| Bohos Hairdressers Limited | Other services | 2013 |
| Boiler Team (Midlands) Limited | Other services | 2015 |
| Bolt Healthcare Providers Limited | Health & social care | 2025 |
| Bolton Grange Management Limited | Real estate | 1986 |
| Bolton Recruitment Ltd | Administrative & support | 2019 |
| Bonanza Letting Company Ltd | Real estate | 2011 |
| Bondi Solutions Ltd | Manufacturing | 2025 |
| Bone DOC Limited | Professional & scientific | 2014 |
| Bonefish Limited | Extraterritorial | 2012 |
| Bongalon Limited | Health & social care | 2021 |
| Bonsai Organisation Ltd | Administrative & support | 2019 |
| Bonymaen Inn Ltd | Hospitality | 2018 |
| Bonymaen RFC Limited | Arts & recreation | 2014 |
| BOO Town Limited | Real estate | 2022 |
| Boo's Business Limited | Hospitality | 2017 |
| Boobo Ltd | Hospitality | 2014 |
| Bookable Cloud Limited | Administrative & support | 2019 |
| Boomerang Care Ltd | Financial services | 2025 |
| Boomerang HR Ltd | Administrative & support | 2025 |
| Boosche Supplements Ltd | Other services | 2024 |
| Boosh Hairdressers Limited | Other services | 2015 |
| Booth’S Bakery Ltd | Manufacturing | 2019 |
| Boozehoundbar Ltd | Hospitality | 2025 |
| Bore Construction Limited | Construction | 2019 |
| Boriska Pharma Ltd | Agriculture & fishing | 2026 |
| Boro Inns Limited | Hospitality | 2017 |
| BOS Resources Limited | Water & waste | 2010 |
| Bospeed Transport Ltd | Transport & logistics | 2021 |
| Boss Skin & Wellness Ltd | Other services | 2026 |
| Bossman Retail Group Ltd | Wholesale & retail | 2024 |
| Boston Securities Limited | Real estate | 1994 |
| BOT8 Ltd | Information & communication | 2023 |
| Botizan Logistics Ltd | Transport & logistics | 2016 |
| Boughan Professional Cleaning Ltd | Administrative & support | 2025 |
| Boughan Properties Ltd | Real estate | 2026 |
| Boughton PUB Ltd | Hospitality | 2018 |
| Boujee Bagels Ltd | Hospitality | 2026 |
| Boulders Site 3 Ltd | Arts & recreation | 2022 |
| Boundri Ltd. | Information & communication | 2022 |
| Bountiful Catering Ltd | Hospitality | 2025 |
| Boutique Entertainment Ltd | Arts & recreation | 2026 |
| Bowbird Consultancy Limited | Education | 2022 |
| Bowen Arms Limited | Hospitality | 2019 |
| Bowen Hopkins Limited | Construction | 1980 |
| Bowl & Beyond Ltd | Transport & logistics | 2026 |
| Bowl Protect Ltd | Wholesale & retail | 2025 |
| Bowyer Group Limited | Real estate | 2023 |
| Box Steam Brewery Limited | Manufacturing | 2011 |
| BOX39 Ltd | Real estate | 2022 |
| Boxednights Ltd | Wholesale & retail | 2019 |
| Boyd Healthcare Ltd | Wholesale & retail | 2017 |
| Boyd London Limited | Information & communication | 2012 |
| Boys Ballet Ltd | Administrative & support | 2014 |
| BP Online Ltd | Extraterritorial | 2024 |
| BPD Media Limited | Information & communication | 2023 |
| BPO Insolvency Limited | Financial services | 2015 |
| BR Forklift Training Services Limited | Transport & logistics | 2017 |
| BR Joinery Limited | Construction | 2022 |
| BR Property Holdings Ltd | Households | 2024 |
| Brace & Presswell Holdings Limited | Professional & scientific | 1992 |
| Bradbar Construction Limited | Construction | 2021 |
| Bradbar Homes Limited | Construction | 2020 |
| Bradbar Limited | Construction | 2016 |
| Bradsan Limited | | 1971 |
| Braidlink Ltd | Information & communication | 2026 |
| Bramble & Birch Ltd | Hospitality | 2022 |
| Bramble and Nettle CIC | Agriculture & fishing | 2022 |
| Bramley Hill Management Limited | Real estate | 1996 |
| Branching OUT Tree Consultancy Limited | Other services | 2015 |
| Brandspace Ltd | Information & communication | 2022 |
| Brave Arts Theatre Company Ltd | Arts & recreation | 2022 |
| Brave Guarding Ltd | Other services | 2023 |
| Bravo Mart Limited | Wholesale & retail | 2021 |
| Bread and Butter Collection Limited | Wholesale & retail | 2021 |
| Breathe Talent & Learning Ltd | Administrative & support | 2014 |
| Breathwork for Children CIC | Education | 2025 |
| Brecon Beacons Candle Company Ltd | Manufacturing | 2025 |
| Brecon Events | Information & communication | 2019 |
| Brecon Ridge Consulting Ltd | Hospitality | 2008 |
| Breeze Bay Drinks Ltd | Wholesale & retail | 2024 |
| Breeze's Gym Ltd | Arts & recreation | 2012 |
| Brentacre Insurance Services Limited | Financial services | 1986 |
| Brentacre Racing Limited | Arts & recreation | 2022 |
| Breops Ltd | Hospitality | 2026 |
| Bretlands Limited | Real estate | 2019 |
| Brew Enterprises Ltd | Professional & scientific | 2022 |
| Brewcap Limited | Wholesale & retail | 2026 |
| Brewgas Suppliers Ltd | Energy | 2025 |
| Brewstone OPS Ltd | Hospitality | 2015 |
| Brewtech Ltd | Hospitality | 2016 |
| Briallen Toys Limited | Wholesale & retail | 2021 |
| Bridal Bouquet Charms Ltd | Manufacturing | 2017 |
| Bridal Collective UK Ltd | Wholesale & retail | 2011 |
| Bridgend Inn (Birchgrove) Limited | Hospitality | 2024 |
| Bridgend Self Storage Ltd | Transport & logistics | 2000 |
| Bridger Brothers Limited | Hospitality | 2024 |
| Brienda Vintage Limited | Wholesale & retail | 2021 |
| Brigdale Property Ltd | Real estate | 2020 |
| Briggs Coaches Limited | Transport & logistics | 2004 |
| Bright Gems Learning Hub Ltd | Education | 2025 |