| CL Controls Limited | Professional & scientific | 2023 |
| CL Plumbing & Heating Solutions Ltd | Construction | 2022 |
| Cladanco Limited | Construction | 1994 |
| Cladding Project Management Limited | Construction | 2021 |
| Clade Advisory Limited | Professional & scientific | 2024 |
| Clade Engineering Systems Group Ltd | Manufacturing | 2014 |
| Clade Engineering Systems Ltd | Manufacturing | 2008 |
| Clade Ltd | Manufacturing | 2018 |
| Claden Limited | Construction | 2006 |
| Cladvis Ltd | Construction | 2018 |
| Claerwen Management NO.1 Limited | Real estate | 2000 |
| Claim Repairs Limited | Water & waste | 2025 |
| Claimblock Property Management Limited | Real estate | 1987 |
| Claire Body Consulting Ltd | Administrative & support | 2026 |
| Claire Cook Counselling and Psychotherapy Ltd | Extraterritorial | 2025 |
| Claire Coulthard Photography Ltd | Professional & scientific | 2025 |
| Claire Davis Consulting Ltd | Professional & scientific | 2025 |
| Claire Hancock Rehabilitation Ltd | Health & social care | 2014 |
| Claire Lawson Associates Ltd | Professional & scientific | 2023 |
| Claire Lifestyle Ltd | Other services | 2017 |
| Claire Merrick Consulting Limited | Professional & scientific | 2011 |
| Claire's Nouveau Limited | Wholesale & retail | 2026 |
| Clamp Developments Ltd | Construction | 2019 |
| Clanage Road Sports Club Limited | Arts & recreation | 2013 |
| Clanberris Court Management Limited | Real estate | 2017 |
| Clancy Building Services Limited | Construction | 1996 |
| Clandean Property Management Limited | Construction | 1985 |
| Clandillon Site Services Limited | Construction | 2020 |
| Clanna Investments Ltd | Real estate | 2021 |
| Clapham Cafes Ltd | Hospitality | 2013 |
| Clapton Farm Solar Park Limited | Energy | 2012 |
| Clapton Hospitality Ltd | Hospitality | 2024 |
| Claralabs Ltd | Information & communication | 2026 |
| Clare AS MUD Limited | Arts & recreation | 2004 |
| Clare Base Ltd | Professional & scientific | 2024 |
| Clare Crossley Ltd | Other services | 2023 |
| Clare House RTM Company Limited | Households | 2022 |
| Clare House Surgical Limited | Health & social care | 2012 |
| Clare Keyte Limited | Information & communication | 2017 |
| Clare Preskett Limited | Administrative & support | 2022 |
| Clarehill Associates Ltd | Administrative & support | 2003 |
| Claremont Ferrand Limited | Real estate | 2002 |
| Claremont Flats (Bristol) Management Ltd. | Households | 1987 |
| Claremont Real Estate Investments Limited | Real estate | 2021 |
| Clarence Court (Wotton-Under-Edge) Limited | Households | 1990 |
| Clarence Media Ltd | Professional & scientific | 2026 |
| Clarendon (Frenchay) Management Company Limited | Households | 2004 |
| Clarendon House Management Company Limited | Households | 1989 |
| Claridge Capital Developments Ltd | Construction | 2023 |
| Claridge Scaffolding Ltd | Construction | 2022 |
| Clarion Marketing Limited | Administrative & support | 2014 |
| Clarity Building Consultancy Ltd | Professional & scientific | 2025 |
| Clarity Consultancy Services Limited | Professional & scientific | 2008 |
| Clarity Data Ltd | Information & communication | 2023 |
| Clarity Executive Limited | Administrative & support | 2026 |
| Clarity Information Solutions Limited | Information & communication | 2007 |
| Clarity NOW Assessments Ltd | Health & social care | 2026 |
| Clarity Research Ltd. | Information & communication | 2016 |
| Clarity Safety Solutions Limited | Professional & scientific | 2007 |
| Clarity Valuations Ltd | Financial services | 2016 |
| Claritydw Limited | Information & communication | 2015 |
| Clarityelevate Ltd | Professional & scientific | 2025 |
| Clarius Solutions Limited | Information & communication | 2015 |
| Clark Business Services Limited | Professional & scientific | 2011 |
| Clark Engineering (Bristol) Limited | Professional & scientific | 2006 |
| Clark Insurance UK Ltd | Financial services | 2010 |
| Clark Jackson Ltd | Real estate | 2014 |
| Clark Wood Holdings Limited | Administrative & support | 2024 |
| Clark Wood Limited | Administrative & support | 2011 |
| Clark's Plant Services Ltd | Manufacturing | 2025 |
| Clarke and Co Autos Limited | Wholesale & retail | 2025 |
| Clarke Brothers Scaffolding Limited | Construction | 2002 |
| Clarke Carpentry Contractors Ltd | Construction | 2019 |
| Clarke Preston Group Limited | Financial services | 2025 |
| Clarke Procurement & Supply Services Limited | Professional & scientific | 2011 |
| Clarke Project Services Ltd | Administrative & support | 2026 |
| Clarke Robinson & Co Ltd | Financial services | 2005 |
| Clarke Robinson Retirement Planning Ltd | Other services | 2022 |
| Clarkes Construction (Bristol) Ltd | Construction | 2024 |
| Clarkes Labour Ltd | Construction | 2025 |
| Clarks Ashbury Limited | Real estate | 2020 |
| Clarks of Bristol Ltd | Manufacturing | 2022 |
| Clarks Pies Limited | Manufacturing | 2002 |
| Clarmond Family Office Limited | Professional & scientific | 2021 |
| Class 06 Limited | Professional & scientific | 2006 |
| Class a Paving (Bristol) Limited | Construction | 2016 |
| Class ACT Scaffolding Ltd | Construction | 2023 |
| Class Aviation Ltd | Professional & scientific | 2026 |
| Class Blaze Ltd | Wholesale & retail | 2025 |
| Class Recruitment Limited | Administrative & support | 2009 |
| Classic Algorithm Limited | Information & communication | 2024 |
| Classic Cleaning Services (SW) Ltd | Administrative & support | 2020 |
| Classic Country Pubs Limited | Hospitality | 2025 |
| Classic Cure Limited | Construction | 1999 |
| Classic Taxi Ltd | Transport & logistics | 2020 |
| Classicrobust Limited | Wholesale & retail | 2024 |
| Classifi Limited | Professional & scientific | 2021 |
| Classified Document Publishing Ltd | Information & communication | 2021 |
| Classique Hair Studio Limited | Other services | 2005 |
| Classpass UK Limited | Information & communication | 2015 |