmichael Engineering Limited | Manufacturing | 1977 |
| Carol&Dot Construct Ltd | Construction | 2026 |
| Carpet Revive Ltd | Administrative & support | 2026 |
| Carpri Limited | Health & social care | 2014 |
| Carscrathrepair Ltd | Wholesale & retail | 2020 |
| Carson Health & Fitness Ltd | Arts & recreation | 2014 |
| Cartell Commercial Limited | Real estate | 2024 |
| Cartell UK Limited | Manufacturing | 2008 |
| Cartmel Fields Motorsport Camping Ltd | Hospitality | 2024 |
| Carvin Security & Facilities Solutions Ltd | Administrative & support | 2017 |
| Castle Buttons Limited | Manufacturing | 2011 |
| Castle View Events Limited | Real estate | 2017 |