| Body Matters Beauty Limited | Other services | 2002 |
| Body Matters MK Ltd | Other services | 2023 |
| Boiled Rice Limited | Information & communication | 2025 |
| Bombay Racing Limited | Arts & recreation | 2022 |
| Bonomo-Fox Aviation Services Limited | Information & communication | 2012 |
| Boost Lifestyle Ltd | Other services | 2020 |
| Boosted Plus Ltd | Professional & scientific | 2021 |
| Borchester Property Management Ltd | Real estate | 2013 |
| Bored Blast Ltd | Information & communication | 2025 |
| Born Urban Barbers 2 Limited | Other services | 2018 |
| Born Urban Barbers Limited | Other services | 2016 |
| BOT Investments Limited | Real estate | 2024 |
| Boundary Space Limited | Professional & scientific | 2010 |
| Bowsey Holdings Ltd | Hospitality | 2024 |
| Box League Ltd | Arts & recreation | 2025 |
| Boxhill Solutions Limited | Other services | 2014 |
| BPM RPM Ltd | Administrative & support | 2024 |
| Brackley Road (Buckingham) Management Company Limited | Households | 2003 |
| Bradbury Outdoor Spaces Ltd | Extraterritorial | 2023 |
| Brady Construction Ltd | Construction | 2016 |
| Brainwave AI Limited | Information & communication | 2017 |
| Bramble Stud Ltd | Agriculture & fishing | 2025 |
| Brandon Business and Management Services Ltd | Professional & scientific | 2024 |
| Brave Roots Ltd | Education | 2018 |
| BRD Builders Limited | Energy | 2014 |
| Breaking Good Ltd | Information & communication | 2016 |
| Brick by Brick Digital Ltd | Professional & scientific | 2025 |
| Bridge Street Flooring Limited | Wholesale & retail | 2010 |
| Bridson Limited | Professional & scientific | 2023 |
| Brightwork Builders Limited | Construction | 2025 |
| Brillbury Care Ltd | Professional & scientific | 2026 |
| Brillbury Limited | Health & social care | 2026 |
| Brillgardens Ltd | Professional & scientific | 2024 |
| British Honey Producers Limited | Manufacturing | 1995 |
| Brits Smart Homes Ltd | Real estate | 2018 |
| Brocksmith Scientific Ltd | Professional & scientific | 2003 |
| Brodie Consulting Group Ltd | Professional & scientific | 2019 |
| Broughton Beatty Wearring Ltd | Administrative & support | 2014 |
| Brunner Place Residents Limited | Households | 2003 |
| Brunton Consultancy Limited | Professional & scientific | 2005 |
| BTB Contracts Limited | Construction | 2009 |
| BTG Construction (Yorkshire) Limited | Construction | 2025 |
| BTJ Watches Limited | Wholesale & retail | 2018 |
| Bubbles and Boards Ltd | Hospitality | 2025 |
| Buckingham Boxing Club CIC | Education | 2024 |
| Buckingham Business Solutions Ltd | Professional & scientific | 2017 |
| Buckingham Car Storage Limited | Administrative & support | 2010 |
| Buckingham CCA Limited | Other services | 2015 |
| Buckingham Clothes CIC | Wholesale & retail | 2025 |
| Buckingham Commercial Holdings Limited | Real estate | 2019 |
| Buckingham Commercial Sales Ltd | Wholesale & retail | 2016 |
| Buckingham Fish and Chips Bar Limited | Hospitality | 2018 |
| Buckingham Fish Bar Limited | Hospitality | 2022 |
| Buckingham Flooring Holdings Limited | Financial services | 2023 |
| Buckingham Flooring Limited | Wholesale & retail | 1996 |
| Buckingham Garden Centre Ltd. | Wholesale & retail | 2010 |
| Buckingham Glass Ltd | Construction | 2010 |
| Buckingham Golf Club Limited | Arts & recreation | 2014 |
| Buckingham Home Care Limited | Health & social care | 2014 |
| Buckingham House Rentals Limited | Real estate | 2024 |
| Buckingham Hydrocarbon Services Limited | Administrative & support | 2007 |
| Buckingham Islamic Welfare Association (Biwa) | Education | 2024 |
| Buckingham Leasing Limited | Administrative & support | 2003 |
| Buckingham Lords Limited | Other services | 2016 |
| Buckingham Lounge Ltd | Hospitality | 2020 |
| Buckingham Nails and Spa Ltd | Other services | 2024 |
| Buckingham Nurseries Limited | Wholesale & retail | 2003 |
| Buckingham Office Supplies Limited | Wholesale & retail | 2015 |
| Buckingham Old Gaol Trust | Arts & recreation | 1985 |
| Buckingham Podiatry Limited | Health & social care | 2024 |
| Buckingham Rufc Trading Co. Ltd | Wholesale & retail | 2024 |
| Buckingham Safety Inspections Limited | Professional & scientific | 2016 |
| Buckingham Solutions Limited | Administrative & support | 2022 |
| Buckingham Technologies Ltd | Professional & scientific | 2017 |
| Buckingham Therapy Group Ltd | Other services | 2022 |
| Buckingham Turkuaz Limited | Real estate | 2023 |
| Buckingham Youth Clubs Ltd | Administrative & support | 2011 |
| Buckingham's Tea Room Ltd | Hospitality | 2023 |
| Buckinghamshire Plastering Limited | Construction | 2025 |
| Buckinghamshire Property Ltd | Real estate | 2023 |
| Buckley 2025 Ltd | Wholesale & retail | 2025 |
| Bucks Cricket Board Limited | Arts & recreation | 2010 |
| Bucks Gospel Fellowship CIC | Other services | 2024 |
| Bucks Park Services Ltd | Administrative & support | 2013 |
| Build-It-All (Buckingham) Ltd | Construction | 2019 |
| Buildwise Property Services (UK) Limited | Construction | 2021 |
| Built by Moore Ltd | Construction | 2025 |
| Bukwild Limited | Manufacturing | 2026 |
| Bulldog Pallets & Sons Ltd | Extraterritorial | 2024 |
| Bullhegge Ltd | Other services | 2019 |
| Bunsoy Trading Ltd | Wholesale & retail | 2012 |
| Burden Consultants Ltd | Other services | 2022 |
| Burgess Building Maintenance Limited | Administrative & support | 2019 |
| Burgess Windows and Doors Ltd | Construction | 2019 |
| Burley Estates Ltd | Construction | 2023 |
| Burnham Overy Property Management Ltd | Real estate | 2025 |
| Burwood Projects (UK) Ltd | Construction | 2015 |
| Buthlaw Services LLP | | 2019 |
| Buxon Properties Limited | Real estate | 2006 |
| Buzzard Holt Hosting Ltd | Hospitality | 2021 |