| BOQ Limited | Other services | 2004 |
| Born for This CIC | Education | 2026 |
| Boston Group UK Limited | Professional & scientific | 2025 |
| Botanical Beverages 2.0 Ltd | Wholesale & retail | 2025 |
| Botmatic Limited | Information & communication | 2017 |
| Bougain Designer Boutique Limited | Wholesale & retail | 2024 |
| Bougainvillea Care Ltd | Health & social care | 2025 |
| Bougainvillea Healthcare Ltd | Health & social care | 2024 |
| Boughton Fisheries Limited | Extraterritorial | 2010 |
| Boughton Hand Car Wash Limited | Administrative & support | 2025 |
| Boundary Fencing & Timber Supplies UK Limited | Wholesale & retail | 2020 |
| Boundary Fencing UK (Kent) Ltd | Construction | 2018 |
| Boundless Love Ltd | Education | 2023 |
| Bourchier Street Management Company Limited | Households | 1997 |
| Bourne Installation Limited | Construction | 2023 |
| Bourne Pipework Services Limited | Construction | 2017 |
| Bourne Property Services Ltd | Construction | 2021 |
| Bournes Consulting LLP | | 2012 |
| Boutonne Ltd | Extraterritorial | 2019 |
| BOW Bridge Marina Limited | Administrative & support | 1995 |
| BOW END Ltd | Real estate | 2024 |
| Bowden Invest Limited | Administrative & support | 2025 |
| Bower Close (Maidstone) Limited | Households | 2011 |
| Bower Cuts Ltd | Other services | 2021 |
| Bower Store Ltd | Wholesale & retail | 2023 |
| Bower Terrace Management Company Limited | Households | 2023 |
| Bowers Pharmaceutical Development Consulting Ltd | Professional & scientific | 2021 |
| Bowley Supplies Ltd | Wholesale & retail | 2025 |
| Box Clever Dubai Holdings Limited | Manufacturing | 2025 |
| Box Crab Digital Limited | Professional & scientific | 2023 |
| Box Verte Limited | Financial services | 2018 |
| Boxcat Ltd | Arts & recreation | 2019 |
| Boxcat Studio Limited | Arts & recreation | 2018 |
| Boxharry Ltd. | Information & communication | 2002 |
| Boxing in Schools Ltd | Education | 2022 |
| Boxley Developments Limited | Construction | 2014 |
| Boxley Minimarket Limited | Wholesale & retail | 2021 |
| Boxley Timber & Fencing Supplies Limited | Manufacturing | 1997 |
| Boxley Wealth Management Ltd | Financial services | 2021 |
| Boyer-Bransden Electronics Limited | Manufacturing | 1972 |
| Boyle DRY Cleaning Limited | Other services | 2015 |
| Bozmac Limited | Professional & scientific | 2017 |
| BP Nursery Photos Limited | Professional & scientific | 2013 |
| BPE Specialised Drillings Limited | Construction | 2000 |
| BPO Ltd | Administrative & support | 2016 |
| BR Lifts Ltd | Manufacturing | 2022 |
| Br-Elec Services Limited | Financial services | 2023 |
| BRA Utilities Limited | Energy | 2026 |
| Brachers Company Services Limited | Professional & scientific | 1988 |
| Brachers Credit Management Services Limited | Professional & scientific | 1996 |
| Brachers LLP | | 2008 |
| Brachers Nominees Limited | Professional & scientific | 1991 |
| Brachers Pension Trustee Limited | Professional & scientific | 1999 |
| Brachers Properties Limited | Professional & scientific | 2002 |
| Brachers Trust Corporation Limited | Administrative & support | 2014 |
| Bracken Creative Limited | Other services | 2023 |
| Brackfield Holdings Ltd | Financial services | 2024 |
| Brackfield Limited | Transport & logistics | 2001 |
| Brackley Transport Ltd | Transport & logistics | 2022 |
| Brad Brooks Ltd | Construction | 2014 |
| Brad King Scaffolding Ltd | Construction | 2026 |
| Bradbeam Limited | | 1990 |
| Bradbourne Publishing Limited | Information & communication | 1995 |
| Brainloop Digital Services Limited | Information & communication | 2025 |
| Brainstorm Properties Limited | Real estate | 2003 |
| Braiseworth Ltd | Information & communication | 2019 |
| Braithwaite Enterprises Limited | Professional & scientific | 2025 |
| Brambledown (Kent) Ltd | Wholesale & retail | 2010 |
| Bramley Court (Bedfont) Residents Association Limited | Real estate | 1995 |
| Brand Journeys Ltd | Professional & scientific | 2014 |
| Brand Loom Marketing Ltd | Professional & scientific | 2025 |
| BRANDX2 Limited | Administrative & support | 2023 |
| Brandy's Bay Management Company Limited | Households | 2017 |
| Bransden Electronics Limited | Manufacturing | 1971 |
| Braumont Limited | Administrative & support | 1984 |
| Brave Ladies of Kent Limited | Wholesale & retail | 2024 |
| Bravo Products Ltd | Wholesale & retail | 2022 |
| Braxted Crescent Management Company Limited | Real estate | 2016 |
| Bray & SON Limited | Transport & logistics | 2001 |
| Brayshaw & Dimmer Events Ltd | Hospitality | 2026 |
| BRC Mobile Mechanic Ltd | Wholesale & retail | 2024 |
| Brecani Holdings Ltd | Financial services | 2025 |
| Breitengrad Consult. Limited | Administrative & support | 2011 |
| Brenchley Fields Management Limited | Households | 2024 |
| Brend Building Surveyors Ltd | Professional & scientific | 2023 |
| Brendan Mills Music Limited | Arts & recreation | 2016 |
| Brendan White Private Chef Ltd | Hospitality | 2025 |
| Brenna Capital Ltd | Financial services | 2025 |
| Bretland House Limited | Households | 2002 |
| Bretstone Accountants Limited | Professional & scientific | 2022 |
| Briant Properties Limited | Real estate | 2024 |
| Briant Traffic Limited | Construction | 2017 |
| Brick by Brick Construction and Landscape Ltd | Construction | 2022 |
| Brickfield Leisure Ltd | Agriculture & fishing | 2024 |
| Bricknell Investments Limited | Other services | 2022 |
| Bricks Solutions Ltd | Construction | 2025 |
| Bricktile Ltd | Construction | 2009 |
| Brickwall Estates Ltd | Real estate | 2005 |
| Bridgecedar Limited | Households | 2005 |
| Bridgehouse Properties Development Limited | Construction | 2024 |