| Brightonsmiles Limited | Health & social care | 2021 |
| Brightsea Consulting Ltd | Professional & scientific | 2024 |
| Brightvent Ltd. | Construction | 2017 |
| Brightwood Limited | Real estate | 2010 |
| Brijin Limited | Extraterritorial | 2006 |
| Brilliant Little Business Limited | Information & communication | 2019 |
| Bristol Consultancy LLP | | 2023 |
| Britannia House Developments Limited | Construction | 2015 |
| Britetone Limited | Professional & scientific | 2019 |
| British Culture Residential Education Centre Limited | Administrative & support | 2023 |
| Britton Price Hoists (NI) Limited | Manufacturing | 2015 |
| Britton Price Hoists Limited | Manufacturing | 2014 |
| Britton Price Holdings Limited | Manufacturing | 2015 |
| Britton Price Lifts (LG) Ltd | Manufacturing | 2019 |
| Britton Price Lifts Limited | Manufacturing | 2015 |
| Britton Price Limited | Manufacturing | 1996 |
| Britton Price Training Limited | Manufacturing | 2016 |
| BRL Consulting Limited | Administrative & support | 2025 |
| Brmh Ltd | Real estate | 2017 |
| Broad Street Properties (Seaford) Limited | Real estate | 2014 |
| Broadband for Rural Kent Ltd | Information & communication | 2020 |
| Broadhead Consulting Limited | Information & communication | 2018 |
| Broadoak Incorporated Ltd | Construction | 2022 |
| Broadplastering & Refurbishments Limited | Construction | 2026 |
| Broadreach Software Limited | Information & communication | 2008 |
| Broadwater Osteopathic Practice Limited | Health & social care | 2014 |
| Brodwolf Ltd | Manufacturing | 2020 |
| Bromhead Family Limited | Administrative & support | 2025 |
| Brook Property Limited | Real estate | 2018 |
| Brooklake BIO Ltd | Wholesale & retail | 2025 |
| Brookly Ltd. | Professional & scientific | 2019 |
| Brooks Haus Ltd | Real estate | 2025 |
| Brooks Rose Limited | Administrative & support | 2019 |
| Broom & Moon Ltd | Professional & scientific | 2023 |
| Bror Coffee Ltd | Manufacturing | 2023 |
| Brough Search Limited | Administrative & support | 2017 |
| Brownlow Stem Tutoring Ltd | Education | 2024 |
| BRS Network Ltd | Administrative & support | 2013 |
| Bruce White Music Ltd | Other services | 2013 |
| Brunswick 17 Limited | Construction | 2007 |
| Brunswick Chase SPV 1 Ltd | Real estate | 2018 |
| Brunswick Cosmetic Clinic Limited | Health & social care | 2015 |
| Brunswick Court Dental Practice Limited | Health & social care | 2007 |
| Brunswick Events Limited | Arts & recreation | 2025 |
| Brunswick House (Hove) RTM Company Limited | Extraterritorial | 2025 |
| Brunswick Studios Ltd | Real estate | 2021 |
| Brunswick Terrace Residents Association Limited | Households | 1998 |
| Brunswick Town Property Management Ltd. | Households | 1996 |
| Bryan Barker (Builders) Limited | Construction | 1996 |
| Brymon Airways Limited | Transport & logistics | 2017 |
| Brymore Family Holdings Ltd | Financial services | 2018 |
| Brymore Holdings Limited | Professional & scientific | 2009 |
| Brymore Organisation Ltd | Financial services | 2018 |
| Bryony Thomas Careers Consulting Limited | Education | 2021 |
| BS Fairclough Consulting Limited | Administrative & support | 2014 |
| BSA Brands (UK) Limited | Wholesale & retail | 2018 |
| BT Consulting Services Ltd | Professional & scientific | 2015 |
| BTN Glazing Ltd | Construction | 2021 |
| Btnproperties Ltd | Hospitality | 2026 |
| Buckingham Telecom Limited | Information & communication | 2018 |
| Buckinghamshire Psychology Limited | Health & social care | 2013 |
| Buckland Consultancy Ltd | Information & communication | 2025 |
| Bucklersbury Flat Management Limited | Extraterritorial | 1991 |
| Bucknall Property Group Ltd | Real estate | 2020 |
| Bucksham Avenue (Bognor) Limited | Households | 2016 |
| Buddha Hove Nail Ltd | Other services | 2026 |
| Buddha Nail Salon Limited | Other services | 2022 |
| Buddha on the Board Ltd | Professional & scientific | 2021 |
| Buenos Dias Ltd | Professional & scientific | 2007 |
| Buggy Estates Ltd | Real estate | 2023 |
| Build My Home Ltd | Construction | 2013 |
| Builderstorm Limited | Information & communication | 2014 |
| Building Future Investments Limited | Financial services | 2024 |
| Building Solutions Consultants Limited | Professional & scientific | 2006 |
| Buildsource Limited | Construction | 2011 |
| Built Brighton Ltd | Construction | 2023 |
| Bull Cartel Ltd | Wholesale & retail | 2024 |
| Bullyz & Beyond Ltd | Agriculture & fishing | 2022 |
| Bunce Properties Ltd | Real estate | 2019 |
| Bunker Recordings Ltd | Information & communication | 2023 |
| Buonalingua Ltd | Professional & scientific | 2024 |
| Burdekin Consulting Limited | Information & communication | 2014 |
| Burleigh Rock Limited | Real estate | 2019 |
| Burnham Wick Solar Limited | Energy | 2013 |
| Burning Sage Ltd | Health & social care | 2025 |
| Burntandmore Ltd | Wholesale & retail | 2025 |
| Burrwood LLP | | 2014 |
| Bury Green Farm Solar Limited | Energy | 2015 |
| Business Acceleration Ltd | Administrative & support | 2018 |
| Business English Consultancy Limited | Professional & scientific | 2012 |
| Business Expansion Solutions Ltd | Administrative & support | 2013 |
| Business for Good Ltd | Professional & scientific | 2020 |
| Business Management Consultation Ltd | Professional & scientific | 2016 |
| Business Psychology Ltd | Professional & scientific | 2024 |
| Business United CIC | Other services | 2024 |
| Buster Consulting Ltd | Administrative & support | 2016 |
| Buteco BH Limited | Hospitality | 2024 |
| Butterflies Forever | Education | 2017 |
| Buttermere Capital Limited | Financial services | 2018 |
| Button Nose Bakery Ltd | Manufacturing | 2025 |