| Bring Italy Home Ltd | Wholesale & retail | 2020 |
| Brinklow Marina Ltd | Real estate | 2003 |
| Brio (Colton) Limited | Hospitality | 2011 |
| Brioche Burgers Ltd | Hospitality | 2026 |
| Briolf UK Limited | Wholesale & retail | 1999 |
| Bristan Group Limited | Wholesale & retail | 1977 |
| Bristol LEP Limited | Administrative & support | 2006 |
| Bristol LR (Hersey Gardens) Limited | Energy | 2025 |
| Bristol LR (Severn Road) Limited | Energy | 2025 |
| Bristol LR (Smoke Lane) Limited | Energy | 2025 |
| Bristol PFI (Holdings) Limited | Administrative & support | 2006 |
| Bristol PFI Debt Co 1 Limited | Administrative & support | 2006 |
| Bristol PFI Development Limited | Administrative & support | 2006 |
| Bristol PFI Limited | Administrative & support | 2006 |
| Brit Guarding Services Ltd | Administrative & support | 2022 |
| Brit Restaurants Ltd | Hospitality | 2015 |
| Britan Marketing Limited | Professional & scientific | 2025 |
| Britannia Bespoke Ltd | Construction | 2010 |
| Britannia Building & Roofing Ltd | Construction | 2023 |
| Britannia Construction Limited | Construction | 1974 |
| Britannia Cooling Limited | Manufacturing | 1988 |
| Britannia Food & Beverage Limited | Wholesale & retail | 2013 |
| Britannia FSG Ltd | Construction | 2025 |
| Britannia Group Limited | Construction | 1982 |
| Britannia Home Improvements (EY) Ltd | Construction | 2018 |
| Britannia House Management Company Limited | Households | 2000 |
| Britannia Stores Limited | Transport & logistics | 1982 |
| Britannia Systems Limited | Information & communication | 2025 |
| Britannia Textile Co. Limited | Manufacturing | 1984 |
| Britefuturemk Ltd | Wholesale & retail | 2025 |
| Britehub Technologies Limited | Information & communication | 2025 |
| Britgreen Energy Ltd | Professional & scientific | 2023 |
| British Aikido Association | Education | 2012 |
| British Composite Tiles Limited | Real estate | 1943 |
| British Epilepsy Association | Health & social care | 1964 |
| British Jeffrey Diamond 100 Limited | Manufacturing | 1996 |
| British Journal of Anaesthesia | Education | 2007 |
| British Power International Limited | Extraterritorial | 1995 |
| British Smaller Companies VCT PLC | Financial services | 1995 |
| British Smaller Companies VCT2 PLC | Financial services | 2000 |
| British Youth Music Theatre | Arts & recreation | 2003 |
| Britmag Limited | Manufacturing | 1997 |
| Britopia Holdings Limited | Administrative & support | 2025 |
| Brits Build Ltd | Construction | 2025 |
| Brits Grocery Company Limited | Wholesale & retail | 2023 |
| Brix and Co Leeds Ltd | Real estate | 2021 |
| Brixton and Mortar Limited | Real estate | 2016 |
| Brjr Investments Ltd | Real estate | 2021 |
| BRM Dentistry Ltd | Health & social care | 2026 |
| BRO Electrical Leeds Ltd | Construction | 2026 |
| Broad Manor Inns Limited | Hospitality | 2018 |
| Broad Peak Cyber Limited | Information & communication | 2024 |
| Broadbent Property Management Ltd | Real estate | 2021 |
| Broader Streets Consultancy Ltd | Professional & scientific | 2020 |
| Broadgate Court Limited | Households | 1973 |
| Broadgate Joinery Ltd | Manufacturing | 2025 |
| Broadhead Peel Rhodes Limited | Professional & scientific | 2009 |
| Broadhead Solutions Limited | Administrative & support | 2025 |
| Broadhold Limited | Professional & scientific | 2013 |
| Broadlea Mini Market Ltd | Wholesale & retail | 2021 |
| Broadley (Group) Limited | Construction | 2001 |
| Broadway Capital Group Ltd | Financial services | 2018 |
| Broadwise Solutions Ltd | Professional & scientific | 2024 |
| Broak Business Consultancy Limited | Professional & scientific | 2013 |
| Broaster Club Limited | Hospitality | 2025 |
| Brobin Limited | Wholesale & retail | 2017 |
| Brockley Electrical Services Ltd | Construction | 2025 |
| Brocks-Racing Ltd | Wholesale & retail | 2024 |
| Broco Halifax Limited | Real estate | 2020 |
| Brod Sandwich Bar Limited | Hospitality | 2013 |
| Brodetsky Jewish Primary School Foundation Trust | Education | 2013 |
| Brodie Cashmere Ltd | Wholesale & retail | 2021 |
| Brodra Ltd | Professional & scientific | 2013 |
| Brodrick Court Management Company Limited | Households | 2000 |
| Brodrick Management Limited | Professional & scientific | 2023 |
| Broella Building Ltd | Construction | 2026 |
| Brogden Property Group Ltd | Real estate | 2025 |
| Broken Branch Limited | Hospitality | 2025 |
| Broken Twill Ltd. | Transport & logistics | 2014 |
| Brokerplan Network Services Limited | Other services | 2020 |
| Bromby & Partners Limited | Administrative & support | 2025 |
| Bromley Investments Group Limited | Financial services | 2026 |
| Bromley Property Estates Limited | Real estate | 2026 |
| Brompton Equities | Professional & scientific | 2023 |
| Brondog Media Ltd | Professional & scientific | 2023 |
| Bronte Bathrooms Limited | Construction | 2022 |
| Bronte Tweed Ltd | Extraterritorial | 2023 |
| Brontide Media Ltd | Information & communication | 2017 |
| Brook Burn Limited | Professional & scientific | 2006 |
| Brook Consulting Limited | Information & communication | 2022 |
| Brook Investigations Limited | Administrative & support | 2012 |
| Brook of Eshcol Care Services Limited | Health & social care | 2016 |
| Brook Securities Ltd | Financial services | 2025 |
| Brook-Dobson Brear Limited | Financial services | 2006 |
| Brooke Thornham (Holdings) Limited | Professional & scientific | 2014 |
| Brooke Thornham Limited | Administrative & support | 2016 |
| Brooke Wood Group Limited | Agriculture & fishing | 2025 |
| Brookeview Care Ltd | Administrative & support | 2023 |
| Brookfield Court Management Company Limited | Other services | 1988 |
| Brookfield Parks Limited | Real estate | 1994 |