| Bexley Voluntary Service Council Limited | Health & social care | 1980 |
| Bexley Womens AID | Other services | 1995 |
| Bexleyheath Community Church | Other services | 2012 |
| Beyond Crtv Ltd | Information & communication | 2022 |
| Beyond Learning Ltd | Information & communication | 2019 |
| Beyondchalle Ltd | Administrative & support | 2026 |
| Bfit Personal Training LDN Ltd | Arts & recreation | 2026 |
| BGX Ltd | Administrative & support | 2021 |
| Bhisob Finance & Mortgages Ltd | Financial services | 2024 |
| Bibiranky Fashion and Beauty Limited | Wholesale & retail | 2025 |
| Bibiranky Services Limited | Administrative & support | 2025 |
| Big BEN Education Ltd | Education | 2016 |
| Big Brother Building Services Ltd | Construction | 2019 |
| Big MAN Consultancy Limited | Transport & logistics | 2007 |
| Bigdoo Ltd | Professional & scientific | 2016 |
| Bigmash Ltd | Wholesale & retail | 2015 |
| Biji Consultancy Limited | Real estate | 2023 |
| Billy Brothers Ltd | Construction | 2020 |
| Bimayo Health Care Services Limited | Health & social care | 2013 |
| Bimplymo Ltd | Wholesale & retail | 2022 |
| Biochris Medical Ltd | Health & social care | 2011 |
| Biochris Property Limited | Real estate | 2025 |
| Bioma Ltd | Health & social care | 2022 |
| Bironke Properties Ltd | Real estate | 2024 |
| Bisla Estates Ltd | Real estate | 2017 |
| BK Catering and Entertainment Ltd | Hospitality | 2025 |
| Black Management Services Ltd | Information & communication | 2021 |
| Blackhorse Motors London Limited | Wholesale & retail | 2008 |
| Blacklocust Media Limited | Information & communication | 2014 |
| Bless Bridge Ltd | Health & social care | 2023 |
| Blessed Bridge Ltd | Administrative & support | 2023 |
| Blessingawi Enterprises Limited | Health & social care | 2020 |
| BLI Consultancy Services Ltd | Professional & scientific | 2018 |
| Blissful Care & Consulting Services Ltd | Health & social care | 2020 |
| Blissful Homes Creations Ltd | Construction | 2025 |
| Blissful Wealth Ltd | Real estate | 2025 |
| Blivic Haven Estates Ltd | Real estate | 2025 |
| BLL Holdings Limited | Manufacturing | 1999 |
| Block N Brick Ltd | Construction | 2024 |
| Bloo INK Publishing Limited | Wholesale & retail | 2017 |
| Blossom Havens Limited | Health & social care | 2023 |
| BLS Consultants Ltd | Professional & scientific | 2025 |
| Bltt Business Solutions Ltd. | Professional & scientific | 2016 |
| Blue Collar Construction Ltd | Construction | 2025 |
| Blue Phoenix Developments Limited | Construction | 2021 |
| Blue Phoenix Management Limited | Households | 2022 |
| Bluedove Limited | Transport & logistics | 2018 |
| Bluefield Legacy Limited | Real estate | 2026 |
| Blueskay Residential Homes Limited | Health & social care | 2025 |
| Bluesky Building Services Ltd | Construction | 2025 |
| Bluestar Recycling Limited | Water & waste | 2023 |
| Bluestone Asset Management Ltd | Real estate | 2023 |
| Bluestone Mortgage Solutions Limited | Financial services | 2020 |
| Bluniva Ltd | Wholesale & retail | 2025 |
| BM Trans Logistic Ltd | Transport & logistics | 2023 |
| Bmirt Ltd | Information & communication | 2022 |
| BMM Holdings Limited | Financial services | 2026 |
| BMS Property Ltd | Real estate | 2017 |
| Bn&An Ltd | Construction | 2019 |
| BO Peep Learning Ltd | Information & communication | 2018 |
| Board Properties Limited | Construction | 2017 |
| Bobby(Uk) Ltd | Wholesale & retail | 2022 |
| Bodekcom Limited | Construction | 2012 |
| Body in the City Ltd | Other services | 2021 |
| Bolad Heartland Care Ltd | Health & social care | 2023 |
| Boladel Limited | Real estate | 2013 |
| Bolajordan Ltd | Real estate | 2024 |
| Bolarge Computers Limited | Administrative & support | 2017 |
| BON Homes Ltd | Households | 2018 |
| Bonchurch Contract Services Ltd | Construction | 2015 |
| BOO Care Services Limited | Administrative & support | 2020 |
| Boobito Flore (UK) Limited | Administrative & support | 2022 |
| Bornready Academy Athletics Ltd | Arts & recreation | 2024 |
| Bortlian Homecare Ltd. | Health & social care | 2023 |
| Bospitality Limited | Hospitality | 2023 |
| Bourke & Carter Ltd | Construction | 2023 |
| Box and Van Ltd | Transport & logistics | 2026 |
| Bpal Ltd. | Health & social care | 2018 |
| Bpch Ltd | Construction | 2024 |
| Bpharma Solutions Ltd | Real estate | 2020 |
| Braids by Freda Ltd | Other services | 2024 |
| Branq Studio Ltd | Manufacturing | 2024 |
| Bransell Supported Housing CIC | Hospitality | 2022 |
| Breath of GOD Parish Limited | Other services | 2016 |
| Bricfield Ltd | Construction | 2022 |
| Brick & Willow Limited | Construction | 2017 |
| Brick Built Properties Ltd | Real estate | 2026 |
| Brigabs Ltd | Wholesale & retail | 2019 |
| Bright Future for Crin's Children Limited | Education | 2019 |
| Bright Side Recruitment Ltd | Administrative & support | 2020 |
| Brightshore Immigration Ltd | Professional & scientific | 2025 |
| Brightstone Enterprises Limited | Wholesale & retail | 2025 |
| Brillamax Ltd | Construction | 2025 |
| Brilliart Limited | Construction | 2014 |
| Britknight Electronics Limited | Wholesale & retail | 2025 |
| BRK Logistics Limited | Transport & logistics | 2015 |
| Brols Jshuoik Limited | Wholesale & retail | 2025 |
| Bronzed Tanning & Beauty Ltd | Other services | 2018 |
| Bronzedboutique Ltd | Wholesale & retail | 2022 |
| Brothersima Ltd | Transport & logistics | 2024 |