| Credere Resourcing Limited | Administrative & support | 2005 |
| Creflo Dollar Ministries | Other services | 1997 |
| Crematorium Company Limited(The) | Extraterritorial | 1914 |
| Crescent Living Ltd | Real estate | 2025 |
| Cressian Ltd | Wholesale & retail | 2025 |
| Crestmead Limited | Information & communication | 2025 |
| Crisium Ltd | Real estate | 2013 |
| Crisp Jones Consulting Ltd | Administrative & support | 2025 |
| Criterion Construction Ltd | Construction | 2025 |
| Critical CPA Limited | Administrative & support | 2000 |
| CRL Geoscience Ltd | Professional & scientific | 2024 |
| CRL Group Holdings Ltd | Other services | 2025 |
| Croft IT Services Limited | Information & communication | 2011 |
| Crompton Court Commercial Management Company Limited | Real estate | 2005 |
| Croninco Limited | Professional & scientific | 2018 |
| Crosswind Properties Ltd | Administrative & support | 2021 |
| Crow Kids Day Nursery Limited | Administrative & support | 2007 |
| Crowded Lunch Studios Limited | Information & communication | 2024 |
| Crown Construction (Midlands) Limited | Construction | 2021 |
| Crown Spaces Ltd | Real estate | 2019 |
| Crows Holdings Limited | Financial services | 2024 |
| Cruise Control Properties Ltd | Real estate | 2023 |
| Cruise Control Recruitment Ltd | Administrative & support | 2020 |
| Crutchley Capital Limited | Real estate | 2026 |
| Cryogas Services Limited | Professional & scientific | 2026 |
| Crypto Dragon's DEN Ltd | Information & communication | 2022 |
| Crystal Moon Wellness Ltd | Health & social care | 2025 |
| Crystalbest Enterprise Limited | Wholesale & retail | 2025 |
| CS Change Management Consultancy Limited | Professional & scientific | 2016 |
| CSK Maintenance Ltd | Administrative & support | 2017 |
| CSL Trading Limited | Wholesale & retail | 2013 |
| CT88 Ltd | Wholesale & retail | 2021 |
| CTA Industrial Ltd | Wholesale & retail | 2024 |
| Ctrl + V Productions Ltd | Information & communication | 2012 |
| Ctsecc Limited | Professional & scientific | 2017 |
| CU Global Supply Chain Limited | Wholesale & retail | 2017 |
| Cube Commercial (Global) Limited | Construction | 2023 |
| Cube Home Improvements Limited | Construction | 2010 |
| Cumbria Commercial Kitchens Limited | Wholesale & retail | 2020 |
| Cummins Civils Ltd | Agriculture & fishing | 2018 |
| CUP and String Communications Ltd | Administrative & support | 2015 |
| Cura Care Homes Ltd | Health & social care | 2023 |
| Curator Service Ltd | Professional & scientific | 2013 |
| Curdworth House Coffee Shop Limited | Hospitality | 2021 |
| Curdworth Kennels Ltd | Agriculture & fishing | 2016 |
| Curdworth Motor Company Ltd | Wholesale & retail | 2004 |
| Curious Alice Limited | Administrative & support | 2011 |
| Curious OD Limited | Professional & scientific | 2025 |
| Curve Design and Build Solutions Limited | Construction | 2010 |
| Custom Gates and Barriers Ltd | Administrative & support | 2025 |
| Customised for YOU Ltd | Wholesale & retail | 2022 |
| CV Toystore Limited | Wholesale & retail | 2017 |
| CW Services Roofing and Construction Ltd | Construction | 2025 |
| CW Surveying Limited | Professional & scientific | 2018 |
| CWF Associates Limited | Information & communication | 2019 |
| CWP Consultant( UK) Ltd | Other services | 2016 |
| CY UK Ltd | Transport & logistics | 2007 |
| Cyber Chain Alliance Ltd | Information & communication | 2018 |
| Cyber House Party CIC | Administrative & support | 2025 |
| Cybermind Technology Ltd | Information & communication | 2021 |
| Cybervise Ltd | Information & communication | 2019 |
| Cybotify Ltd | Hospitality | 2022 |
| Cydaf Technologies Ltd | Water & waste | 2012 |
| Cygnet Court Management Company Limited | Real estate | 2006 |
| CYP Properties Limited | Real estate | 2019 |
| Cypress Gardens Residents Association Limited | Households | 2002 |
| Cyprus Catering Supplies Limited | Wholesale & retail | 2008 |
| Cyril Charlesworth & Co. Limited | Professional & scientific | 1974 |
| Cyril H.Lovegrove Limited | Extraterritorial | 1951 |
| Cyrus Coins Limited | Financial services | 2024 |
| D & a Global Developments Ltd | Real estate | 2026 |
| D & a Specialcare Transport Ltd | Transport & logistics | 2024 |
| D & a Stays Ltd | Real estate | 2021 |
| D & C Lockhart (Holdings) Limited | Agriculture & fishing | 2015 |
| D & K Heating Services Limited | Administrative & support | 2004 |
| D Carter Consulting Limited | Professional & scientific | 2014 |
| D Davies Property Ltd | Households | 2024 |
| D I Films Limited | Information & communication | 2007 |
| D J Brunell Brickwork Limited | Construction | 2014 |
| D J Buckland & Sons Limited | Wholesale & retail | 2003 |
| D J Collectibles Ltd | Wholesale & retail | 2020 |
| D J Dunn Ltd | Administrative & support | 2022 |
| D J Peach Ltd | Construction | 2024 |
| D J Secure Ltd | Transport & logistics | 2015 |
| D J Thomas (Funeral Directors) Limited | Extraterritorial | 2003 |
| D L Jewellery Limited | Other services | 2011 |
| D L M Contracts Limited | Transport & logistics | 2016 |
| D W Morgan Fabrications Limited | Manufacturing | 1995 |
| D W Recruitment Ltd | Administrative & support | 2022 |
| D&C Insulations Limited | Construction | 2021 |
| D&D Eazy Haulage Ltd | Transport & logistics | 2024 |
| D&H Penguin Family Ltd | Wholesale & retail | 2024 |
| D&K and Sons Estates Limited | Real estate | 2019 |
| D. Walsh & SON Limited | Extraterritorial | 1961 |
| D.Barrie Risk Management Ltd | Administrative & support | 2001 |
| D.C.Turley Ltd | Professional & scientific | 2024 |
| D.E.B (GB) Limited | Professional & scientific | 2018 |
| D.J. Evans Forse & Co. Limited | Extraterritorial | 1972 |
| D.K.I (MED) Ltd | Health & social care | 2005 |
| D.S.D United Limited | Manufacturing | 2013 |