| Bhuller Property Investment Ltd | Real estate | 2022 |
| BI Migration Technologies Ltd | Information & communication | 2026 |
| BIA Transport Ltd | Transport & logistics | 2019 |
| Bibi Dhillon Ltd | Hospitality | 2026 |
| Bibi Supermarket Limited | Wholesale & retail | 2022 |
| Biddium Ltd | Wholesale & retail | 2026 |
| Bide Projects Ltd | Other services | 2024 |
| Bideshchamling Ltd | Real estate | 2025 |
| Big Bar Limited | Wholesale & retail | 2023 |
| Big Boss Food & Wine Limited | Wholesale & retail | 2013 |
| Big BOY Pizza Delivery Limited | Hospitality | 2010 |
| Big BOY Pizzeria Ltd | Hospitality | 2025 |
| Big Brand in Hand Ltd | Wholesale & retail | 2025 |
| Big Brothers Investments Ltd | Real estate | 2025 |
| Big Deals Logistics Ltd | Transport & logistics | 2025 |
| Big Ideas London Limited | Wholesale & retail | 2003 |
| Bigg NOW Ltd | Information & communication | 2018 |
| Bighouse Furniture Ltd | Extraterritorial | 2015 |
| Bigview Digital Limited | Professional & scientific | 2026 |
| Bika Properties Limited | Real estate | 2021 |
| Bilal Cars Ltd | Administrative & support | 2025 |
| Bilan Hayes Limited | Wholesale & retail | 2024 |
| Bilan Transport Ltd | Transport & logistics | 2019 |
| Bilen Property Limited | Real estate | 2017 |
| Bilkhu Constructions Ltd | Construction | 2024 |
| Bilsten Builder's Ltd | Construction | 2023 |
| Bilton Food & Wine Ltd | Wholesale & retail | 2018 |
| Bimasa Estates Ltd | Real estate | 2024 |
| Binary Global UK Limited | Information & communication | 2022 |
| Bindiya Trading Ltd | Wholesale & retail | 2021 |
| Bindra Company Ltd | Wholesale & retail | 2024 |
| Bindra Transport Ltd | Transport & logistics | 2018 |
| Binny Films Ltd | Transport & logistics | 2021 |
| Bint Couture Ltd | Wholesale & retail | 2026 |
| Bips UK Ltd | Wholesale & retail | 2013 |
| BIR Design and Build Ltd | Construction | 2025 |
| BIR House Limited | Real estate | 2022 |
| BIR Property Ltd | Real estate | 2021 |
| Birk Investments Ltd | Real estate | 2021 |
| Birk Properties London Ltd | Real estate | 2018 |
| Birk Solutions Limited | Construction | 2016 |
| Birmann Information Technology Ltd | Information & communication | 2024 |
| Birring Services Ltd | Transport & logistics | 2024 |
| Biryani POP Hayes Ltd | Hospitality | 2025 |
| Biryani Spice London Ltd | Hospitality | 2024 |
| Bishnoi Construction Ltd | Construction | 2025 |
| Bismillah Mart Ltd | Wholesale & retail | 2025 |
| Biso's Plumbing and Heating Ltd | Construction | 2025 |
| Bittu Hair Salon Limited | Other services | 2017 |
| Bizztrend Marketing Limited | Wholesale & retail | 2022 |
| BJS Brickwork Limited | Construction | 2025 |
| BK (Whitton) Property Ltd | Real estate | 2021 |
| BKD Haulage Ltd | Transport & logistics | 2026 |
| BKG Property Investments Ltd | Real estate | 2025 |
| BKM Homes Limited | Real estate | 2016 |
| BL Law Chambers Ltd | Professional & scientific | 2018 |
| Black & White Furniture Ltd | Manufacturing | 2024 |
| Black Box Photographic Limited | Professional & scientific | 2006 |
| Black to White Electrical Wholesalers Limited | Manufacturing | 2020 |
| Black to White Plumbing Services Limited | Construction | 2026 |
| Black to White Systems Limited | Construction | 2016 |
| Blackbeard Ltd | Other services | 2013 |
| Blackbite Limited | Construction | 2025 |
| Blackcrest Ltd | Administrative & support | 2026 |
| Blackdot Services Ltd | Administrative & support | 2024 |
| Blacklane Logistics Ltd | Transport & logistics | 2026 |
| Blandings Management Limited | Real estate | 1982 |
| Blaze Global Chauffeurs Ltd. | Transport & logistics | 2026 |
| Bless Fitted Wardrobes & Kitchens Ltd | Manufacturing | 2025 |
| Blessing Property Holdings Ltd | Real estate | 2026 |
| Blessing's Shop Ltd | Health & social care | 2024 |
| Bliss Obscure Ltd | Real estate | 2024 |
| Bliss Transport Services Ltd | Transport & logistics | 2025 |
| Blitzbays Online Marketplace Ltd. | Wholesale & retail | 2025 |
| Bloom House 8A Ltd | Real estate | 2024 |
| Bloomelia Flowers Ltd | Wholesale & retail | 2025 |
| Blossom's Little Explorers Ltd | Health & social care | 2025 |
| BLR Property Sourcing Ltd | Administrative & support | 2024 |
| BLU RAY Ltd | Wholesale & retail | 2022 |
| Blue and Yellow Limited | Real estate | 2021 |
| Blue ARC Constructions Limited | Other services | 2019 |
| Blue Architecture Limited | Professional & scientific | 2011 |
| Blue Collar PAY Solutions Ltd. | Administrative & support | 2019 |
| Blue Eagle Group Ltd | Wholesale & retail | 2024 |
| Blue Flame Solutions Ltd | Construction | 2025 |
| Blue House Invest Limited | Real estate | 2024 |
| Blue Lion Contractors Ltd | Construction | 2022 |
| Blue Lion Luxury Rides Ltd | Transport & logistics | 2025 |
| Blue M Diamond Properties Ltd | Real estate | 2019 |
| Blue Mark Construction Ltd | Construction | 2023 |
| Blue Mark Contractors Ltd | Construction | 2022 |
| Blue Mile Services Ltd | Transport & logistics | 2026 |
| Blue Ocean Cargo Ltd | Transport & logistics | 2025 |
| Blue Ocean Haulage Ltd | Transport & logistics | 2024 |
| Blue Ocean Plastics & Glazing Ltd | Construction | 2012 |
| Blue Ocean Roofing Ltd | Construction | 2024 |
| Blue Osprey Films Limited | Information & communication | 2019 |
| Blue Panther Services Limited | Administrative & support | 2025 |
| Blue Peak Properties Limited | Real estate | 2023 |
| Blue Pheonix Limited | Other services | 2012 |