| Bocking Builds Limited | Construction | 2021 |
| Bocking Homes Limited | Real estate | 2017 |
| Bocking Moon Limited | Real estate | 2020 |
| Bocking Thorpe High ST SPV Limited | Real estate | 2023 |
| BOD Brands Limited | Professional & scientific | 2024 |
| BOD Global Ltd | Wholesale & retail | 2025 |
| Body and Mind Limited | Health & social care | 1999 |
| Bold Mediation Ltd | Other services | 2025 |
| Boley Nutraceuticals Ltd. | Manufacturing | 2016 |
| Bolt Media Limited | Professional & scientific | 2025 |
| Bond Surveying Ltd | Professional & scientific | 2024 |
| Bonum Care Ltd | Health & social care | 2023 |
| Book Investments Limited | Real estate | 2024 |
| Books of Asia Ltd | Wholesale & retail | 2022 |
| Bordelaise Ewell Limited | Hospitality | 2025 |
| Border Telecom Maintenance Limited | Information & communication | 1996 |
| Borough High Street Management Company Limited | Real estate | 1999 |
| Borussia London FC Ltd | Arts & recreation | 2023 |
| Bosanquet Ives Ltd | Manufacturing | 2013 |
| Bosdet Media Limited | Information & communication | 2016 |
| Boston Court (Selhurst Road) Management Limited | Real estate | 1970 |
| Botrodger Consulting Ltd | Professional & scientific | 2013 |
| Bourne Beauty Rooms Ltd | Other services | 2023 |
| Bourne Contracts Ltd | Construction | 2025 |
| Bourne Court Management (Purley) Limited | Real estate | 1976 |
| Bourne Education Trust | Education | 2011 |
| Bourne Education Trust Enterprises Limited | Education | 2014 |
| Bourne Hill Holdings Limited | Wholesale & retail | 2018 |
| Bourne Hill Stables Limited | Agriculture & fishing | 2012 |
| Boutiqolux Ltd | Wholesale & retail | 2019 |
| Bowshot Consulting Limited | Administrative & support | 2013 |
| Box Lees Limited | Households | 1988 |
| Box Tree Pubs & Bars Limited | Hospitality | 2016 |
| Boyd House Management Limited | Households | 1981 |
| BPP Construction Consultants LLP | | 2005 |
| BPW Holdings Limited | Financial services | 2016 |
| BR44A Ltd | Construction | 2025 |
| Bracondale Freehold Ltd | Real estate | 2024 |
| Bradbury Animal Care Limited | Professional & scientific | 2024 |
| Bradley & Arthur Ltd | Construction | 2018 |
| Braggie Ltd | Professional & scientific | 2025 |
| Bramshott House Properties Limited | Health & social care | 2026 |
| Bramshott Pharma Limited | Manufacturing | 2020 |
| Brand Directors London Ltd | Information & communication | 2019 |
| Brandinn Business Trading & Solutions Ltd | Wholesale & retail | 2011 |
| Brandmine Properties Limited | Real estate | 2009 |
| Bratos Ltd | Wholesale & retail | 2025 |
| Brava Construction Ltd | Construction | 2016 |
| Brava Developments Ltd | Construction | 2011 |
| Brave Dolls Ltd | Wholesale & retail | 2020 |
| Bravemouth Consulting Limited | Information & communication | 2012 |
| Breakaway Coaching and Analytics (BCA) Limited | Other services | 2020 |
| Brentdean Limited | Administrative & support | 1986 |
| Brett Systems Ltd | Information & communication | 2026 |
| Brett's Gardens Ltd | Administrative & support | 2017 |
| Brew & Bhel UK Limited | Hospitality | 2025 |
| BRI Chinese Healthcare Centre Limited | Health & social care | 2019 |
| Briarglen (Management) Limited | Households | 1977 |
| Briavels Management (Epsom) Limited | Households | 1966 |
| Brick Restore Ltd Ltd | Construction | 2013 |
| Brickline Properties Limited | Real estate | 2008 |
| Bricko Limited | Construction | 2019 |
| Bridge Advisory London Ltd | Professional & scientific | 2024 |
| Bridge Apps Ltd. | Information & communication | 2014 |
| Bridge Consulting London Ltd | Professional & scientific | 2018 |
| Bridged Technologies Limited | Information & communication | 2024 |
| BRIDGEF61 Limited | Information & communication | 2025 |
| Bridger Bell Commercial LLP | | 2013 |
| Bridgeroad Technology Ltd | Information & communication | 2025 |
| Bridges Studios Ltd | Other services | 2025 |
| Bright and White Care Limited | Health & social care | 2022 |
| Bright Bricks Ltd | Manufacturing | 2010 |
| Bright Green Garden Ltd | Other services | 2017 |
| Bright Homes Builders Limited | Construction | 2024 |
| Bright Sky HR Ltd | Professional & scientific | 2016 |
| Bright Sky Innovations Ltd | Construction | 2022 |
| Bright Spark Games Ltd | Manufacturing | 2026 |
| Brightbridge Group Limited | Real estate | 2025 |
| Brightroute Cars Ltd | Transport & logistics | 2026 |
| Brightwater Brewery Limited | Manufacturing | 2012 |
| Brilliance Limited | Health & social care | 2021 |
| Brilliant Commercial Cleaning Ltd | Administrative & support | 2023 |
| Brilliant Media Group Ltd | Information & communication | 2021 |
| Brimfield Investments | Financial services | 2026 |
| Brimley-Cato Limited | Health & social care | 2013 |
| Brisker Holdings Ltd | Real estate | 2023 |
| Brita Projects Ltd | Construction | 2024 |
| Britannia Garden Services Ltd | Administrative & support | 2013 |
| Britline Travels Ltd | Transport & logistics | 2024 |
| Britquest Limited | Administrative & support | 2003 |
| Brits Envirotech Limited | Manufacturing | 2025 |
| Briventa Ltd | Wholesale & retail | 2025 |
| Brixon Construction Ltd | Construction | 2025 |
| BRL LOG Ltd | Transport & logistics | 2025 |
| BRN Store Ltd | Wholesale & retail | 2023 |
| Broadcast (1996) Limited | Arts & recreation | 1996 |
| Broadfield Capital Partners LLP | | 2025 |
| Broadgate Trading Limited | Hospitality | 2015 |
| Broadlands Grange Management Company Limited | Households | 2007 |
| Broadwater Place Management Company Limited | Households | 1996 |