| Bright Stars Service Ltd | Education | 2016 |
| Bright Weld Engineering Ltd | Professional & scientific | 2026 |
| Brightaspect Limited | Professional & scientific | 1998 |
| Brightmore & Co Property Group Ltd | Real estate | 2025 |
| Brightmore Properties Ltd | Real estate | 2016 |
| Brina Trading Company Limited | Health & social care | 2024 |
| British Astronomical Association(The) | Education | 1911 |
| British Frozen Food Federation | Other services | 2011 |
| British Horological Institute Limited(The) | Other services | 1913 |
| British Sign and Graphics Association Ltd | Other services | 1988 |
| Britnell Tree Services Ltd | Agriculture & fishing | 2015 |
| Brits Money Ltd | Extraterritorial | 2016 |
| Britstone Ltd | Extraterritorial | 2022 |
| Broad Gate Services Ltd | Construction | 2023 |
| Broadwater Property Development Limited | Real estate | 2021 |
| Broadwaters Property Investments Limited | Real estate | 2018 |
| Brogolf Ltd | Arts & recreation | 2015 |
| Broodbakker Acoustic Consultants Limited | Professional & scientific | 2021 |
| Brook House Brewery Limited | Manufacturing | 2013 |
| Brooks & SON Plastering Ltd | Construction | 2026 |
| Brotech Systems Ltd | Manufacturing | 2013 |
| Brownhills Motorhomes EOT Limited | Administrative & support | 2022 |
| Brownhills Motorhomes Limited | Wholesale & retail | 1994 |
| Brunning Innovations Limited | Professional & scientific | 2021 |
| Brytespark Limited | Health & social care | 2009 |
| BS Portal Limited | Information & communication | 2020 |
| BT UK Digital Limited | Information & communication | 2025 |
| Buck Wealth Management Limited | Financial services | 2017 |
| Buckley Landscape Supplies Ltd | Other services | 2021 |
| Buckley Technical Services Limited | Professional & scientific | 2016 |
| Buildable Ltd | Construction | 2021 |
| Built Different Day Care Ltd | Health & social care | 2024 |
| Builtvision Films Limited | Professional & scientific | 2012 |
| Builtvision Limited | Professional & scientific | 2012 |
| Burchell Edmonds Ltd | Real estate | 2019 |
| Burden Court Limited | Real estate | 2020 |
| Burghley Bespoke Interiors Ltd | Manufacturing | 2023 |
| Burleigh Property Management Limited | Real estate | 2013 |
| Burnett Farming Holding Limited | Professional & scientific | 2018 |
| Burrowed Bunkers Ltd | Construction | 2026 |
| Burrowed Ltd | Construction | 2024 |
| Burton Logistics (Newark) Limited | Transport & logistics | 2008 |
| Burtons Beauty Ltd | Other services | 2024 |
| Business Athlete Services (UK) Ltd | Professional & scientific | 2013 |
| Buster Marquees Limited | Administrative & support | 2007 |
| Buttercross Estates Limited | Real estate | 2013 |
| Butterfly Poultry Limited | Hospitality | 1990 |
| Butters Electrical Services Limited | Construction | 2000 |
| BW Coaching Ltd | Education | 2025 |
| BW Contract Solutions Ltd | Administrative & support | 2025 |
| BY Juna Ltd | Information & communication | 2025 |
| C & G Hydraulic Services Limited | Manufacturing | 2014 |
| C and P Lakeside Holdings Limited | Financial services | 2022 |
| C J Hughes Properties Ltd | Real estate | 2026 |
| C R a T E Media Group Limited | Professional & scientific | 2019 |
| C S F Leisure Ltd | Other services | 2021 |
| C&D Quantity Surveying Limited | Professional & scientific | 2022 |
| C. G. Rhodes & Sons Limited | Construction | 1989 |
| C. T. Sheldon Limited | Agriculture & fishing | 1975 |
| C.A. Strawson & SON Limited | Agriculture & fishing | 2001 |
| C.A. Strawson Energy Limited | Energy | 1976 |
| C.A. Strawson Farming Limited | Agriculture & fishing | 2020 |
| C.A. Strawson Holdings Limited | Financial services | 2020 |
| C.A. Strawson Maplebeck Limited | Agriculture & fishing | 2020 |
| C.A.S.Y. | Health & social care | 2001 |
| C.E.Ceramics Ltd | Construction | 2020 |
| C.G.Burton & SON Limited | Agriculture & fishing | 1965 |
| C.J. Hempsall & Sons Limited | Agriculture & fishing | 1940 |
| C.M.I. Limited | Manufacturing | 1980 |
| C.P.S. (Aggregates) Limited | Construction | 1988 |
| C.T. Development (Nottingham) Ltd | Real estate | 2024 |
| C.W.Ellison Limited | Transport & logistics | 1954 |
| C2 Technology Group Ltd | Financial services | 2025 |
| Cabot Roofing Ltd | Construction | 2024 |
| Cadger Productions (UK) Ltd | Information & communication | 2018 |
| Cadman Consultants Limited | Information & communication | 1993 |
| Caesar Construction Ltd | Real estate | 2024 |
| Cafe Daisy Ltd | Hospitality | 2024 |
| Caffra Trading Limited | Public administration | 2014 |
| Caffrello Ltd | Hospitality | 2019 |
| Calculus Accounting Limited | Professional & scientific | 2009 |
| Calladine Group Ltd | Construction | 2017 |
| Calladines Surfacing Limited | Construction | 2013 |
| Callidusos Limited | Information & communication | 2025 |
| Callsageai Ltd | Administrative & support | 2025 |
| Calque Consulting Ltd | Information & communication | 2022 |
| Cambridge Court Management Company (WB) Limited | Households | 2002 |
| Cameron Watt Plumbing & Heating Limited | Construction | 2020 |
| Camino HR Limited | Professional & scientific | 2008 |
| Campion Pharma Solutions Limited | Administrative & support | 2025 |
| Camrax Ltd | Professional & scientific | 2016 |
| Canford Investments Limited | Real estate | 2025 |
| Cannon Piling Limited | Extraterritorial | 2002 |
| Cantel Computer Services Limited | Information & communication | 1985 |
| Cantrell Arenas Limited | Construction | 2008 |
| Canwood Limited | Professional & scientific | 2011 |
| Cape Building Services Limited | Construction | 2020 |
| Capla Developments Ltd. | Construction | 2007 |
| Capla Group Holdings Ltd. | Professional & scientific | 2008 |
| Capla Homes Ltd | Real estate | 2008 |