| Barbers Prestige Services Ltd | Other services | 2016 |
| Barnes & Sherwood Limited | Financial services | 1996 |
| Barre SET Ltd | Arts & recreation | 2022 |
| Barrington Hamilton Personal Asset Management Ltd. | Financial services | 2007 |
| Barry Attree E.A. Ltd | Real estate | 2026 |
| Barry Flodman Limited | Professional & scientific | 2003 |
| Bartlodge Limited | Real estate | 1998 |
| Bartlog Translations Ltd | Professional & scientific | 2025 |
| Base Management Ltd | Transport & logistics | 2022 |
| Basepoint Data Limited | Professional & scientific | 2010 |
| Bass Entertainment Ltd | Information & communication | 2021 |
| Baya Partners Ltd | Professional & scientific | 2025 |
| BB Dog Boutique Ltd | Wholesale & retail | 2022 |
| BC Accommodation Limited | Hospitality | 2016 |
| BC Global (Training) Ltd | Administrative & support | 2016 |
| BCT Properties Ltd | Construction | 2022 |
| BDR Heating and Plumbing Ltd | Construction | 2023 |
| BDS Gardening Limited | Administrative & support | 2023 |
| BDV Technology Limited | Professional & scientific | 2010 |
| BDW Accounting Services Ltd | Professional & scientific | 2021 |
| BE Light Limited | Construction | 2018 |
| Beamm Consulting Ltd | Professional & scientific | 2022 |
| Beancleaned Ltd | Administrative & support | 2025 |
| Beans BRU Ltd | Manufacturing | 2024 |
| Beaufort Equity Partners LLP | | 2011 |
| Beaufort Financial Planning Limited | Financial services | 2011 |
| Beauty Chic Rose Limited | Other services | 2011 |
| Beauty KLC Limited | Wholesale & retail | 2022 |
| Beauty Senses Limited | Wholesale & retail | 2008 |
| Bedfield Renovations Ltd | Construction | 2014 |
| Beenet Labs Ltd | Information & communication | 2021 |
| Beesparkly Events Ltd | Hospitality | 2025 |
| Belles Birdies Ltd | Arts & recreation | 2024 |
| Benbojet Limited | Manufacturing | 2026 |
| Benedetta Ferraro Limited | Professional & scientific | 2013 |
| Beneficial Fundraising Limited | Other services | 2016 |
| Benjamin Nyarko Anoff Limited | Health & social care | 2021 |
| Berkeley Quandt Consulting Ltd | Information & communication | 2012 |
| Berkshire Career Management Limited | Administrative & support | 1997 |
| Bermanfalk Hospitality Group UK Limited | Manufacturing | 2025 |
| Bernard Stone Associates Limited | Real estate | 2011 |
| Berney Communications Ltd | Professional & scientific | 2005 |
| Bertle Fisher Limited | Professional & scientific | 2021 |
| Bertrand Limited | Real estate | 1998 |
| Bespoke Eco Build Limited | Construction | 2025 |
| Bespoke Property Services Limited | Real estate | 2018 |
| Beth Huett Styling Ltd | Wholesale & retail | 2011 |
| Bhanjh Consulting Limited | Professional & scientific | 2024 |
| Bibaah Events Limited | Other services | 2019 |
| BID Logic Solutions Limited | Professional & scientific | 2023 |
| Big Brain Group Ltd | Wholesale & retail | 2019 |
| Big in Ibiza Limited | Information & communication | 2008 |
| Bigu Gourmet Catering Service Limited | Hospitality | 2026 |
| Bikebox Works Limited | Manufacturing | 2019 |
| Billy Byrne Limited | Professional & scientific | 2010 |
| BIM4U Ltd. | Information & communication | 2021 |
| Biohazard Services @ D&E Ltd | Water & waste | 2025 |
| Bioniq LAB Limited | Health & social care | 2020 |
| Bird’S EYE View Consulting Limited | Professional & scientific | 2025 |
| Birmingham Time Recorder Services Limited | Administrative & support | 1977 |
| Bitspire Limited | Information & communication | 2025 |
| BIZ DEV Consulting Ltd | Information & communication | 2022 |
| BJP Flooring Ltd | Wholesale & retail | 2026 |
| BJR Solutions Limited | Professional & scientific | 2014 |
| Black and Rust Limited | Manufacturing | 2025 |
| Black Dog Consultants UK Limited | Administrative & support | 2015 |
| Black HEN Limited | Real estate | 2015 |
| Black Sheep Inn Ltd | Hospitality | 2024 |
| Blackstone Marketing Solutions Limited | Professional & scientific | 2025 |
| Blade Contractors Ltd | Construction | 2019 |
| Blade K9 Security Ltd | Administrative & support | 2025 |
| Blend UP Interiors Ltd | Wholesale & retail | 2021 |
| Blended Industries Limited | Other services | 2006 |
| Blessings Healthcare Services Limited | Health & social care | 2010 |
| Blocc Investments Ltd | Real estate | 2018 |
| Block MB Ltd | Professional & scientific | 2023 |
| Blondy and Girls Ltd | Wholesale & retail | 2024 |
| Bloom & Boom Co Creative Ltd | Administrative & support | 2025 |
| Blooming Tech Limited | Information & communication | 2022 |
| Blue Box One Limited | Manufacturing | 2004 |
| Blue Bridge Property Ltd | Real estate | 2017 |
| Blue Finial Ltd. | Construction | 2005 |
| Blue Room IT Ltd | Information & communication | 2012 |
| Blue Sky CAD Limited | Professional & scientific | 2012 |
| Blue Sky Environmental (London) Ltd | Water & waste | 2013 |
| Blue Square Environmental Services Ltd | Construction | 2013 |
| Bluecapservices Limited | Administrative & support | 2012 |
| Bluefort Security Holdings Limited | Information & communication | 2019 |
| Bluefort Security Limited | Information & communication | 2007 |
| Bluelemon Safety and Training Ltd | Professional & scientific | 2018 |
| Blueridge Power Solutions Limited | Professional & scientific | 2024 |
| Bluewire Network Ltd | Extraterritorial | 2005 |
| Blum Haulage Ltd | Transport & logistics | 2016 |
| BMM JV Limited | Construction | 2013 |
| BMW (GB) Limited | Professional & scientific | 1994 |
| BMW (UK) Holdings Limited | Professional & scientific | 1975 |
| BMW (UK) Limited | Wholesale & retail | 1978 |
| BMW (UK) Manufacturing Limited | Manufacturing | 2000 |
| BMW (UK) Pensions Services Limited | Financial services | 1982 |
| BMW (UK) Trustees Limited | Professional & scientific | 1991 |