| Ckad Consul Limited | Health & social care | 2021 |
| CKB Holdings Limited | Hospitality | 2025 |
| CKD Care and Support Consultancy Ltd | Professional & scientific | 2024 |
| CKH Ground Works Ltd | Construction | 2020 |
| CKJ Site Services Limited | Professional & scientific | 2020 |
| Ckpm Limited | Professional & scientific | 2009 |
| Cktm Care Ltd | Health & social care | 2022 |
| CL Civils & Formwork Ltd | Construction | 2018 |
| CL Futures Ltd | Households | 2025 |
| CL Train Rider Ltd | Manufacturing | 2026 |
| Cl:Ex Limited | Administrative & support | 2005 |
| CLA Auto Limited | Wholesale & retail | 2024 |
| CLA Inns Ltd | Hospitality | 2020 |
| Clad Line Limited | Households | 2015 |
| Cladam Holdings Ltd | Financial services | 2026 |
| Cladam Nottingham Ltd | Real estate | 2026 |
| Cladceil Limited | Construction | 1986 |
| Cladit Design Limited | Construction | 2007 |
| Clair Fashions Limited | Wholesale & retail | 2013 |
| Claire Bowmar Osteopathy Limited | Health & social care | 2015 |
| Claire Evans Accountancy Services Limited | Professional & scientific | 2002 |
| Clandeboye Ltd | Arts & recreation | 2019 |
| Clapham Common VE Limited | Other services | 2011 |
| Clare Morris (U K) Limited | | 1982 |
| Clare Thompson Nutrition Limited | Health & social care | 2022 |
| Clarefield Holdings Ltd | Construction | 2024 |
| Claregrange Care Homes Limited | Extraterritorial | 2004 |
| Claregrange Limited | Real estate | 1987 |
| Claregrange Nottingham Lettings Limited | Real estate | 2009 |
| Claregrange Property Services Limited | Extraterritorial | 2004 |
| Claremont (Nottingham) Limited | Real estate | 1982 |
| Claremont Anaesthetists Limited | Health & social care | 2013 |
| Claremont House Property Limited | Construction | 2014 |
| Clarence Marina Limited | Arts & recreation | 2006 |
| Clarence Properties (Nottingham) Limited | Administrative & support | 2018 |
| Clarendon Court (Nottingham) Limited | Health & social care | 2017 |
| Clarendon Court (Nottingham) Management Company Limited | Households | 1989 |
| Clarendon Court Freehold and Management Company Limited | Real estate | 2007 |
| Clarendon House (Nottingham) Management Company Limited | Real estate | 2005 |
| Clarendon Land & Development II Ltd | Real estate | 2023 |
| Clarendon Land & Development Ltd | Real estate | 2018 |
| Clarendon Park Solutions Limited | Professional & scientific | 2016 |
| Clarendon Residential Limited | Hospitality | 2026 |
| Clarico Estates Limited | Real estate | 2025 |
| Clarico Healthcare Limited | Public administration | 2025 |
| Clarion I. Ltd | Professional & scientific | 2018 |
| Clarion Media Ltd | Other services | 2019 |
| Clarion Mount Ltd | Wholesale & retail | 2024 |
| Claris Healthcare Ltd | Health & social care | 2014 |
| Clarity 4 Food Limited | Manufacturing | 2014 |
| Clarity Businesses Ltd | Professional & scientific | 2017 |
| Clarity Homecare (Direct) Ltd | Health & social care | 2018 |
| Clarity IT Solutions Limited | Information & communication | 2000 |
| Clarity Optical Limited | Manufacturing | 2018 |
| Clarity:Ns Ltd | Professional & scientific | 2004 |
| Clark & SON Investments Limited | Real estate | 2020 |
| Clark Bioinsights Ltd | Professional & scientific | 2026 |
| Clark Building & Installation Services Limited | Construction | 2020 |
| Clark Flooring Company Limited | Wholesale & retail | 2016 |
| Clark LET Limited | Real estate | 2022 |
| Clark Special Projects Ltd | Professional & scientific | 2019 |
| Clarke & Co Hockey Clinics Limited | Extraterritorial | 2023 |
| Clarke & Co Hockey Limited | Education | 2018 |
| Clarke & Powell Limited | Construction | 2006 |
| Clarke Agri Services Limited | Agriculture & fishing | 2015 |
| Clarke Dove (Insurance Brokers) Limited | Financial services | 1982 |
| Clarke Dove Management Company Limited | Professional & scientific | 2006 |
| Clarke Elevators Ltd | Professional & scientific | 2021 |
| Clarke Farms Limited | Agriculture & fishing | 2007 |
| Clarke Holdings Limited | Real estate | 1988 |
| Clarke House Care Ltd | Public administration | 2018 |
| Clarke Jones Developments Ltd | Real estate | 2019 |
| Clarke K Limited | Information & communication | 2025 |
| Clarke Residential Investments Limited | Real estate | 2026 |
| Clarke's Congeries Limited | Construction | 2018 |
| Clarkes Care Home Limited | Health & social care | 2026 |
| Clarkes Kitchens and Bedrooms Limited | Wholesale & retail | 2006 |
| Clarkes PUB Co Limited | Hospitality | 2012 |
| Clarusblue Consulting Limited | Professional & scientific | 2015 |
| Clarx Scaffolding Ltd | Construction | 2026 |
| Class 20189 Limited | Transport & logistics | 2006 |
| Classic (Nottingham) Limited | Wholesale & retail | 2012 |
| Classic and Vintage Vehicle Hire Ltd | Other services | 2017 |
| Classic Automotive and Custom EV Tech Specialist Ltd | Wholesale & retail | 2026 |
| Classic Cleaning Solutions Ltd | Administrative & support | 2023 |
| Classic Cuisine of Northampton Limited | Manufacturing | 2008 |
| Classic Lines Plus Signs Limited | Manufacturing | 2011 |
| Classic Plates Limited | Manufacturing | 2022 |
| Classic Rewinds Limited | Extraterritorial | 1963 |
| Classic Solutions (Central) Limited | Administrative & support | 2018 |
| CLASSIC77 Ltd | Wholesale & retail | 2019 |
| Classics Storage Limited | Transport & logistics | 2023 |
| Classique Skyn Ltd | Other services | 2025 |
| Classroom Recruiters Limited | Administrative & support | 2023 |
| Classy Clean MK Ltd | Administrative & support | 2025 |
| Classy Short Stays Ltd | Hospitality | 2023 |
| Clatons Agency Ltd | Administrative & support | 2018 |
| Clatons Ltd | Wholesale & retail | 2016 |
| Clatons Security Ltd | Administrative & support | 2017 |
| Claudia Cleaning Services Limited | Administrative & support | 2026 |