| Blue Bridge Property Maintenance Ltd | Construction | 2019 |
| Blue Bridge Property Services LLP | | 2018 |
| Blue Diamond Care Services Ltd | Health & social care | 2024 |
| Blue Diamond Properties Ltd | Health & social care | 2000 |
| Blue Harbour Stays Ltd | Hospitality | 2026 |
| Blue Planet Property Ltd | Real estate | 2024 |
| Blue Print Projects (Kent) Limited | Professional & scientific | 2017 |
| Blueberry Wellbeing Ltd | Health & social care | 1979 |
| Blueline Recruitment Ltd | Administrative & support | 2026 |
| Blueprint Casting Ltd | Information & communication | 2020 |
| Blueprint Houses Ltd | Real estate | 2022 |
| Bluestone Publishing Limited | Information & communication | 1999 |
| Blur Studio Ltd | Information & communication | 2015 |
| BNR Services Ltd | Manufacturing | 2020 |
| Bobbies Bakehouse Limited | Hospitality | 2021 |
| Bodhi Path CIC | Professional & scientific | 2025 |
| Bold Monthly Limited | Information & communication | 2025 |
| Boleyn ST Limited | Construction | 2016 |
| BON Marketing Business Solutions Ltd. | Administrative & support | 2016 |
| Bookmy Holidays Ltd | Transport & logistics | 2026 |
| Boost Brothers ECU & TCU Remapping Limited | Wholesale & retail | 2023 |
| Bootwash Limited | Administrative & support | 2021 |
| Borderline Creatives Ltd | Information & communication | 2023 |
| Borgetti Property Limited | Real estate | 2023 |
| Borough Green Junior FC Limited | Arts & recreation | 2014 |
| Bossingham Groundworks & Landscaping Ltd | Construction | 2013 |
| Boundary Metalstock Limited | Wholesale & retail | 2014 |
| Bouverie Mansions Folkestone Limited | Households | 2025 |
| Bouverie Property Management RTM Company Limited | Households | 2020 |
| Bouverie Square Limited | Real estate | 2018 |
| Bouverieestates Ltd | Real estate | 2026 |
| Boxit Packaging Limited | Wholesale & retail | 2013 |
| Boxwood Business Services Limited | Extraterritorial | 2002 |
| BOY Beech Designs Ltd | Professional & scientific | 2019 |
| Bozyel Construction Ltd | Construction | 2026 |
| BPF Art Projects Ltd | Professional & scientific | 2026 |
| BPH Productions Limited | Professional & scientific | 2006 |
| BPM Formwork Specialists Ltd | Construction | 2009 |
| Bradley Classic Furniture Limited | Manufacturing | 2014 |
| Bradley Furniture Limited | Water & waste | 1982 |
| Bragg Quality Consultancy Limited | Administrative & support | 2007 |
| Brain Frog Nootropics Ltd | Manufacturing | 2026 |
| Brandon Bay Limited | Hospitality | 2002 |
| Bravo Team Engineering Ltd | Professional & scientific | 2022 |
| Breadheads Brothers Limited | Hospitality | 2025 |
| Brew Foods Ltd | Hospitality | 2015 |
| Bridgefield Control Ltd | Extraterritorial | 2007 |
| Bridgepoint Project CIC | Real estate | 2026 |
| Bright Idea Electrical Services Ltd. | Construction | 2011 |
| Brightstar GAS Services Limited | Construction | 2015 |
| Bristol Auction Rooms Limited | Wholesale & retail | 2015 |
| Britflicks Ltd | Extraterritorial | 2010 |
| Broad Oaks Residents Limited | Households | 1992 |
| Broadfield Medical Limited | Health & social care | 2022 |
| Broadstreet House Limited | Health & social care | 1993 |
| Broadsword Finance Ltd | Professional & scientific | 2023 |
| Brockman (Folkestone) Limited | Administrative & support | 1995 |
| Brod Paul Health Safety & Fire Consultancy Limited | Other services | 2016 |
| Broer Estates Limited | Real estate | 2012 |
| Bromleylofts Ltd | Construction | 2025 |
| Brompton Haus Ltd | Manufacturing | 2022 |
| Bronwin Property Management Limited | Professional & scientific | 2002 |
| Bronzone Limited | Other services | 2003 |
| Brookeleefilms Ltd | Information & communication | 2023 |
| Brooks Brickwork and Building Contractors Limited | Construction | 2020 |
| Browns Construction Ltd | Construction | 2015 |
| Browns Real Estate (S.E.) Limited | Real estate | 2017 |
| Browns Realty Ltd | Real estate | 2017 |
| Brsa Master Thatchers Limited | Construction | 2012 |
| Brumley Group Ltd | Construction | 2025 |
| Brummell Resourcing Ltd | Administrative & support | 2021 |
| Brunch & Barrel by Jonathan Finn Limited | Hospitality | 2025 |
| Brushworks Painting and Decorating Ltd | Construction | 2023 |
| Bryant & Simpson Contracting Limited | Other services | 2020 |
| BSG Courier Services Limited | Transport & logistics | 2016 |
| Bsides Kent C.I.C. | Information & communication | 2024 |
| BST Heat Design Limited | Professional & scientific | 2009 |
| Bucket & Spade Limited | Hospitality | 2010 |
| Buckingham Covers Ltd | Extraterritorial | 1999 |
| Buckle UP Films Ltd | Information & communication | 2016 |
| Buckleys (Uvral) Limited | Manufacturing | 1942 |
| Bucknell Ltd | Other services | 2025 |
| Buddha Developments Limited | Construction | 2013 |
| Buddies Rail Ltd | Other services | 2023 |
| Budgetworks Limited | Information & communication | 2005 |
| Buildcertification Ltd | Construction | 2025 |
| Builder's Mate Group Limited | Information & communication | 2024 |
| Buildtude Solutions Ltd | Construction | 2024 |
| Buractimm Limited | Other services | 1992 |
| Burley Court Castle Hill Company Limited | Administrative & support | 2009 |
| Burlington Holdings Hotel Limited | Hospitality | 2018 |
| Burnap + Abel Ltd | Real estate | 2015 |
| Burnetts Fish and Chips Limited | Hospitality | 2026 |
| Burrito Buoy Bar Ltd | Hospitality | 2023 |
| Burrito Buoy Ltd | Wholesale & retail | 2022 |
| Bushells Motorsport Limited | Wholesale & retail | 2022 |
| BUSHIDOSHOTOKANKARATE17 Limited | Arts & recreation | 2018 |
| Business of Art Limited | Arts & recreation | 2019 |
| Buzzaway Limited | Transport & logistics | 2017 |
| BVO Ltd | Other services | 2021 |