| Crunch Box 786 Limited | Hospitality | 2025 |
| Crushed Silk Limited | Extraterritorial | 2024 |
| Cruze Chauffeur & Concierge Ltd | Administrative & support | 2025 |
| Cryoelectrical Ltd | Professional & scientific | 2024 |
| Cryohub Bedford Ltd | Other services | 2021 |
| Crystal Clear (Bedford) Ltd | Administrative & support | 2021 |
| Crystal Clear Industrial Cleaners Ltd | Administrative & support | 2010 |
| Crystal Core Solutions Ltd | Construction | 2026 |
| Crystal Smile Teeth Whitening Ltd | Other services | 2016 |
| Crystal Treasures Ltd | Manufacturing | 2024 |
| CS Events Wifi Ltd | Administrative & support | 2024 |
| CS Newco Holdings Limited | Financial services | 2020 |
| CSC Europe Limited | Professional & scientific | 2010 |
| CSC International Properties Limited | Real estate | 2025 |
| CSC Services UK Ltd | Transport & logistics | 2017 |
| CSK Direct Limited | Wholesale & retail | 2021 |
| CSM Carpentry & SON Ltd | Manufacturing | 2019 |
| CSM Group Ltd | Construction | 2024 |
| CSMNZ2 Ltd | Health & social care | 2025 |
| Cssw.London Limited | Construction | 2016 |
| CT and Events Ltd | Hospitality | 2025 |
| CT Interests Ltd | Wholesale & retail | 2024 |
| CT3 Services Ltd | Manufacturing | 2024 |
| CTB Plumbing and Heating Ltd | Construction | 2024 |
| CTB Property Services Limited | Administrative & support | 2017 |
| Ctll Ltd | Construction | 2018 |
| CTM Systems Limited | Professional & scientific | 1992 |
| CTM Systems Trustees Limited | Administrative & support | 2024 |
| CTM96 Property Ltd | Real estate | 2025 |
| CTW Trade Ltd | Wholesale & retail | 2016 |
| CTX Labs Limited | Information & communication | 2026 |
| Cubana HBJ Limited | Hospitality | 2023 |
| Cube Building Consultancy Limited | Professional & scientific | 2004 |
| Cuchhadia Ltd | Wholesale & retail | 2014 |
| CUE2CUE Limited | Professional & scientific | 2013 |
| Cultural Infrastructure Limited | Wholesale & retail | 1998 |
| Culver House RTM Company Limited | Real estate | 2016 |
| Cura Health MK Ltd | Health & social care | 2026 |
| Curly Kitchen Ltd | Hospitality | 2026 |
| Curly Sisters Catering Company Ltd | Hospitality | 2022 |
| Curryleaf Solutions Limited | Information & communication | 2009 |
| Custodial Management Solutions Ltd | Financial services | 2018 |
| Custom Car Audio Ltd | Manufacturing | 2021 |
| Custom Construction Ltd | Construction | 2022 |
| Custom Print Solutions Ltd | Manufacturing | 2024 |
| Custom Renewable Solutions Ltd | Construction | 2023 |
| Customer First Business Solutions Ltd | Information & communication | 2005 |
| Customised Stuff Ltd | Wholesale & retail | 2021 |
| CUT 'N' Collar Limited | Other services | 2018 |
| Cutting Corner Bletchley Limited | Other services | 2003 |
| Cutting Corner Winslow Limited | Other services | 2012 |
| Cutture Limited | Manufacturing | 2009 |
| CVF Advisory Ltd | Professional & scientific | 2026 |
| CVL Properties Ltd | Real estate | 2006 |
| Cvrg Ltd | Administrative & support | 2019 |
| CW Birmingham Limited | Arts & recreation | 2021 |
| CWC HR Ltd | Administrative & support | 2022 |
| CX Optimisation Ltd | Professional & scientific | 2021 |
| CXM Global Services Limited | Information & communication | 2025 |
| CXO Assist Limited | Information & communication | 2017 |
| CY Gregory Fitness Ltd | Other services | 2024 |
| CY Holdings Limited | Professional & scientific | 2017 |
| Cybel Management Limited | Administrative & support | 2016 |
| Cybertech Recruitment Ltd | Administrative & support | 2026 |
| Cyclone Systems Ltd | Professional & scientific | 2018 |
| Cygan Property Ltd | Construction | 2026 |
| Cylinder 5 Limited | Wholesale & retail | 2025 |
| Cymbeline Court Management Company Limited | Households | 1995 |
| Cynergilink Investment Ltd | Financial services | 2018 |
| Cynosure Solutions Limited | Information & communication | 2009 |
| CYP & Truck Ltd | Transport & logistics | 2015 |
| D & D Bakery Ltd | Manufacturing | 2009 |
| D & G Carpentry (Midlands) Limited | Construction | 2016 |
| D & G Noble Limited | Transport & logistics | 2003 |
| D & G Short Ltd | Administrative & support | 2019 |
| D & J Carpentry Limited | Construction | 2003 |
| D & R Restaurants Ltd | Hospitality | 2023 |
| D & S Meats Ltd | Wholesale & retail | 2009 |
| D & T Accountancy Ltd | Professional & scientific | 2020 |
| D and D Private Limited | Health & social care | 2019 |
| D and G Ayre Electrical Ltd | Construction | 2005 |
| D and M Trading Limited | Wholesale & retail | 2025 |
| D B Ground & Garden Ltd | Administrative & support | 2014 |
| D C Capital Ltd | Wholesale & retail | 2023 |
| D C M (Bedford) Limited | Construction | 2020 |
| D Ford (Electrical) Limited | Construction | 2011 |
| D Gelato Limited | Hospitality | 2021 |
| D Gibbs Carpentry Limited | Construction | 2008 |
| D Gill Homes Ltd | Real estate | 2019 |
| D Hall Cleaning Ltd | Administrative & support | 2014 |
| D J Mortgage Services Ltd | Financial services | 2014 |
| D J Sawford Limited | Financial services | 2015 |
| D J Solutions Ltd | Real estate | 2023 |
| D James Plumbing and Heating Limited | Construction | 2018 |
| D K P Developments Ltd | Construction | 2011 |
| D K Roofing and Construction (UK) Ltd | Construction | 2024 |
| D M Management Support Limited | Professional & scientific | 2023 |
| D N Delivery Services Limited | Transport & logistics | 2009 |
| D R Barbers Limited | Other services | 2011 |
| D R Consultants Ltd | Professional & scientific | 2024 |