| Baxter, Avey & Company Limited | Wholesale & retail | 1987 |
| Bayd Cafe Ltd | Hospitality | 2024 |
| Bayswaters Investments Limited | Real estate | 2025 |
| Bayt Property Ventures (UK) Limited | Real estate | 2021 |
| Bayvik Ltd | Information & communication | 2025 |
| BAZ & BAZ Ltd | Real estate | 2022 |
| Bazlol Limited | Hospitality | 2025 |
| BB IT Solutions & Consultancy Ltd | Information & communication | 2025 |
| BB Passive Ltd | Construction | 2026 |
| BB Staff Recruitment Ltd | Administrative & support | 2026 |
| Bb&Pu Limited | Real estate | 2025 |
| BBA MAX Ltd | Hospitality | 2022 |
| BBL Group Holdings Limited | Financial services | 2019 |
| BBL Group Properties Limited | Real estate | 2019 |
| BBQ-12 Limited | Hospitality | 2023 |
| BBR Mastermind Ltd | Administrative & support | 2016 |
| BCC International Limited | Water & waste | 2004 |
| Bcia Holdings Limited | Hospitality | 2024 |
| Bcnmr Consulting Limited | Education | 2022 |
| Bcpm UK Ltd | Construction | 2024 |
| Bcsretail Ltd | Wholesale & retail | 2025 |
| Bcssocial Ltd | Wholesale & retail | 2025 |
| BCW Consultancy Ltd | Real estate | 2017 |
| BCW Trans Ltd | Transport & logistics | 2025 |
| BCW Venture Ltd | Real estate | 2026 |
| BCW1 Holdings Ltd | Financial services | 2025 |
| BD Solicitors Limited | Professional & scientific | 2010 |
| BDH Accountancy Limited | Professional & scientific | 2003 |
| Bdlr Limited | Professional & scientific | 2017 |
| BDX Welding & Fabrication Ltd | Manufacturing | 2025 |
| BE Better Peptides Ltd | Professional & scientific | 2024 |
| BE Forever Grief Group CIC | Education | 2025 |
| BE Home Smart Limited | Administrative & support | 2022 |
| BE Kind Investments Ltd | Real estate | 2021 |
| BE Muudy Ltd | Wholesale & retail | 2023 |
| BE Trade Smart Ltd | Professional & scientific | 2018 |
| BE Well Health and Nutrition Ltd | Wholesale & retail | 2025 |
| BE YOU Health Ltd | Health & social care | 2018 |
| BEA25 Ltd | Transport & logistics | 2025 |
| Beacon Avenue Group Ltd | Information & communication | 2022 |
| Beaconsfield MSA Business Centre Limited | Real estate | 2012 |
| Beaconside Residents Company Limited | Households | 2005 |
| Beam Baking Systems Limited | Manufacturing | 1993 |
| Beanpod Nutrition Ltd | Hospitality | 2022 |
| Beans Coffee Stop Limited | Hospitality | 2003 |
| Bear Business Finance Limited | Financial services | 2017 |
| Bear Commercial Capital Ltd | Professional & scientific | 2026 |
| Bear Guru Property Partners Limited | Real estate | 2019 |
| Bear Gym Equipment Limited | Administrative & support | 2022 |
| Bear Pictures Ltd | Information & communication | 2016 |
| Beat This C.I.C. | Education | 2010 |
| Beataskip Ltd | Wholesale & retail | 2025 |
| Beatrice Brandon Limited | Extraterritorial | 2015 |
| Beatullah Tours Ltd | Wholesale & retail | 2025 |
| Beaudesert and Henley Property Group Ltd | Real estate | 2025 |
| Beaulah House Consulting Limited | Real estate | 2016 |
| Beautiful Aesthetics Ltd | Health & social care | 2021 |
| Beautiful Hanging Baskets (BHB) Limited | Wholesale & retail | 2026 |
| Beautiful Lives CIC | Education | 2024 |
| Beauty 1ST Ltd | Wholesale & retail | 2019 |
| Beauty by Britney Limited | Other services | 2025 |
| Beauty by L&Co Ltd | Administrative & support | 2016 |
| Beauty Delicious Limited | Wholesale & retail | 2020 |
| Beauty Embassy Limited | Other services | 2019 |
| Beauty Lounge Walthamstow Ltd | Other services | 2016 |
| Beauty Scents Ltd | Manufacturing | 2014 |
| Beautyfull Brows Ltd | Other services | 2022 |
| Beaver Commercial Properties Limited | Real estate | 1975 |
| Becki & Claire's Heartfelt Care Ltd | Health & social care | 2025 |
| Bedford Investments Limited | Construction | 2018 |
| Bedfords Markets UK Limited | Administrative & support | 2014 |
| Bedrock Lettings Limited | Real estate | 2021 |
| BEE Green BE Mobile Ltd | Wholesale & retail | 2020 |
| BEE Honey Farm Ltd | Agriculture & fishing | 2023 |
| Bee's Care Home Ltd | Health & social care | 2026 |
| Bee's Care Huntington Ltd | Health & social care | 2026 |
| Bee's Care Limited | Health & social care | 2017 |
| Bee-Ethical Ltd. | Administrative & support | 2014 |
| Beech Court (the Lakes Business Park) Management Company Limited | Real estate | 2022 |
| Beechclub Ltd | Wholesale & retail | 2006 |
| Beechcroft Residents Management Company Limited | Households | 2005 |
| Beecroft House Management Company Limited | Households | 1989 |
| Beel Worldwide Services Ltd | Wholesale & retail | 2025 |
| Bees & Honey Channel Partners Limited | Information & communication | 2025 |
| Bees Holdings Ltd | Real estate | 2024 |
| Beespoke Springs Limited | Health & social care | 2023 |
| Beetrock Limited | Wholesale & retail | 2023 |
| Beetroot Catering at the Barn Ltd | Hospitality | 2024 |
| Beetroot Catering Ltd | Hospitality | 2011 |
| Beez Cuts & Styles Ltd | Other services | 2019 |
| Before&Beyond Ltd | Administrative & support | 2012 |
| Beftonforth Limited | Construction | 1993 |
| Begur Ltd | Professional & scientific | 2016 |
| Begwary 1954 Limited | Extraterritorial | 2013 |
| Behind the Yellow Door Ltd | Hospitality | 2025 |
| Beit EL Transport Ltd | Transport & logistics | 2020 |
| Bejoy's Properties Ltd | Real estate | 2022 |
| BEL Air (Gamston) Limited | Hospitality | 2019 |
| Belfry Facade Systems Limited | Manufacturing | 2017 |
| Belgravia Court Residents Company Limited | Households | 2016 |