| Bubnov Ltd | Transport & logistics | 2018 |
| Bucci Botanicals Limited | Manufacturing | 2024 |
| Bucci Property Company Ltd | Real estate | 2026 |
| Bucharest Express Ltd | Wholesale & retail | 2022 |
| Budgen Holdings Limited | Wholesale & retail | 1919 |
| Budgens Pension Trustees NO.2 Limited | Administrative & support | 2015 |
| Budgens Property Investments Limited | Extraterritorial | 2000 |
| Budgens Stores Limited | Wholesale & retail | 1962 |
| Build Greener Ltd | Wholesale & retail | 2021 |
| Buildplumb Limited | Construction | 2025 |
| Buildwise Realty Ltd | Construction | 2020 |
| Built by ME Group Ltd | Administrative & support | 2026 |
| Buku Trans Ltd | Transport & logistics | 2014 |
| Bulut Limited | Manufacturing | 2015 |
| Bumpstop Limited | Professional & scientific | 2010 |
| Burger Boulevard Ltd | Hospitality | 2025 |
| Burnolk Property Limited | Real estate | 2021 |
| Burrows & Sons Construction Limited | Construction | 2014 |
| Business Gears Limited | Professional & scientific | 2013 |
| Business Growth Northants Limited | Administrative & support | 2026 |
| Bust a Brunch Ltd | Hospitality | 2025 |
| BWA RSS Ltd | Wholesale & retail | 2020 |
| Bwaraat Group Ltd | Extraterritorial | 2021 |
| BWM Business Solutions Limited | Extraterritorial | 2019 |
| BWT Capital Group Ltd | Financial services | 2018 |
| BY AMY Aesthetics Limited | Other services | 2023 |
| Byrnes MOT and Repair Centre Ltd | Wholesale & retail | 2020 |
| Byrnie Ltd | Wholesale & retail | 2020 |
| Byron PUB Group Ltd | Hospitality | 2016 |
| Bywater Herring Limited | Real estate | 2018 |
| Byways Developments Limited | Construction | 2013 |
| C & H Group Ltd | Construction | 2025 |
| C & H Utilities Limited | Construction | 2021 |
| C & R Consultancy Ltd | Administrative & support | 2025 |
| C and Co Hair Salon Ltd | Administrative & support | 2017 |
| C C & D Chaplin Plumbing & Drainage Limited | Construction | 2009 |
| C D Tazob Plumbing and Heating Limited | Construction | 2017 |
| C Denney Contractors Limited | Construction | 2016 |
| C Halsall Limited | Wholesale & retail | 2022 |
| C J Civil Engineering Limited | Construction | 2024 |
| C KEW Facade Solutions Limited | Construction | 2000 |
| C KEW Installations Limited | Construction | 1999 |
| C L Waite Ltd | Construction | 2014 |
| C S Goodwin Plumbing & Heating Limited | Construction | 2017 |
| C&D Taylor Properties Ltd | Real estate | 2020 |
| C&J Coaching and Consulting Ltd | Professional & scientific | 2024 |
| C&S Borta Construction Ltd | Construction | 2025 |
| C-Lec Electrical Ltd | Construction | 2018 |
| C. Goddard Group Ltd | Real estate | 2021 |
| C. Goddard Holdings Limited | Professional & scientific | 1975 |
| C. Goddard Properties Ltd | Real estate | 2021 |
| C.B.A.C. Ltd | Professional & scientific | 1997 |
| C.D.R. Pumps UK Limited | Wholesale & retail | 1998 |
| C.P.Mechanical Maintenance Ltd | Professional & scientific | 2022 |
| C.R. Getaways Ltd | Hospitality | 2022 |
| Cab-X Software Ltd | Information & communication | 2026 |
| Cable-Wright Solutions Limited | Professional & scientific | 2016 |
| CAD Haulage Ltd | Other services | 2021 |
| Cadge & Colman Limited | Professional & scientific | 1897 |
| Cads Property Ltd | Real estate | 2024 |
| Cafria Limited | Health & social care | 2013 |
| Cagtrans Ltd | Transport & logistics | 2021 |
| CAH Holdings Ltd | Professional & scientific | 2016 |
| Cakesbylulu Ltd | Manufacturing | 2020 |
| Calcutta Rose Limited | Real estate | 2024 |
| Calderstone Design & Print Limited | Manufacturing | 1990 |
| Callesports Ltd | Wholesale & retail | 2023 |
| Calm Circle Ltd | Wholesale & retail | 2025 |
| Calorie Restaurant Ltd | Hospitality | 2018 |
| CAM Supported Living CIC | Health & social care | 2019 |
| Cambio Investments Limited | Real estate | 2026 |
| Camel Power Limited | Financial services | 2014 |
| Cameron Wollaston Services Ltd | Information & communication | 2019 |
| CAN Scot Limited | Health & social care | 2004 |
| Canary Coaching Limited | Professional & scientific | 2024 |
| Candidbond Limited | Households | 1988 |
| Candle Boutique Ltd | Households | 2012 |
| Canham R Limited | Wholesale & retail | 2023 |
| Cantech Deploy Limited | Information & communication | 2022 |
| Cantello Consultancy Limited | Professional & scientific | 2004 |
| Canton Feast Limited | Hospitality | 2021 |
| Capehouse Limited | Hospitality | 2022 |
| Capital Property London Limited | Real estate | 2016 |
| Capite Linden (Regent Park 2) Limited | Real estate | 2019 |
| Capite Linden (Regent Park) Limited | Real estate | 2002 |
| Capple Limited | Professional & scientific | 2014 |
| Car Technology Limited | Wholesale & retail | 2014 |
| Car Wash Yard Ltd | Administrative & support | 2023 |
| Carbonautoclean Ltd | Wholesale & retail | 2020 |
| Carcris Ltd | Construction | 2020 |
| Cardbargainsuk Limited | Wholesale & retail | 2020 |
| Cardioxplore Ltd | Health & social care | 2022 |
| Care 4 U Services (Lincs) Ltd | Health & social care | 2008 |
| Carepacity Ltd | Health & social care | 2021 |
| Caretaker & Sons Ltd | Construction | 2024 |
| Careupp Limited | Public administration | 2024 |
| Careupp Property Group Limited | Real estate | 2024 |
| Cargo Correct Ltd | Transport & logistics | 2019 |
| Caribbean Flava Ltd | Hospitality | 2017 |
| Caribbean Flavas Catering Ltd | Hospitality | 2024 |