| Brana Investments Ltd | Real estate | 2020 |
| Brand Architekts Group Limited | Wholesale & retail | 1986 |
| Brave Environments Ltd | Professional & scientific | 2022 |
| Bray Court Residents Ltd | Households | 2020 |
| Bright Space Developments Ltd | Construction | 2026 |
| Brilliant Bright Cleaners Ltd | Administrative & support | 2021 |
| Brinsmoor Limited | Financial services | 2015 |
| Bromex Leisure Ltd | Hospitality | 2020 |
| Bromfield Precision Engineering Ltd. | Manufacturing | 2001 |
| Brooks&Royce Ltd | Wholesale & retail | 2024 |
| Brown Electrical Installation Ltd | Construction | 2024 |
| BRS Marketing Limited | Professional & scientific | 2015 |
| BS Limited | Transport & logistics | 2008 |
| BSC Investments Ltd | Real estate | 2022 |
| Buckinghamshire Landscapes Ltd | Administrative & support | 2025 |
| Buckland Assets Ltd | Real estate | 2025 |
| Budget Living Homes Ltd | Construction | 2026 |
| Buildout Construction Ltd | Construction | 2024 |
| Built by Gale Ltd | Construction | 2025 |
| Bula GAS Ltd | Construction | 2022 |
| Bullock & Bullock Limited | Professional & scientific | 2017 |
| Business Dezign.Com Limited | Information & communication | 1998 |
| Byron Properties SW Ltd | Real estate | 2022 |
| C. M. Realty LLP | | 2013 |
| C.M. Properties Investments Ltd. | Real estate | 2012 |
| CA Electrical Engineering Ltd. | Construction | 2016 |
| Ca&Ma IT Limited | Other services | 2009 |
| Cademy Football Club CIC | Arts & recreation | 2025 |
| Caffe DEL RE Ltd | Administrative & support | 2016 |
| Cambio Change Ltd | Professional & scientific | 2018 |
| Camcrete Limited | Manufacturing | 2017 |
| Cartel Decorators Ltd | Construction | 2023 |
| CEB Film and Construction Limited | Construction | 2019 |
| Cedar View Properties Ltd | Real estate | 2021 |
| Cedar View Property Ltd | Real estate | 2019 |
| Celsius Studio Limited | Arts & recreation | 2025 |
| Challenger Commercial Vehicle Bodywork Limited | Wholesale & retail | 2012 |
| Chamatkar Sandhu Ltd | Information & communication | 2025 |
| Changes Design Ltd | Information & communication | 2021 |
| Chanray Limited | Construction | 2024 |
| Cheesy Smiles Limited | Other services | 2014 |
| Cherry Tree Properties (Slough) Ltd. | Extraterritorial | 2010 |
| CHH Property Services Ltd | Construction | 2024 |
| Chiswick Rubbish Clearance London Ltd | Water & waste | 2024 |
| Church Lane Management Company (Chalfont ST Peter) Limited | Households | 1990 |
| City&Rural Electrics Limited | Manufacturing | 2025 |
| Cjjs Consulting Ltd | Professional & scientific | 2025 |
| Clarke Safety Services Ltd. | Administrative & support | 2015 |
| Class a Records Ltd | Information & communication | 2025 |
| Clean Vibes Ltd | Other services | 2019 |
| Clearway Investments Limited | Real estate | 2003 |
| Clickworks Online Ltd | Information & communication | 2022 |
| Client Scale Ltd | Professional & scientific | 2025 |
| CM Logistics Group Ltd | Education | 2023 |
| Cmfshop Ltd | Wholesale & retail | 2026 |
| Cmitra Consulting Ltd | Administrative & support | 2014 |
| Coach Displays Limited | Administrative & support | 1991 |
| Coco Bean Coffee Ltd | Hospitality | 2026 |
| Codelegs Ltd | Information & communication | 2011 |
| Colne Valley Honey Ltd | Agriculture & fishing | 2021 |
| Comms Union Ltd | Construction | 2026 |
| Compume Ltd | Information & communication | 2010 |
| Connect Fostering Services Ltd | Administrative & support | 2013 |
| Connect Group Holdings Ltd | Administrative & support | 2021 |
| Conscious International Ltd | Information & communication | 2023 |
| Constant Delivery Ltd | Transport & logistics | 2019 |
| Coraider Services Limited | Information & communication | 1995 |
| Core Companies Ltd | Wholesale & retail | 2010 |
| Core Maintenance Contracts Limited | Construction | 2021 |
| Coronado Estates UK Limited | Real estate | 2024 |
| Corventis Limited | Professional & scientific | 2005 |
| Cosmo Globe Ltd | Financial services | 2021 |
| Cquel Limited | Professional & scientific | 2017 |
| CR Grounds Maintenance Limited | Administrative & support | 2019 |
| Credit Mobilier Ltd | Administrative & support | 2016 |
| Crest Insurance Consultants Limited | Financial services | 1996 |
| Crisp Homes Ltd | Construction | 2022 |
| Crown Point Investments Ltd | Financial services | 2021 |
| Crystal Cleaners Iver Ltd | Other services | 2020 |
| Crystal Home Development Ltd | Construction | 2023 |
| Crystal Maze Properties Ltd | Real estate | 2026 |
| Culpepper (Wentworth) Limited | Construction | 2024 |
| Cyril's of Shepherds Bush Limited | Transport & logistics | 1960 |
| D & B Property Developers Ltd | Real estate | 2021 |
| D Lockey Limited | Health & social care | 2012 |
| D M Interiors Slough Limited | Construction | 2017 |
| D.A.R. 1969 Ltd | Transport & logistics | 2018 |
| D5 Inc Limited | Information & communication | 2017 |
| Dallas Estates Ltd | Real estate | 2024 |
| Damm Ltd | Professional & scientific | 2020 |
| Daniel Trans Sport Limited | Transport & logistics | 2019 |
| Danion AI Consulting Ltd | Information & communication | 2019 |
| Darcy's Bakery Ltd | Hospitality | 2026 |
| Dare to TRY Productions Ltd | Information & communication | 2023 |
| Dark Shadow Lighting Ltd | Construction | 2025 |
| Darshan Group Ltd | Hospitality | 2018 |
| Data Design Solutions Limited | Information & communication | 2011 |
| Dataforte Ltd | Information & communication | 2026 |
| Datchet Properties Limited | Real estate | 2001 |
| Dave (UK) Limited | Construction | 2014 |