| Blackstone Distribution Limited | Wholesale & retail | 2025 |
| Blackstone Global Developments Limited | Construction | 2021 |
| Blackstone Holdings & Investments 2 Ltd | Real estate | 2024 |
| Blackstone Holdings & Investments Limited | Real estate | 2012 |
| Blackstone Home Renovations Ltd | Construction | 2024 |
| Blackstone Law Chambers Ltd | Professional & scientific | 2026 |
| Blackstone Protection Limited | Hospitality | 2026 |
| Blackstone Support and Services Limited | Health & social care | 2023 |
| Blackstory Partnership C.I.C. | Education | 2020 |
| Blackswan Property Limited | Extraterritorial | 2012 |
| Blackthorn (Crowle) Management Company Limited | Households | 2026 |
| Blackthorn House Management Company Limited | Real estate | 2022 |
| Blackwall Brothers Limited | Real estate | 2024 |
| Blackwall Properties Limited | Hospitality | 2021 |
| Blackwell Apparel Ltd | Wholesale & retail | 2025 |
| Blackwell Convenience Store Ltd | Wholesale & retail | 2025 |
| Blackwell Montessori Nursery Limited | Health & social care | 2013 |
| Blackwood Housing Limited | Health & social care | 2020 |
| Blackwood Legal Ltd | Administrative & support | 2025 |
| Blackwood Trading Ltd | Wholesale & retail | 2025 |
| Blactie Supply Limited | Wholesale & retail | 2026 |
| Bladder Health UK Limited | Health & social care | 2012 |
| Blade Farming Limited | Manufacturing | 2003 |
| Blade Gamer Limited | Manufacturing | 2025 |
| Bladeshield Ltd | Wholesale & retail | 2025 |
| Blaid Electrical Services Ltd | Construction | 2014 |
| Blairs Outreach Centre CIC | Education | 2022 |
| Blak Limited | Transport & logistics | 2022 |
| Blake & Co Estates Ltd | Real estate | 2024 |
| Blake Locums Ltd | Health & social care | 2021 |
| Blake Property Development Ltd | Real estate | 2020 |
| Blake Services Ltd | Transport & logistics | 2020 |
| Blake Street Limited | Construction | 2019 |
| Blake Transport Company 0803 Ltd | Transport & logistics | 2025 |
| Blakedown Holdings Ltd | Financial services | 2020 |
| Blakeland Support Services Ltd | Health & social care | 2019 |
| Blakeley Contracts Limited | Real estate | 2002 |
| Blakeney Flats Limited | Households | 2016 |
| Blakesley Mews (1-23) RTM Company Limited | Households | 2022 |
| Blakesley Mews (24-50) RTM Company Limited | Households | 2022 |
| Blakesley Property Group Ltd | Real estate | 2025 |
| Blana Paraiso Limited | Real estate | 2015 |
| Blanc NRI Bham Limited | Hospitality | 2022 |
| Blanca Manuela Ltd | Hospitality | 2023 |
| Blanca Trading Ltd | Administrative & support | 2022 |
| Blanckalture Ltd | Wholesale & retail | 2026 |
| Bland Miscellaneous Limited | Administrative & support | 2018 |
| Blank Slate Cleans Limited | Administrative & support | 2026 |
| Blank Space Operations Limited | Hospitality | 2021 |
| Blanket Media West Midlands Ltd | Professional & scientific | 2023 |
| Blankproducts Limited | Wholesale & retail | 2008 |
| Blantyre Limited | Households | 1993 |
| Blaoui Property Services Ltd | Hospitality | 2021 |
| Blasey Logistics 888 Limited | Transport & logistics | 2017 |
| Blast Fest Ltd | Professional & scientific | 2019 |
| Blast Hygiene Ltd | Construction | 2020 |
| Blast Ituk Ltd | Manufacturing | 2016 |
| Blatchington Eleven Limited | Extraterritorial | 1971 |
| Blathi Supportive Housing Ltd | Real estate | 2025 |
| Blatonite Limited | Administrative & support | 2019 |
| Blaucomm Ltd | Wholesale & retail | 2025 |
| Blaupunkt Ltd | Professional & scientific | 2013 |
| Blawi Trades Ltd | Wholesale & retail | 2025 |
| Blaze Design Group Ltd | Professional & scientific | 2022 |
| Blaze Metals Resources UK Ltd | Wholesale & retail | 2024 |
| Blaze N Bites Limited | Hospitality | 2023 |
| Blaze of Glory Limited | Public administration | 2025 |
| Blaze Security Ltd | Administrative & support | 2019 |
| Blazeboxx Ltd | Hospitality | 2025 |
| Blazin Burgers UK Ltd | Hospitality | 2024 |
| BLD BRO Ltd | Wholesale & retail | 2021 |
| BLD Installations Limited | Manufacturing | 2014 |
| Bledi 5353 Limited | Hospitality | 2017 |
| Bledi Builders Limited | Construction | 2021 |
| Bleebloo Services Ltd | Administrative & support | 2023 |
| Bleen Ltd | Hospitality | 2024 |
| Bleepus Technologies Ltd | Information & communication | 2022 |
| Blemish IO Ltd | Administrative & support | 2016 |
| Blend 91 Ltd | Hospitality | 2025 |
| Blend Formulations Ltd | Wholesale & retail | 2025 |
| Blended Flavour Ltd | Hospitality | 2020 |
| Blendofcultureafricana Ltd | Hospitality | 2024 |
| Blenducate Limited | Education | 2016 |
| Blenheim Services Ltd. | Hospitality | 2010 |
| Blenkinsop Consulting Limited | Professional & scientific | 2013 |
| Blesel Services Limited | Other services | 2020 |
| Blessed Community Care Ltd | Health & social care | 2023 |
| Blessed Drinks & Bites Ltd | Manufacturing | 2025 |
| Blessed Grace Ltd | Health & social care | 2017 |
| Blessed Heart UK Ltd | Health & social care | 2022 |
| Blessed Property Management Limited | Real estate | 2024 |
| Blessed Provision Care Limited | Health & social care | 2014 |
| Blessing Shop Ltd | Wholesale & retail | 2025 |
| Blessing Supermarket Ltd | Wholesale & retail | 2018 |
| Blessings Property Limited | Real estate | 2021 |
| Blesst Ltd | Education | 2018 |
| Bleu Ceramics Ltd | Construction | 2022 |
| Blewbellz Ltd | Wholesale & retail | 2025 |
| Blind 4 Less Ltd | Wholesale & retail | 2022 |
| Blind Arena Ltd | Information & communication | 2025 |