| CTO Property Ltd | Real estate | 2018 |
| Ctrl-Technology Ltd | Professional & scientific | 2025 |
| Ctxt Consultancy Ltd | Professional & scientific | 2024 |
| Cumberland (11) Limited | Health & social care | 2020 |
| Cumberland (12) Limited | Health & social care | 2020 |
| Cumberland (5) Limited | Financial services | 2022 |
| Cumberland (6) Limited | Health & social care | 2021 |
| Cumberland Midco Limited | Health & social care | 2021 |
| Curarus Limited | Financial services | 2019 |
| Curious Comb Ltd | Other services | 2024 |
| Curious Magpie Ltd | Wholesale & retail | 2025 |
| Curious Percy Limited | Hospitality | 2026 |
| Currithers Property Ltd | Real estate | 2022 |
| Curry House (Clifton) Ltd | Hospitality | 2024 |
| Currylicious Limited | Hospitality | 2025 |
| Custom Apocalypse Ltd | Wholesale & retail | 2021 |
| Custom Car Paint Ltd | Wholesale & retail | 2024 |
| Custom Classic & Retro Limited | Other services | 2008 |
| Custom Conservatories (Leicester) Ltd | Construction | 2006 |
| Custom Construction (Leicester) Ltd | Construction | 2023 |
| Custom Supplements Limited | Manufacturing | 2022 |
| Custom VET Products Limited | Manufacturing | 2007 |
| Customvp Holdings Limited | Financial services | 2022 |
| Cutmore Events Ltd | Administrative & support | 2025 |
| Cutting Edge Hair Design (Loughborough) Ltd | Other services | 2012 |
| Cuttlefish Multimedia Ltd | Information & communication | 2005 |
| CV Plumbing Ltd | Construction | 2025 |
| CVC Cleaning Services LLP | | 2008 |
| CVC Contracts LLP | | 2013 |
| CVR Broadcast Ltd | Information & communication | 2026 |
| CWH Trading Limited | Wholesale & retail | 2011 |
| CWS Agency Limited | Professional & scientific | 2016 |
| CWY Solutions Limited | Administrative & support | 2013 |
| CXH Estates Ltd | Real estate | 2025 |
| Cybernetic Software Limited | Information & communication | 2026 |
| Cybpro Ltd | Information & communication | 2018 |
| Cycles of Change Acupuncture Limited | Other services | 2002 |
| Cycling Ally Ltd | Wholesale & retail | 2020 |
| Cyferd (UK) Ltd | Information & communication | 2024 |
| Cythergy Limited | Professional & scientific | 2025 |
| D & H Performance Limited | Administrative & support | 2024 |
| D & R Body Repairs Ltd | Other services | 2007 |
| D a Equine Limited | Professional & scientific | 2011 |
| D and J Kirton Limited | Manufacturing | 2015 |
| D G S (Ireland) Limited | Wholesale & retail | 2000 |
| D Hawe & Sons Limited | Administrative & support | 2023 |
| D James Holdings Limited | Administrative & support | 2007 |
| D P Sports Ltd | Wholesale & retail | 2023 |
| D R Emerson Ltd | Transport & logistics | 2024 |
| D R Extrusion Technology Limited | Manufacturing | 2014 |
| D R Hall Property Limited | Professional & scientific | 2014 |
| D S Installations Limited | Manufacturing | 2003 |
| D Screaton Property Services Limited | Construction | 2026 |
| D Shanks Plumbing & Heating Ltd | Construction | 2015 |
| D&A Luxury Living Limited | Real estate | 2026 |
| D&J IT Solutions Ltd | Information & communication | 2018 |
| D&Mm Property Ltd | Real estate | 2025 |
| D&P Pharma Holdings Ltd | Financial services | 2026 |
| D-Bap Limited | Real estate | 2025 |
| D-Jam Limited | Construction | 2019 |
| D. Heald Electrical Ltd | Construction | 2013 |
| D. Parmar Limited | Wholesale & retail | 2006 |
| D.A.R Consultancy (Loughborough) Limited | Professional & scientific | 2017 |
| D.G.S. Hardware Limited | Manufacturing | 1983 |
| D.T. & Sons Limited | Transport & logistics | 2024 |
| D10 Solutions Ltd | Information & communication | 2008 |
| D22 Networks Limited | Information & communication | 2021 |
| D365 Planning Limited | Information & communication | 2023 |
| DA AG (GB) Real Estate Ltd | Real estate | 2017 |
| DAB Online Services Ltd | Information & communication | 2024 |
| Dada Estates Ltd | Real estate | 2025 |
| Dagri Worldwide Solutions Limited | Professional & scientific | 2016 |
| Daisy and Rose Pubco Ltd | Hospitality | 2019 |
| Daisy's Digs Limited | Real estate | 2022 |
| Dale Consultants Ltd | Professional & scientific | 2024 |
| Dale Penney Furniture Limited | Manufacturing | 2003 |
| Dalhusky LLP | | 2013 |
| Daly Communications Limited | Extraterritorial | 2000 |
| Daly Telecom Limited | Information & communication | 1988 |
| Dalycom Limited | Extraterritorial | 2009 |
| Damian John Witty Ltd | Information & communication | 2009 |
| DAN Lawrence Limited | Professional & scientific | 2014 |
| Danaher & Walsh (Civil Engineering) Limited | Construction | 2000 |
| Danaher & Walsh Group Limited | Construction | 2000 |
| Danatrol Engineering Limited | Manufacturing | 1986 |
| Dangan Interactive Ltd | Information & communication | 2019 |
| Daniel Lewis Hairdressing Ltd | Other services | 2020 |
| Danielle's Mobile Mechanics Ltd | Wholesale & retail | 2018 |
| Danny Green Photography Limited | Professional & scientific | 2014 |
| Dannysan Limited | Wholesale & retail | 2012 |
| Darar Enterprises Ltd | Administrative & support | 2018 |
| Darby Bryer Limited | Wholesale & retail | 2026 |
| Dari Transport Ltd | Transport & logistics | 2025 |
| Dark Rock Software Ltd | Information & communication | 2021 |
| Darke Driver Hire Ltd | Transport & logistics | 2018 |
| Darlet Holdings Ltd | Financial services | 2025 |
| Darts Players Support Agency Ltd | Arts & recreation | 2026 |
| Darwin Bidco Limited | Professional & scientific | 2016 |
| Darwin Holdco Limited | Professional & scientific | 2016 |
| Darwin Midco Limited | Professional & scientific | 2016 |