| BG Desserts Ltd | Hospitality | 2022 |
| BGA Creative Ltd | Professional & scientific | 2026 |
| Bgbb Motors Limited | Real estate | 2009 |
| Bgop Limited | Health & social care | 2018 |
| BHE Partnership Limited | Professional & scientific | 2016 |
| BHL RTM Company Limited | Households | 2010 |
| BI Avrora Limited | Construction | 2012 |
| Bidborough Court Management Limited | Households | 2001 |
| Big ALP Ltd. | Information & communication | 2003 |
| Big Apricot Ltd | Professional & scientific | 2016 |
| Big Orange Media Ltd | Professional & scientific | 2016 |
| Big Pixel Limited | Information & communication | 2014 |
| Big Red Burn Limited | Construction | 2023 |
| Big Triangle Ltd | Education | 2023 |
| Big Vapes Ltd | Wholesale & retail | 2025 |
| Big White Sail Limited | Information & communication | 2017 |
| Bigwood ,Business and Beyond LLP | | 2024 |
| Billanz Bookkeeping Limited | Professional & scientific | 2024 |
| Billyos Ltd | Households | 2020 |
| Bilsby Chiropractic Limited | Health & social care | 2014 |
| Binary Affairs Ltd | Administrative & support | 2015 |
| Binary Management Limited | Other services | 1994 |
| Binks Associates Ltd | Professional & scientific | 2014 |
| Bintang Baru Associates Limited | Administrative & support | 2007 |
| Biocare Health Ltd | Manufacturing | 2019 |
| Birational Ltd | Professional & scientific | 2024 |
| Birchetts Avenue (Management) Company Limited | Households | 1986 |
| Bircholme Properties Limited | Households | 2024 |
| Birchward Ltd | Wholesale & retail | 2021 |
| Bird & Wolf Ltd | Professional & scientific | 2025 |
| Bird Groundworks & Demolition Ltd | Construction | 2014 |
| Birdham Properties Limited | Real estate | 1958 |
| Birdineye Farm LLP | | 2018 |
| Birgit Holistic VET Ltd | Professional & scientific | 2015 |
| Birling Agencies Ltd | Wholesale & retail | 2019 |
| Birty Consulting Ltd | Construction | 2023 |
| Biruni Limited | Professional & scientific | 2018 |
| Bishop's Field (Maidstone) Management Co. Ltd. | Households | 2007 |
| Bishops and Clerks Ltd | Financial services | 2025 |
| Bishops Court Residents Association Limited | Households | 1991 |
| Bishops Down Park Road (East) Limited | Households | 1996 |
| Bishops Down Park Road (West) Limited | Households | 2017 |
| Bishopscroft Management Company Limited | Households | 1981 |
| Bishprop Ltd | Real estate | 2013 |
| Bitroot Ltd | Information & communication | 2025 |
| BIZ Relic Property Ltd | Real estate | 2023 |
| Bizcommerce Ltd | Wholesale & retail | 2025 |
| BJ Electronics Ltd | Administrative & support | 2009 |
| BJC Property Management Limited | Real estate | 2022 |
| BLA2EX Limited | Other services | 2023 |
| Black & Even Ltd | Other services | 2015 |
| Black Barn Group Ltd | Real estate | 2019 |
| Black Book Production Ltd | Professional & scientific | 2017 |
| Black BUG Creative Ltd | Administrative & support | 2014 |
| Black CAP Consultancy Ltd | Professional & scientific | 2025 |
| Black Deer Ltd | Construction | 2025 |
| Black Panther Transport Ltd | Transport & logistics | 2023 |
| Black Portfolio Limited | Real estate | 2019 |
| Black Research Laboratories Ltd | Manufacturing | 2026 |
| Blackbird Heating and Plumbing Ltd | Construction | 2020 |
| Blackfin Limited | Extraterritorial | 2017 |
| Blackheath Asset Management Limited | Construction | 2005 |
| Blackhurst Park Limited | Real estate | 2004 |
| Blackrock Search Limited | Professional & scientific | 2009 |
| Blackthrone Limited | Professional & scientific | 2012 |
| Blackthrone Ventures Limited | Real estate | 2025 |
| Blackwood Carpentry & Joinery Ltd | Construction | 2021 |
| Blackwood Design & Build Ltd | Construction | 2026 |
| Bladerunners (Kent) Ltd | Other services | 2016 |
| Blank Canvas [Publishing] Limited | Information & communication | 2002 |
| Blanket Sound Ltd | Information & communication | 2019 |
| Blasto-Box.Uk Limited | Administrative & support | 2024 |
| Blazar Ltd | Professional & scientific | 2022 |
| Blaze Maintenance Limited | Manufacturing | 1983 |
| BLC Digital Limited | Information & communication | 2014 |
| Blended Bars Ltd | Hospitality | 2025 |
| Bleu Rose Aesthetics Ltd | Other services | 2021 |
| Blirb Broadcasting Ltd | Information & communication | 2021 |
| Blish Ltd | Information & communication | 2021 |
| Bloc IQ Ltd | Information & communication | 2025 |
| Blok Blok Energy Ltd | Information & communication | 2022 |
| Blowup Holding Ltd | Information & communication | 2021 |
| BLU Build Construction Ltd | Construction | 2024 |
| Blucube Limited | Information & communication | 2005 |
| Blue Bricks and Mortar Limited | Real estate | 2018 |
| Blue Dental Laboratory Limited | Health & social care | 2015 |
| Blue Dragonfly Ltd | Administrative & support | 2010 |
| Blue Heat Service Ltd | Construction | 2024 |
| Blue Herald Limited | Administrative & support | 2011 |
| Blue Hippo Advisory Ltd | Professional & scientific | 2025 |
| Blue Light Internet Limited | Information & communication | 2009 |
| Blue Line Adventures Limited | Arts & recreation | 2026 |
| Blue Mark Books Limited | Information & communication | 2013 |
| Blue Mountain Recruitment Ltd | Administrative & support | 2007 |
| Blue Rabbit Creative Limited | Information & communication | 2006 |
| Blue Rhapsody Limited | Administrative & support | 1996 |
| Blue Taurus Ltd | Professional & scientific | 2019 |
| Blue Zulu Consultancy Limited | Financial services | 2008 |
| Bluebird Plumbing & Heating Ltd | Construction | 2018 |
| Bluebox Worldwide Ltd | Information & communication | 2008 |