| Brickmafia Ltd | Wholesale & retail | 2025 |
| Brickmakers Ipswich Ltd | Hospitality | 2018 |
| Bricks and Patterns Limited | Real estate | 2023 |
| Bridge & Woods Limited | Hospitality | 2020 |
| Bridge and IVY Farms Limited | Agriculture & fishing | 1961 |
| Bridge Hotels Ipswich Limited | Hospitality | 2004 |
| Bridge MOT Ipswich Ltd | Wholesale & retail | 2024 |
| Bridge Realty & Design Limited | Real estate | 2024 |
| Bridge Shipping and Transport Co. Limited | Transport & logistics | 1987 |
| Bridge Sure Ltd | Wholesale & retail | 2025 |
| Bridgefellows Academy International Limited | Education | 2017 |
| Bridgefellows Consultancy Limited | Professional & scientific | 2018 |
| Bridgefellows International Limited | Professional & scientific | 2016 |
| Bridgewell Healthcare Ltd | Administrative & support | 2026 |
| Bridgewood Property Holdings Limited | Real estate | 2009 |
| Briefvanta Service Pages Ltd | Information & communication | 2026 |
| Bright Build Anglia Limited | Construction | 2006 |
| Bright Carbon Solutions Ltd | Professional & scientific | 2024 |
| Bright Infrastructure Ltd | Financial services | 2021 |
| Bright Sun West 12 MAY Ltd | Information & communication | 2026 |
| Bright Transitions Ltd | Health & social care | 2023 |
| Bright Ventures Limited | Hospitality | 2014 |
| Brighter Days Family Ltd | Information & communication | 2025 |
| Brighter Miles Limited | Professional & scientific | 2025 |
| Brighthead Technology Limited | Administrative & support | 2000 |
| Brighthold Care Solutions CIC | Health & social care | 2025 |
| Brightlingsea Motors Ltd | Transport & logistics | 2022 |
| Brightpath Global Limited | Professional & scientific | 2026 |
| Brightsky Fireworks Limited | Wholesale & retail | 2009 |
| Brightwave Media Ltd | Information & communication | 2024 |
| Brightwell Capital Limited | Financial services | 2022 |
| Brightwell Commercial Properties Ltd | Real estate | 2002 |
| Brightwell Computers Limited | Information & communication | 2006 |
| Brightwell Developments Ltd | Construction | 2017 |
| Brightwell Estates Limited | Construction | 2012 |
| Brightwell Property Limited | Financial services | 2023 |
| Brighty Consulting Limited | Professional & scientific | 2024 |
| Brimlin Media Limited | Professional & scientific | 2003 |
| Brimstone Psychology Limited | Education | 2022 |
| Brinor (Holdings) Limited | Professional & scientific | 1983 |
| Brinor International Shipping and Forwarding Limited | Transport & logistics | 1979 |
| Brisetechnical Limited | Administrative & support | 2016 |
| Brisko Scaffolding Limited | Construction | 1996 |
| Bristo's Limited | Wholesale & retail | 2003 |
| Bristow Holland Limited | Administrative & support | 2013 |
| Britannia Management (Ipswich) Limited | Real estate | 2015 |
| Britannialink Limited | Administrative & support | 2001 |
| Britanniamover Logistics Ltd | Extraterritorial | 2026 |
| Britcar Global Ltd | Wholesale & retail | 2022 |
| Britesy Healthcare Ltd | Health & social care | 2025 |
| Britflow Finance Ltd | Extraterritorial | 2026 |
| British Association for Immediate Care | Education | 1998 |
| British Chamber of Commerce for Italy(Incorporated)(The) | Other services | 1914 |
| British Elite Athletes Association Limited | Arts & recreation | 2004 |
| British Guild of Travel Writers Limited | Other services | 2015 |
| British Iranian Insurance Association Limited | Extraterritorial | 2017 |
| British Promotional Merchandise Association Limited | Other services | 2002 |
| Britlink Consulting Ltd | Professional & scientific | 2025 |
| Brits Market Limited | Wholesale & retail | 2025 |
| BRM Trans Ltd | Transport & logistics | 2018 |
| Broachlight Limited | Professional & scientific | 1982 |
| Broad Beam Property Limited | Real estate | 2021 |
| Broadstream Holdings Limited | Professional & scientific | 2007 |
| Broc Homes Ltd | Real estate | 2023 |
| Brochure Holders International Limited | Manufacturing | 2017 |
| Brockford Accident Repair Centre Limited | Transport & logistics | 1994 |
| Brodie Consulting Limited | Financial services | 2019 |
| Brodie Partners Ltd | Administrative & support | 2018 |
| Broke Hall Management Limited | Households | 2023 |
| Broke Hall Park Limited | Real estate | 2017 |
| Brokersure Group Ltd | Professional & scientific | 2011 |
| Brokersure Ltd | Financial services | 2009 |
| Bromeline Services Ltd | Real estate | 2025 |
| Bromley and Fitch Limited | Wholesale & retail | 2003 |
| Bromley BID Limited | Administrative & support | 2014 |
| Bromline Services Ltd | Professional & scientific | 2026 |
| Brook Electrical Services Ltd. | Construction | 2016 |
| Brook IT Consulting Ltd | Information & communication | 2023 |
| Brook Residential Limited | Real estate | 2021 |
| Brook Street Foodservice Limited | Wholesale & retail | 1990 |
| Brookfield Automotive Limited | Wholesale & retail | 2023 |
| Brookhouse Management Company Limited | Households | 1988 |
| Brookhouse Parts Ltd. | Wholesale & retail | 2009 |
| Brooki Limited | Extraterritorial | 1999 |
| Brooks & Wood (Building) Limited | Construction | 1984 |
| Brooks and Wood Group Limited | Financial services | 2015 |
| Brooks and Wood Limited | Construction | 1974 |
| Brooks Hall Rovers Football Club CIC | Arts & recreation | 2025 |
| Brooks RAC Limited | Construction | 2021 |
| Brooks Timber Supplies Ltd | Other services | 2021 |
| Brooks-Harper Recruitment Ltd | Administrative & support | 2019 |
| Brookwood Investments Limited | Administrative & support | 2006 |
| Brookwood MH | Financial services | 2023 |
| Brothers Colquhoun Ltd | Real estate | 2022 |
| Brothers Cuts Ltd | Other services | 2024 |
| Broughton (Thermal Insulation) Limited | Extraterritorial | 1983 |
| Brown & Brown Design Associates Limited | Professional & scientific | 2011 |
| Brown END White Limited | Manufacturing | 2025 |
| Brown Properties Ltd | Real estate | 2012 |
| Brown Roofing Ltd | Construction | 2025 |