| Bruhati Ventures Ltd | Real estate | 2017 |
| Brunel Business Centre Limited | Construction | 2025 |
| Brunel Capital Limited | Real estate | 2022 |
| Brunel House Estates Limited | Real estate | 2022 |
| Brunel Pharm Limited | Wholesale & retail | 2009 |
| Brutal Beasting Fitness Ltd | Other services | 2025 |
| Bryant Hall Todd Wealth Management Limited | Financial services | 2020 |
| BS Maidenhead Ltd | Hospitality | 2019 |
| BSC Supplies Ltd | Wholesale & retail | 2016 |
| BSD Mgmt Ltd | Professional & scientific | 2026 |
| BSS Construction and Groundwork Ltd | Construction | 2025 |
| BTJ News Private Limited | Information & communication | 2026 |
| BTM FIC Limited | Financial services | 2025 |
| Btsi Ltd | Information & communication | 2012 |
| Bubble Cat Toys Limited | Wholesale & retail | 2008 |
| Buckhaus Ltd | Wholesale & retail | 2025 |
| Bucks & Berks Plumbing and Heating Ltd | Other services | 2021 |
| Build Berg Limited | Real estate | 2017 |
| Build Partnership Group Limited | Financial services | 2025 |
| Build Partnership Materials Ltd | Wholesale & retail | 2025 |
| Builder Andrew Services Ltd | Construction | 2024 |
| Building Energy Services Group Limited | Administrative & support | 2015 |
| Building Logic (UK) Limited | Professional & scientific | 2009 |
| Building Management Solutions Integrators Limited | Construction | 1998 |
| Building Skills Ltd | Education | 2026 |
| Buildout Designs Limited | Construction | 2025 |
| Buildwise Construction & Maintenance Ltd | Construction | 2020 |
| Bulkhead Properties Limited | Professional & scientific | 1964 |
| Bumper Homes Limited | Wholesale & retail | 1982 |
| Bundawear Ltd | Wholesale & retail | 2025 |
| Bungalow Residence Association Limited | Households | 1993 |
| Burley Communications Limited | Administrative & support | 2013 |
| Burnelarch Limited | Wholesale & retail | 2025 |
| Burnham Court Freehold Limited | Real estate | 2019 |
| Burnham Estates Limited | Real estate | 2012 |
| Burnham Homes Ltd | Real estate | 2017 |
| Burnham Mews Management Company Limited | Households | 2007 |
| Burnham Plant Hire Limited | Administrative & support | 1991 |
| Burton's Plumbing & Heating Limited | Construction | 2012 |
| Buscot Green Limited | Professional & scientific | 2018 |
| Buscot Property Limited | Real estate | 2016 |
| Business Administration Support Ltd | Professional & scientific | 2021 |
| Business Class Yogi Consulting Ltd | Professional & scientific | 2014 |
| Business Continuity Centres Limited | Extraterritorial | 2003 |
| Business Integrated Governance CIC | Information & communication | 2021 |
| Business Partnership Services Limited | Administrative & support | 2004 |
| Business Technical Support Ltd | Other services | 2016 |
| Business Transformation Coaching Company Ltd | Professional & scientific | 2022 |
| Businessup Global Ltd | Information & communication | 2022 |
| Buttar Capital Ltd | Real estate | 2018 |
| Buyer Area Asset Management Ltd | Real estate | 2025 |
| Buzz Media UK Limited | Hospitality | 2009 |
| Buzzz Lightwear Clothing Limited | Wholesale & retail | 2025 |
| BW Konsult Limited | Professional & scientific | 2019 |
| Bxpn Safety Ltd | Professional & scientific | 2025 |
| Bygillian Ltd | Wholesale & retail | 2009 |
| Byland Ltd | Professional & scientific | 2025 |
| Byron Trading Limited | Wholesale & retail | 2021 |
| Bytebinders Limited | Wholesale & retail | 2025 |
| Bytemind IO Ltd | Information & communication | 2025 |
| C IS for Champagne Ltd | Wholesale & retail | 2018 |
| C Martin Consulting Limited | Professional & scientific | 2018 |
| C.A. Partnership Limited | Administrative & support | 1998 |
| C.I.A Chauffeuring Limited | Transport & logistics | 2018 |
| C.M.F. Limited | Manufacturing | 1982 |
| C.P.Robinson and Company Limited | Construction | 1992 |
| C2BI Ltd | Information & communication | 2011 |
| C8 Realisations 2026 Limited | Professional & scientific | 2006 |
| CA Consult Limited | Construction | 2005 |
| CA Foscarina Ltd | Professional & scientific | 2026 |
| Cabin Climate Control Limited | Construction | 2019 |
| Cadden Consulting Limited | Professional & scientific | 2026 |
| Caddy CUB Ltd | Wholesale & retail | 2024 |
| Caesars Building and Brickwork Ltd | Construction | 2022 |
| Cafe Chaiwala Slough Ltd | Hospitality | 2024 |
| Cafe Consultant Limited | Hospitality | 2025 |
| Cafe Coobinos Limited | Hospitality | 2019 |
| Cafe Roberto Limited | Hospitality | 2019 |
| Caffeine Tree Ltd | Hospitality | 2022 |
| Cake & Bake Club Limited | Manufacturing | 2024 |
| Cake Dolce Ltd | Wholesale & retail | 2025 |
| Calcworth Limited | Financial services | 2017 |
| Calder Court (Freehold) Limited | Households | 2000 |
| Calderbraes and Morningside Ltd | Professional & scientific | 2018 |
| Caledonian Advanced Pilot Training Limited | Education | 2008 |
| Calleva Consulting Limited | Professional & scientific | 2003 |
| Calm Little Minds Ltd | Education | 2023 |
| Calmed Developments Limited | Construction | 2003 |
| Calpin Marketing Ltd | Professional & scientific | 2020 |
| Calumite Limited | Manufacturing | 1969 |
| Cambridge Test Solutions Limited | Professional & scientific | 2010 |
| Camera Facilities Limited | Information & communication | 2010 |
| Cameron Builders Limited | Construction | 2025 |
| Camilleri Estates Ltd | Real estate | 2020 |
| Camley Park Residents Association (Pinkneys Green)Limited | Households | 1966 |
| Camosleeve Ltd | Wholesale & retail | 2023 |
| Campanita Marketing Ltd | Information & communication | 2024 |
| Camso Consulting Limited | Professional & scientific | 2011 |
| Camvertech Limited | Information & communication | 2009 |
| Canape Box Limited | Manufacturing | 2012 |