| BKR Properties Ltd | Real estate | 2022 |
| Bkso Limited | Professional & scientific | 2020 |
| Blaauwberg Freight Management Limited | Transport & logistics | 2026 |
| Black Beauty Elite Limited | Wholesale & retail | 2023 |
| Black Bird Chauffeurs Ltd | Transport & logistics | 2019 |
| Black Diamond Furniture Ltd | Other services | 2026 |
| Black Diamond Music Records Limited | Arts & recreation | 2019 |
| Black Hawk Holdings Limited | Other services | 2021 |
| Black Pearl Global Investments Ltd | Mining & quarrying | 2021 |
| Black Star Fleet Ltd | Wholesale & retail | 2026 |
| Blackdown Business Park Ltd | Real estate | 2023 |
| Blacksheep AI Limited | Professional & scientific | 2018 |
| Blaze Mobile Accessories Ltd | Wholesale & retail | 2009 |
| Bless Construction Ltd | Construction | 2021 |
| Blessora Properties Ltd | Real estate | 2026 |
| Bling Bling UK Ltd | Wholesale & retail | 2015 |
| Blinkbuy Store Ltd | Real estate | 2024 |
| Blissful Travels Limited | Administrative & support | 2025 |
| Blissfulselections Ltd | Wholesale & retail | 2022 |
| Blocc Build Limited | Construction | 2015 |
| BLOCKBUILDERS-4 Ltd | Wholesale & retail | 2025 |
| Blocq Tech Limited | Information & communication | 2026 |
| Bloom Hive Limited | Construction | 2025 |
| Blooms Plants & Flowers Ltd | Wholesale & retail | 2023 |
| Blossom Avenue Ltd | Health & social care | 2019 |
| Blossom Hair and Beauty PVT Ltd | Other services | 2021 |
| BLU Haven Care Ltd | Public administration | 2021 |
| BLU Star Fabric Limited | Wholesale & retail | 2019 |
| Blue Dolphin Management Ltd | Health & social care | 2023 |
| Blue DOT Consulting England Ltd | Information & communication | 2025 |
| Blue Horse Transportation Limited | Construction | 2021 |
| Blue Lake Real Estate Ltd | Real estate | 2026 |
| Blue Line Equity Group Ltd | Real estate | 2025 |
| Blue Lion Construction Group Ltd | Construction | 2025 |
| Blue Lion Consultants Ltd | Professional & scientific | 2016 |
| Blue Loft Construction Ltd | Construction | 2019 |
| Blue Lotus Investments Limited | Real estate | 2023 |
| Blue Lotus London Ltd | Real estate | 2021 |
| Blue Mantle Line Ltd | Wholesale & retail | 2020 |
| Blue Pacific Property Limited | Real estate | 2025 |
| Blue Richmond Ltd | Professional & scientific | 2005 |
| Blue Rock Capital Ltd | Real estate | 2024 |
| Blue Saffron Trading Limited | Transport & logistics | 2005 |
| Blue Star Company 786 Ltd | Other services | 2007 |
| Blue Star Enterprises Ltd | Wholesale & retail | 2024 |
| Blue Tide Technologies Ltd | Wholesale & retail | 2024 |
| Blue Wave Novelties Ltd | Wholesale & retail | 2026 |
| Blueaxis Logistics Limited | Transport & logistics | 2024 |
| Bluecart Courier Service Limited | Transport & logistics | 2025 |
| Blueprint & Beyond Ltd | Construction | 2024 |
| Bluestar Investment Ltd. | Financial services | 2012 |
| Bluewater London Ltd | Transport & logistics | 2022 |
| Bluewater Property Consultancy Services Limited | Real estate | 2013 |
| Bluewave Logistics Limited | Transport & logistics | 2026 |
| Bluewaves Systems Limited | Construction | 2026 |
| Blush Accessories London Ltd | Wholesale & retail | 2021 |
| Blush Hair and Beauty Limited | Other services | 2017 |
| BM Exotics Ltd | Wholesale & retail | 2018 |
| BMK Fashion Limited | Wholesale & retail | 2014 |
| BMP Creation Ltd | Wholesale & retail | 2025 |
| BNR Investments Ltd | Administrative & support | 2017 |
| BOB Heating & Plumbing Ltd | Construction | 2021 |
| Bobby Mobile Shop Ltd | Other services | 2019 |
| Bobby One(Uk) Limited | Wholesale & retail | 2023 |
| Bobby Property Ltd | Real estate | 2015 |
| Boca Developments Limited | Construction | 2016 |
| Boeing Way Self Storage Limited | Transport & logistics | 2017 |
| BOL HAR Naam Kirtan Ltd | Other services | 2026 |
| Bold Constructions(London) Ltd | Construction | 2025 |
| Bolton Holidays Limited | Administrative & support | 2026 |
| Bond Street Aesthetics Limited | Health & social care | 2025 |
| Book Savers Ltd | Professional & scientific | 2009 |
| Bookkeepingplus Ltd | Administrative & support | 2012 |
| Books for London Ltd | Professional & scientific | 2012 |
| Bookworm Education Ltd | Education | 2025 |
| Boom HIT Property Ltd | Construction | 2024 |
| Boopal Ltd | Wholesale & retail | 2025 |
| Boothferry Food & Wine Ltd | Wholesale & retail | 2026 |
| Bopar Limited | Real estate | 2019 |
| Boss Estates Ltd | Real estate | 2018 |
| Bowline Wines UK Ltd | Wholesale & retail | 2024 |
| Box 2 Light Ltd | Construction | 2024 |
| BOX2WIGHT Ltd | Construction | 2025 |
| BP FBA Ltd | Wholesale & retail | 2024 |
| BPB Property Group Limited | Real estate | 2017 |
| BPG 3 Ltd | Real estate | 2023 |
| Bpgm Limited | Real estate | 2023 |
| Bpssuns Foods Ltd | Hospitality | 2026 |
| Bradberry Estates Ltd. | Real estate | 2010 |
| Braham Transport Ltd | Transport & logistics | 2026 |
| Brand Britannia Limited | Wholesale & retail | 2025 |
| Brand for ALL Limited | Wholesale & retail | 2023 |
| Brand Geeks Ltd | Professional & scientific | 2023 |
| Brandever Limited | Professional & scientific | 2006 |
| Brands Realtor Ltd | Real estate | 2020 |
| Brandseeder Ltd | Information & communication | 2022 |
| Bravex Ltd | Wholesale & retail | 2026 |
| BRC & Sons Limited | Other services | 2020 |
| BRD Trader Ltd | Construction | 2026 |
| Bread Spread Limited | Hospitality | 2018 |