| Cjfm Property Renovations Ltd | Construction | 2024 |
| CJK (Yorkshire) Limited | Real estate | 2019 |
| CJS Carpentry & Joinery Ltd | Construction | 2021 |
| CJS Logistics Ltd | Transport & logistics | 2017 |
| CJT Plumbing and HEATING123 Ltd | Construction | 2024 |
| CK09CAD Ltd | Arts & recreation | 2025 |
| CKL Property Ltd | Real estate | 2020 |
| CL Marsh Properties Ltd | Real estate | 2026 |
| CLA Trading Limited | Administrative & support | 2012 |
| Claim 500 Limited | Professional & scientific | 2008 |
| Claimdesk Limited | Professional & scientific | 2018 |
| Claimwise Legal Services Ltd. | Professional & scientific | 2005 |
| Claimwise Ltd | Administrative & support | 2018 |
| Claire E Taylor Limited | Other services | 2006 |
| Claire Meade Corporation Limited | Real estate | 2019 |
| Clamore Ltd | Wholesale & retail | 2025 |
| Clara Properties Ltd | Real estate | 2025 |
| Claremont Childrens Homes Ltd | Health & social care | 2026 |
| Claremont Community Trust Limited | Health & social care | 2003 |
| Claremont Neuro Consulting Ltd | Professional & scientific | 2025 |
| Claremont Solicitors Limited | Professional & scientific | 2018 |
| Clarence Road E17 Ltd | Real estate | 2024 |
| Clarendon Recruitment Limited | Administrative & support | 2023 |
| Claricent Data Ltd | Information & communication | 2017 |
| Clarify Clinical Limited | Health & social care | 2024 |
| Clarity Lead Solutions Limited | Professional & scientific | 2018 |
| Clarke-Adams Properties Limited | Real estate | 2022 |
| Clarus (UK) Ltd | Other services | 2012 |
| Clasping Hands Business Solutions Limited | Professional & scientific | 2014 |
| Class Docs Limited | Professional & scientific | 2024 |
| Class Dynamix Events | Health & social care | 2021 |
| Class Homes Ltd | Real estate | 2022 |
| Class One Meat & Poultry Limited | Manufacturing | 2021 |
| Classic Automobiles Limited | Wholesale & retail | 2015 |
| Classic Clean Ltd | Administrative & support | 2020 |
| Classic Homes (Yorkshire) Ltd | Real estate | 2024 |
| Classic Persian Restaurant (Bradford) Ltd | Hospitality | 2017 |
| Classic Persian Restaurant BFD Ltd | Hospitality | 2025 |
| Classic Renovations (Yorkshire) Ltd | Construction | 2023 |
| Classroom Staff Sickness Ltd | Financial services | 2018 |
| Classy Rose UK Ltd | Wholesale & retail | 2025 |
| Claughton Properties LLP | | 2024 |
| Clave Media Ltd | Professional & scientific | 2025 |
| Clay and TUN Coffee House Ltd | Hospitality | 2018 |
| Clayton Balti Ltd | Hospitality | 2021 |
| Clayton Best Kebab & Shake Limited | Hospitality | 2023 |
| Clayton Business Solutions Ltd | Professional & scientific | 2020 |
| Clayton Convenience Ltd | Wholesale & retail | 2025 |
| Clayton Dental Care Limited | Health & social care | 2017 |
| Clayton Farming Limited | Agriculture & fishing | 2020 |
| Clayton Garage Revamps Limited | Construction | 2014 |
| Clayton Groundworks Limited | Construction | 2011 |
| Clayton Hardware & DIY Ltd | Wholesale & retail | 2023 |
| Clayton Moorfield Holdings Limited | Real estate | 1968 |
| Clayton Portable Buildings Limited | Manufacturing | 1962 |
| Clayton Skincare Limited | Other services | 2021 |
| Clayton Tech Ltd | Wholesale & retail | 2026 |
| Clayton Tech Repairs Ltd | Other services | 2024 |
| Clayton Trimz Ltd | Other services | 2023 |
| Clayton Tunnel Limited | Real estate | 2005 |
| Clayton Wine Stores Limited | Wholesale & retail | 2022 |
| Claywood (Specialist Building Services) Limited | Construction | 2000 |
| CLB Porthmadog Limited | Hospitality | 2022 |
| CLB Productions Limited | Information & communication | 2023 |
| Cleage Clinic (Yorkshire) Ltd | Other services | 2025 |
| Clean and Connect Ltd | Administrative & support | 2026 |
| Clean Attire Limited | Administrative & support | 2021 |
| Clean Bites Deli Ltd | Hospitality | 2025 |
| Clean Drive Ltd | Wholesale & retail | 2022 |
| Clean Fit Windows & Doors Ltd | Construction | 2026 |
| Clean Healthy Hands Limited | Administrative & support | 2009 |
| Clean UP Your ACT Ltd | Administrative & support | 2025 |
| Cleancare Hygiene Limited | Administrative & support | 2019 |
| Cleancutlandscape Ltd | Professional & scientific | 2025 |
| Cleaning Line Ltd | Other services | 2018 |
| Cleaning Power Services Limited | Other services | 2006 |
| Cleanquest Solutions Ltd | Administrative & support | 2025 |
| Cleanse Comfort Limited | Administrative & support | 2026 |
| Cleanwalk Ltd | Other services | 2025 |
| Cleanwaze Ltd | Administrative & support | 2024 |
| Clear Cutz 2023 Ltd | Other services | 2023 |
| Clear Image Systems Limited | Construction | 1998 |
| Clear Skin Clinic Bradford Ltd | Other services | 2021 |
| Clear View Movable Walls Solutions Ltd | Construction | 2023 |
| Clear Water Property Developers Limited | Real estate | 2021 |
| Clearance Flooring BFD Ltd | Wholesale & retail | 2025 |
| Clearcite Limited | Administrative & support | 2012 |
| Clearell Ltd | Wholesale & retail | 2025 |
| Clearocean VA Ltd | Health & social care | 2019 |
| Clearpath Care Solutions Ltd | Health & social care | 2026 |
| Clearsafe Driving Ltd | Education | 2026 |
| Cleartrace Infection Control Limited | Administrative & support | 2022 |
| Clearview Access Ltd | Administrative & support | 2020 |
| Clearview Dental Clinic Limited | Health & social care | 2024 |
| Clearview General Services Ltd | Transport & logistics | 2025 |
| Clearview Installations and Systems Ltd | Construction | 2010 |
| Clearview Platinum Living Ltd | Real estate | 2025 |
| Clearview Surveillance Group Ltd | Construction | 2026 |
| Clearvista Analytics Ltd | Information & communication | 2024 |
| Clearvue Optical Limited | Wholesale & retail | 2014 |