| Byron Court Cheltenham (Management) Company Limited | Households | 1997 |
| Bysheglobal Ltd | Wholesale & retail | 2026 |
| Byte Bolt Ltd | Information & communication | 2023 |
| Byte Vein Ltd | Information & communication | 2025 |
| Bytelotus Ltd | Information & communication | 2026 |
| Bytestream Ltd | Information & communication | 2018 |
| Bythestarz Ltd | Manufacturing | 2025 |
| C & D (Bricklaying Specialists) Limited | Construction | 2003 |
| C & H Catering Ltd | Hospitality | 2026 |
| C & L Cotswold Gardens Ltd | Administrative & support | 2021 |
| C & L Windows & Conservatories Limited | Construction | 2011 |
| C & S Electric Contractors Ltd | Construction | 2023 |
| C and H Collective Ltd | Professional & scientific | 2022 |
| C E Boyes Limited | Professional & scientific | 2015 |
| C E Braddell Limited | Financial services | 2025 |
| C F Cyber Services Limited | Professional & scientific | 2016 |
| C F Roberts (FM) Ltd | Construction | 2003 |
| C G Theron Construction Limited | Construction | 2012 |
| C I S a Limited | Real estate | 1998 |
| C J Cameron Investments Ltd | Real estate | 2024 |
| C J Cook Contractors Ltd | Construction | 2021 |
| C K T Foods Limited | Hospitality | 2024 |
| C M Restaurants (Holdings) Limited | Financial services | 2014 |
| C M Smyth Ltd | Real estate | 2010 |
| C N Baldwin Electrical Limited | Construction | 2011 |
| C P I (UK) Ltd | Hospitality | 2011 |
| C P Kelly Cheltenham Limited | Professional & scientific | 2013 |
| C S Maslin Consultants Limited | Professional & scientific | 2014 |
| C S N Solutions Ltd | Information & communication | 2000 |
| C T a Read Limited | Health & social care | 2017 |
| C W Slatter Holdings Limited | Financial services | 2024 |
| C West Group Holdings Ltd | Financial services | 2025 |
| C&E Diamond Holdings Ltd | Financial services | 2019 |
| C&G Access Ltd | Construction | 2024 |
| C&G Cars Ltd | Transport & logistics | 2016 |
| C&G Dog Park Ltd | Other services | 2025 |
| C&Sj Properties Limited | Real estate | 2021 |
| C&W Investment Properties Limited | Real estate | 2021 |
| C-Retail Limited | Wholesale & retail | 2010 |
| C.A. Honemaster Limited | Manufacturing | 1984 |
| C.C.C. Trading Limited | Wholesale & retail | 1989 |
| C.D. Investments Staverton Limited | Real estate | 2007 |
| C.F. Roberts (Electrical Contractors) Limited | Construction | 1996 |
| C.F.L. Commercials Ltd | Manufacturing | 2009 |
| C.H.Bianco Education Ltd | Information & communication | 2024 |
| C.L.C.M.C. Limited | Households | 1981 |
| C.O.P. Solutions Limited | Construction | 2007 |
| C4LXH Ltd | Hospitality | 2023 |
| C4SEY Developments Ltd | Construction | 2025 |
| C7 Limited | Professional & scientific | 2018 |
| C7 Projects Ltd | Professional & scientific | 2023 |
| CA Consultancy (UK) Limited | Administrative & support | 2012 |
| CAA Property Limited | Real estate | 2013 |
| Caad Building Services Ltd | Administrative & support | 2025 |
| Cab-In-S U.K. Ltd | Construction | 2002 |
| Cabi Properties Limited | Real estate | 2024 |
| Cacklebean Limited | Agriculture & fishing | 2020 |
| Cactus Financial Planning Ltd | Financial services | 2015 |
| CAD Farm Services Limited | Information & communication | 2016 |
| Cadbury Farms Limited | Agriculture & fishing | 2018 |
| Cadcaf Limited | Health & social care | 2006 |
| Cado UK Limited | Professional & scientific | 2008 |
| Cadogan House RTM Company Limited | Households | 2021 |
| Caduce Limited | Extraterritorial | 1998 |
| Caeon Advisory Ltd | Professional & scientific | 2021 |
| Caerleon House Management Company Limited | Households | 2001 |
| Cafe Multa Ltd | Hospitality | 2022 |
| Caffe Torino Limited | Real estate | 2016 |
| CAI Communications Limited | Information & communication | 2013 |
| Caine Property Investments Ltd | Real estate | 2022 |
| Cairn Associates Ltd | Professional & scientific | 2022 |
| Cairnlife Limited | Professional & scientific | 1984 |
| CAJ (Tall Trees) Development Co. Ltd | Construction | 2017 |
| Cajb Enterprise Limited | Administrative & support | 2021 |
| Calathea Solutions Ltd | Education | 2023 |
| Calbarrie Compliance Services Limited | Construction | 2008 |
| Calbarrie Compliance Services Trust Limited | Professional & scientific | 2022 |
| Calcutax Ltd | Extraterritorial | 2011 |
| Caledonian & Abercrombie Limited | Professional & scientific | 2019 |
| Calf Cottage Limited | Real estate | 2023 |
| Caliber Ophthalmics (UK) Limited | Financial services | 2019 |
| Calibruze Ltd | Information & communication | 2023 |
| Calico Jack Construction Limited | Wholesale & retail | 2006 |
| Calligrew Ventures Ltd | Financial services | 2025 |
| Callisto Limited | Information & communication | 1993 |
| Calliv Carpentry Ltd | Construction | 2012 |
| Callosum Solutions Ltd | Professional & scientific | 2021 |
| Calm Housing 2025 Ltd | Real estate | 2025 |
| Calmseas Limited | Financial services | 1999 |
| Calmworld Design Ltd | Professional & scientific | 2025 |
| Calton Road Garage Limited | Wholesale & retail | 2016 |
| Calverley Road Property Fund Limited Partnership | | 2008 |
| Camanderon Limited | Information & communication | 2017 |
| Camarsden Ltd | Construction | 2022 |
| Camberleigh-Hay LLP | | 2009 |
| Camberley Paddock (Aura) Limited | Construction | 2016 |
| Cambray Design Limited | Information & communication | 2007 |
| Cambray Group Limited | Wholesale & retail | 2020 |
| Cambray Property Management Limited | Real estate | 1993 |
| Cambrian Birds Limited | Agriculture & fishing | 2015 |