| Clarke Richardson Fabrications Ltd | Manufacturing | 2002 |
| Clarke Rowe Solicitors Limited | Professional & scientific | 2011 |
| Clarks Landscapes Limited | Administrative & support | 2003 |
| Clarst Limited | Health & social care | 2016 |
| Class Contractors Ltd | Construction | 2018 |
| Class of London Teaching Ltd | Education | 2019 |
| Classic Fuel Solutions Ltd | Extraterritorial | 2022 |
| Classic Global Ltd | Construction | 2026 |
| Classic Vegan Limited | Wholesale & retail | 2018 |
| Classiche Limited | Wholesale & retail | 2025 |
| Classroom Companion Ltd | Education | 2025 |
| Classroom Hubs Ltd | Hospitality | 2018 |
| Clavell Management Company Limited | Households | 2022 |
| Clayfield Studios Ltd | Professional & scientific | 2020 |
| Clayman Electronics Limited | Construction | 1986 |
| Clayson Capital Partners Limited | Financial services | 2006 |
| Clayton Engineering Limited | Manufacturing | 1976 |
| Cleals Holdings Limited | Financial services | 2019 |
| Cleals Property Management Ltd | Administrative & support | 2018 |
| Clean Beauty LAB Limited | Wholesale & retail | 2022 |
| Clean CUT Carpentry Southern Limited | Construction | 2024 |
| Clean Mean Data Group Ltd | Information & communication | 2026 |
| Clean Ovens Domestic Limited | Administrative & support | 2008 |
| Cleaner Air Systems Limited | Other services | 2018 |
| Clear Audit Solutions Limited | Professional & scientific | 2024 |
| Clear Brew Bournemouth Ltd | Administrative & support | 2023 |
| Clear Building Management Limited | Administrative & support | 2015 |
| Clear Crown Ltd | Information & communication | 2015 |
| CLEAR2CONNECT Ltd | Information & communication | 2025 |
| Clearbrook Management Consultancy Limited | Professional & scientific | 2016 |
| Clearhold Property Group Ltd | Households | 2026 |
| Cleartelecomus Ltd | Information & communication | 2013 |
| Clearwater Dynamics Ltd. | Transport & logistics | 2014 |
| Clearwater Real Estate Limited | Real estate | 2003 |
| Clearwater Tracking Limited | Extraterritorial | 2018 |
| Clearway Franchising Limited | Administrative & support | 2022 |
| Clearway Pools Limited | Wholesale & retail | 2008 |
| Cledgra Ltd | Wholesale & retail | 2025 |
| Clemdell Limited | Real estate | 1990 |
| Clerica AI Ltd | Information & communication | 2025 |
| Clever Comerce Ltd | Wholesale & retail | 2025 |
| Clever Keys Ltd | Real estate | 2023 |
| Clevertronics Limited | Extraterritorial | 2014 |
| Click Pilot PPC Ltd | Professional & scientific | 2025 |
| Clicklifestyle Ltd | Wholesale & retail | 2023 |
| Clickscart Ltd | Wholesale & retail | 2025 |
| Client Accounting Limited | Professional & scientific | 1999 |
| Client Bridge Limited | Information & communication | 2012 |
| Client Connect by Flora Ltd | Professional & scientific | 2024 |
| Clifden Arms Holding Co Ltd | Financial services | 2018 |
| Cliff House (Bournemouth) Management Limited | Households | 1998 |
| Clifton Lodge Bournemouth Limited | Households | 1989 |
| Clifton Medical Limited | Health & social care | 2022 |
| Climanova Ltd | Professional & scientific | 2025 |
| Climb Above Limited | Professional & scientific | 2024 |
| Clinch-It Ltd | Manufacturing | 2021 |
| Clinkard Ltd | Wholesale & retail | 2004 |
| Clipstone Develco 1 Limited | Construction | 2022 |
| Clique Leisure Limited | Information & communication | 2018 |
| Clive Grout Management Consultancy Ltd | Professional & scientific | 2009 |
| Clive Spendley Kitchen Fitting Services Limited | Construction | 2026 |
| Cliveden Property Management Limited | Administrative & support | 2020 |
| Clixeo Media Limited | Information & communication | 2020 |
| CLKSL123 Ltd | Public administration | 2021 |
| Clobie Enterprise Limited | Wholesale & retail | 2023 |
| Clockcrow Limited | Information & communication | 2024 |
| CLOCKWORX21 Ltd | Professional & scientific | 2021 |
| Cloco Official Ltd | Wholesale & retail | 2026 |
| Cloud 9 Accounting Solutions Ltd | Professional & scientific | 2020 |
| Cloud Business Enterprise Ltd | Information & communication | 2023 |
| Cloud Cart Ltd | Wholesale & retail | 2026 |
| Cloud Devandops Ltd | Information & communication | 2020 |
| Cloud Digital Group Ltd | Information & communication | 2021 |
| Cloud Innovation Limited | Information & communication | 2018 |
| Cloud Residential Holdings Ltd | Real estate | 2023 |
| Cloud Spares Ltd | Manufacturing | 2025 |
| Cloud Support Services Ltd | Information & communication | 2021 |
| Cloud Town Market Ltd | Wholesale & retail | 2026 |
| Cloudbreak Group Limited | Public administration | 2025 |
| Cloudforce Innovations Investments Limited | Information & communication | 2024 |
| Cloudserve Ltd | Information & communication | 2009 |
| Clover Drive Management Limited | Households | 2004 |
| Clow Specialist Structural Waterproofing Ltd | Construction | 2026 |
| Clrd Technologies Ltd | Information & communication | 2026 |
| Club 11 Plus Ltd | Education | 2024 |
| Club BH15 Ltd | Hospitality | 2026 |
| Club Kings Official Ltd | Wholesale & retail | 2023 |
| Clubhub Poole Ltd | Other services | 2020 |
| Clubpilot Limited | Information & communication | 2025 |
| Cluster Infotech Limited | Information & communication | 2024 |
| CM Croydon Ltd | Hospitality | 2022 |
| Cmbw Holdings Limited | Financial services | 2025 |
| CMC Marine Limited | Manufacturing | 2018 |
| CMC Music Limited | Information & communication | 2025 |
| CMD Team Ltd | Construction | 2025 |
| Cmd-Ctrl Design Limited | Information & communication | 2012 |
| Cmlt Ltd | Wholesale & retail | 2024 |
| CMP (UK) Limited | Manufacturing | 1994 |
| CMQ Ltd | Information & communication | 2022 |
| CMS Housing Consultancy Ltd | Professional & scientific | 2025 |