| Best Buy Sales Ltd | Information & communication | 2023 |
| Best Heyday Ltd | Hospitality | 2025 |
| Best Maids Ltd | Administrative & support | 2025 |
| Best Time Cleaning Services Limited | Administrative & support | 2021 |
| Bestitrecruitments Limited | Information & communication | 2015 |
| Beta 94 Limited | Transport & logistics | 2018 |
| Betaturk Ltd | Real estate | 2020 |
| Betyar Ltd | Transport & logistics | 2014 |
| Beulah Soft Limited | Information & communication | 2013 |
| Bevenny Manufacturing Ltd. | Manufacturing | 2007 |
| Beyond Basic Bubbles Ltd | Manufacturing | 2021 |
| Beyond IT Ltd | Information & communication | 2021 |
| Beyond Procurement Ltd | Professional & scientific | 2007 |
| Beyond the Page Gallery Limited | Wholesale & retail | 2021 |
| Beypinar Ltd | Hospitality | 2018 |
| Bfdd Ltd | Information & communication | 2024 |
| Bfsi UK Ltd | Professional & scientific | 2022 |
| BGP Corporation Limited | Professional & scientific | 2021 |
| BGS Estates Ltd | Real estate | 2025 |
| Bhaga Properties Limited | Real estate | 2025 |
| Bhip Ltd | Hospitality | 2025 |
| Bi-Rent (Coventry) Limited | Construction | 1966 |
| BIB Performance Limited | Wholesale & retail | 2020 |
| Bichescu Ltd | Transport & logistics | 2024 |
| BID Support Ltd | Professional & scientific | 2015 |
| Bidean Assets Limited | Real estate | 2021 |
| Bielathor Ltd | Wholesale & retail | 2016 |
| Big Bear Events Limited | Arts & recreation | 2016 |
| Big Bright Futures Ltd | Real estate | 2021 |
| Big Brown Bear Ltd | Transport & logistics | 2019 |
| Big Green Property Ltd | Real estate | 2024 |
| Big People Music Community UK CIC | Information & communication | 2025 |
| Biggleswade Holdco Limited | Financial services | 2023 |
| Bilal Warriach Property Ltd | Real estate | 2025 |
| Bilko Aviation Limited | Other services | 2022 |
| Billy MC Transport Limited | Transport & logistics | 2017 |
| Bilton Architectural Services Limited | Professional & scientific | 2012 |
| Bilton Court (Rugby) Management Company Limited | Households | 2005 |
| Bilton Evangelical Church | Other services | 2010 |
| Bilton Fields Farm Homes Limited | Real estate | 2019 |
| Bilton Fields Limited | Households | 2019 |
| Bilton Grange Foundation Limited | Education | 2009 |
| Bilton Kitchen Co. Ltd | Wholesale & retail | 2010 |
| Bilton Mechanical Services Limited | Construction | 2005 |
| Bilton Sunbeams Pre-School Ltd | Education | 2011 |
| Bilton Tennis Club Limited | Arts & recreation | 1993 |
| Bimd Ltd | Professional & scientific | 2017 |
| Bimmer World Limited | Wholesale & retail | 2026 |
| Binary Consultants Ltd | Information & communication | 2025 |
| Binder Packs Ltd | Manufacturing | 2025 |
| Binek Trans Ltd | Transport & logistics | 2018 |
| Binestar Group Ltd | Construction | 2025 |
| Binswood Properties Ltd | Construction | 2020 |
| Birth Boutique Ltd | Health & social care | 2021 |
| Bisanli Design Ltd | Professional & scientific | 2026 |
| Bison Nutrition Ltd | Other services | 2023 |
| Bitok Ltd | Transport & logistics | 2025 |
| BJ Infotainments Ltd | Manufacturing | 2022 |
| BJC NIK Service Ltd | Wholesale & retail | 2021 |
| BK Jomanga Ltd | Health & social care | 2023 |
| BK Rugby Ltd | Real estate | 2024 |
| BKB Resources Limited | Administrative & support | 2007 |
| Bklover Ltd | Wholesale & retail | 2024 |
| Bkty Ltd | Wholesale & retail | 2020 |
| Blaby Skip Hire Ltd | Water & waste | 2006 |
| Blackroche Ltd | Health & social care | 2014 |
| Blackwood Buildings Limited | Construction | 2012 |
| Blaine Nissen Vintners Ltd | Wholesale & retail | 2022 |
| Blakes Property Services Limited | Real estate | 2015 |
| Blanc Aero Industries UK Limited | Manufacturing | 1979 |
| Blanccafe Ltd | Hospitality | 2025 |
| Blaze Hair Ltd | Other services | 2020 |
| Blaze Strategic Advisors Limited | Professional & scientific | 2024 |
| Blazej Delivery Ltd | Transport & logistics | 2022 |
| Blazek Ltd | Information & communication | 2014 |
| Blbb Consulting Limited | Water & waste | 2016 |
| Blekoo Ltd | Manufacturing | 2026 |
| BLF Services Ltd | Wholesale & retail | 2025 |
| Blossom Beauty Limited | Health & social care | 2014 |
| BLS Logistics Ltd | Transport & logistics | 2024 |
| Blue Diamond Construction Limited | Construction | 2014 |
| Blue Haze Properties Limited | Real estate | 2002 |
| Blue Moon Home Support Services Limited | Health & social care | 2021 |
| Blue Sky Joinery Limited | Manufacturing | 2013 |
| Blue Sun AC Limited | Manufacturing | 2020 |
| Bluebell Land & Property Ltd | Real estate | 2020 |
| Bluecode Labelling Technology Limited | Manufacturing | 1998 |
| Blueroot Finance Ltd | Professional & scientific | 2025 |
| Blues Sky Transport Limited | Transport & logistics | 2023 |
| Bluesky Sports Finance Ltd | Professional & scientific | 2024 |
| Blythe's Cleaning Services Limited | Administrative & support | 2026 |
| BM Cargo Limited | Transport & logistics | 2018 |
| BM Inter Trans Ltd | Transport & logistics | 2025 |
| Bm&Dd Services Ltd | Construction | 2024 |
| BMI Proactive Services Ltd | Extraterritorial | 2022 |
| Bmls Projects Ltd | Wholesale & retail | 2024 |
| BMR Measurement Solutions Ltd | Professional & scientific | 2020 |
| BMS Drylining Ltd | Construction | 2020 |
| BMS Logistics Ltd | Transport & logistics | 2018 |
| BNR Engineering Limited | Wholesale & retail | 2003 |