| CSI Commercial Properties LLP | | 2009 |
| CSI Global Ltd | Information & communication | 2011 |
| CSI Properties Limited | Real estate | 2003 |
| CSJ PR & Marketing Ltd | Professional & scientific | 2022 |
| Csls Property Limited | Real estate | 2024 |
| CSN Building Contractors Ltd | Construction | 2020 |
| Csnapit Limited | Information & communication | 2023 |
| Csph Coverplans Limited | Professional & scientific | 2020 |
| CSR Electrical Limited | Construction | 2007 |
| CSR Host Consulting Ltd | Professional & scientific | 2017 |
| CSS Isotek Limited | Manufacturing | 2010 |
| CSS Leeds Limited | Manufacturing | 2015 |
| Csskhs Ltd | Wholesale & retail | 2023 |
| CST Cleaning Services Limited | Administrative & support | 2025 |
| Cstfyn Ltd | Transport & logistics | 2025 |
| Cstj Property Limited | Real estate | 2016 |
| CSUR01 Ltd | Information & communication | 2014 |
| CSUR02 Ltd | Manufacturing | 2014 |
| CSUR03 Ltd | Construction | 2021 |
| CSUR04 Ltd | Professional & scientific | 2013 |
| CSW Holdings (North) Limited | Financial services | 2025 |
| CSW Property Investments Ltd | Real estate | 2021 |
| CSY Holdings Limited | Construction | 2017 |
| CT Ackworth Ltd | Hospitality | 2020 |
| CT Civil Engineering Limited | Construction | 2016 |
| CT Dental Services Limited | Health & social care | 2021 |
| CT Finance Ltd | Professional & scientific | 2024 |
| CT Joinery and Developments Ltd | Construction | 2022 |
| CT Pontefract Ltd | Hospitality | 2022 |
| CT Surveys Holdings Limited | Financial services | 2023 |
| CT Surveys Limited | Construction | 2004 |
| CT Whitwood Ltd | Hospitality | 2024 |
| Ct&C Ltd | Administrative & support | 2018 |
| CT10 Ltd | Real estate | 2014 |
| CT22 Storage Limited | Transport & logistics | 2025 |
| CT33 Limited | Education | 2014 |
| CTA (Leeds) Ltd | Professional & scientific | 2007 |
| CTB Limited | Professional & scientific | 2008 |
| CTC Creative Comms Ltd | Information & communication | 2020 |
| CTC Digital Ltd | Professional & scientific | 2026 |
| Ctci Limited | Manufacturing | 2013 |
| CTJ Property LLP | | 2022 |
| CTK CC Ltd | Hospitality | 2017 |
| CTK Solutions Ltd | Real estate | 2021 |
| CTL 247 Limited | Transport & logistics | 2024 |
| CTL Care Solutions Ltd | Health & social care | 2021 |
| CTL Haulage Ltd | Transport & logistics | 2021 |
| Ctlsb Limited | Professional & scientific | 2020 |
| Ctlt Holdings Limited | Construction | 2023 |
| CTN Logistics Ltd | Transport & logistics | 2026 |
| Ctnaija Entertainment Ltd | Information & communication | 2023 |
| Ctrack Eastern Europe Holdings Ltd | Transport & logistics | 2011 |
| Ctrack Europe Holdings Ltd | Transport & logistics | 2011 |
| Ctrack International Holdings Ltd | Transport & logistics | 2011 |
| Ctrack Telematics Ltd | Transport & logistics | 2003 |
| Ctrack UK Limited | Transport & logistics | 2010 |
| CTS Emporium Ltd | Construction | 2015 |
| CTS Nucleus Limited | Information & communication | 2022 |
| CTS Properties Yorkshire Ltd | Real estate | 2024 |
| Ctuk Investments Limited | Real estate | 2025 |
| CTW Clothing Limited | Wholesale & retail | 2025 |
| CTX Consulting Ltd | Information & communication | 2025 |
| Cubby Studio Limited | Professional & scientific | 2019 |
| Cube AX Limited | Professional & scientific | 2019 |
| Cube Care Plus Limited | Administrative & support | 2020 |
| Cube Communications Limited | Administrative & support | 2010 |
| Cube Electrical Services Limited | Construction | 2000 |
| Cube KIT Ltd | Professional & scientific | 2025 |
| Cube Learning and Development Limited | Administrative & support | 2008 |
| Cube Logistics Limited | Transport & logistics | 2016 |
| Cube Security Limited | Administrative & support | 2004 |
| Cube Ventures (Leeds) Limited | Health & social care | 2021 |
| Cubed Property Group Ltd | Professional & scientific | 2019 |
| Cubic GAS Ltd | Construction | 2021 |
| Cubic Rentals Limited | Extraterritorial | 2021 |
| Cubicsoft Labs Ltd | Information & communication | 2024 |
| Cubihome Ltd | Construction | 2016 |
| Cubitus Company Ltd | Professional & scientific | 2019 |
| Cubs Consultancy Ltd | Professional & scientific | 2026 |
| Cuckoo Leeds Limited | Hospitality | 2017 |
| Cucumber Health Ltd | Health & social care | 2022 |
| Cueiq Ltd | Information & communication | 2023 |
| Cugras Properties UK Ltd | Real estate | 2025 |
| CUK Realisations Limited | Manufacturing | 1971 |
| Culco Ltd | Professional & scientific | 2022 |
| Cullen Industries Ltd | Professional & scientific | 2013 |
| Culligan Leisure Ltd | Hospitality | 2018 |
| Culligans Caravans Ltd | Wholesale & retail | 2021 |
| Culloden View Richmond Owners Limited | Households | 1989 |
| Cult Azure Ltd | Wholesale & retail | 2019 |
| Cultivaterx Ltd | Health & social care | 2026 |
| Cultural Arts Heritage Circle (the Circle) Limited | Professional & scientific | 2019 |
| Cultural Community Solutions Limited | Administrative & support | 2008 |
| Culture Change Works Ltd | Professional & scientific | 2024 |
| Culture of Excellence Ltd | Professional & scientific | 2020 |
| Cumberland (10) Limited | Real estate | 2019 |
| Cumberland (8) Limited | Financial services | 2023 |
| Cumberland (9) Limited | Real estate | 2014 |
| Cumberland House (Leeds) Management Company Limited | Real estate | 2014 |
| Cumberland Investments Limited | Financial services | 2016 |