| Bagan Central Limited | Information & communication | 2018 |
| Bailey Home Improvements Ltd | Professional & scientific | 2026 |
| Bailie Cross Garage Limited | Wholesale & retail | 2004 |
| Bainton Flooring Limited | Wholesale & retail | 2006 |
| Bakado Solutions Ltd | Information & communication | 2019 |
| Baker IT Solutions Limited | Information & communication | 2011 |
| Baker Materials Handling Consulting Limited | Information & communication | 2021 |
| Bakers View Residents Association Limited | Households | 2010 |
| Bakewise Limited | Wholesale & retail | 2015 |
| Balance Solutions Limited | Professional & scientific | 2018 |
| Balay Limited | Real estate | 2025 |
| Balcombe Consulting Limited | Professional & scientific | 2016 |
| Ballard Design Limited | Professional & scientific | 2024 |
| Balmerengineering Limited | Construction | 2026 |
| Balson Homes Limited | Construction | 2012 |
| Balson Properties Limited | Real estate | 2023 |
| Banba Limited | Information & communication | 2016 |
| Banbury QMS Limited | Professional & scientific | 2024 |
| Bandsman Limited | Professional & scientific | 2019 |
| Banyan Moon Properties Limited | Real estate | 2019 |
| Bar Bar Black Sheep Ltd | Hospitality | 2026 |
| Bar DES Amis Limited | Professional & scientific | 2022 |
| Bar Library Wines & Spirits Merchants Limited | Wholesale & retail | 2020 |
| Bare Copse Batteries Ltd | Construction | 2024 |
| Bare Necessities Boiler Care Limited | Construction | 2018 |
| Barilla Kennels Limited | Other services | 1956 |
| Barilla Limited | Wholesale & retail | 2007 |
| Barnett Consultancy Limited | Information & communication | 2018 |
| Barns Furr Ltd | Professional & scientific | 2019 |
| Barnwell Property Group Limited | Construction | 2024 |
| Barnwood Storage Ltd | Transport & logistics | 2021 |
| Barook Developments Limited | Construction | 2018 |
| Barrack Quarter (Dorchester) Ltd | Real estate | 2025 |
| Barry J Mills Limited | Professional & scientific | 2003 |
| Barsims Leisure Limited | Hospitality | 2017 |
| Barton Projects Limited | Construction | 2014 |
| Barton Real Estate Holdings Limited | Financial services | 2026 |
| Barvi Limited | Information & communication | 2016 |
| Basam Investments Limited | Real estate | 2021 |
| Bascombe Contractors Limited | Extraterritorial | 2009 |
| Bascombe Holdings Limited | Financial services | 2022 |
| Basedene Limited | Households | 1992 |
| Baseline Civil Tech Limited | Professional & scientific | 2026 |
| Baseline Security Services Ltd | Administrative & support | 2022 |
| Basement Hire Ltd | Arts & recreation | 2018 |
| Basement Studio Ltd. | Information & communication | 2011 |
| BAT Digital Ltd | Administrative & support | 2014 |
| Bates MEC Limited | Professional & scientific | 2021 |
| Batricar Mobility Centre Limited | Manufacturing | 2003 |
| Battersea Consulting Limited | Information & communication | 2019 |
| Battlebuilder Ltd | Wholesale & retail | 2023 |
| Bayside Glazing and Home Improvements Limited | Construction | 2024 |
| BB Data Services Limited | Information & communication | 2025 |
| BB Fire Doors Ltd | Construction | 2020 |
| BBH Projects Ltd | Information & communication | 2022 |
| Bbone Consulting Ltd | Information & communication | 2017 |
| BBS Consultants Limited | Professional & scientific | 2003 |
| BC Development and Training Ltd | Information & communication | 2020 |
| BCR Developments Ltd | Real estate | 2014 |
| BD Building and Landscapes Ltd | Construction | 2023 |
| BD Engineering Dorset Ltd | Professional & scientific | 2022 |
| BDM Production Ltd | Information & communication | 2023 |
| BDO Engineering Services Limited | Professional & scientific | 2022 |
| BE Soccer Academy Limited | Other services | 2004 |
| Beach Inns Limited | Hospitality | 2022 |
| Beacon Hill Brick Company Limited(The) | Water & waste | 1937 |
| Beacon Hill Farm Ltd | Financial services | 2020 |
| Beam Systems Ltd | Manufacturing | 2020 |
| Bear Dashwood Ltd | Construction | 2018 |
| Bear Shamu Limited | Professional & scientific | 2015 |
| Beardow Holdings Limited | Extraterritorial | 2022 |
| Beardow Property Investments Ltd | Real estate | 2021 |
| Beaucroft Beverages Ltd | Manufacturing | 2018 |
| Beaver Plastering Ltd | Construction | 2026 |
| Beaver Westminster Limited | Professional & scientific | 2004 |
| Beavin Engineering Limited | Manufacturing | 2004 |
| Becki Sewell Ltd | Professional & scientific | 2025 |
| Beckley Plant Hire Ltd | Construction | 2003 |
| Bedrooms Bathrooms & Kitchens Limited | Construction | 2006 |
| Bedwell Consultancy Ltd | Information & communication | 2022 |
| BEE Frampton Limited | Wholesale & retail | 2003 |
| Beech CRT Maintenance Ltd | Real estate | 2024 |
| Beep Digital Ltd | Information & communication | 2015 |
| Begin-End Holding Ltd | Financial services | 2024 |
| BEH Services Limited | Information & communication | 2022 |
| Behavioural Economy Ltd | Professional & scientific | 2019 |
| Behind the Scenes Technical Services Ltd | Arts & recreation | 2015 |
| Belgard Group Ltd | Arts & recreation | 2025 |
| Belic Ltd | Information & communication | 2023 |
| Bellem Limited | Professional & scientific | 2022 |
| Bells House Freehold Limited | Real estate | 2014 |
| Bells House Woodland Limited | Administrative & support | 2017 |
| Belton Executive Coaching & Consulting Ltd | Education | 2017 |
| BEN Clarke Geohazards Consulting Ltd | Professional & scientific | 2025 |
| BEN Cook Racing Limited | Arts & recreation | 2025 |
| BEN Harrison Automotive Ltd | Wholesale & retail | 2020 |
| BEN Johnson (Shaftesbury) Ltd | Administrative & support | 2003 |
| BEN Warburton Media Limited | Professional & scientific | 2024 |
| Bence H & Co Limited | Administrative & support | 2010 |
| Bench Healthcare Management Limited | Professional & scientific | 2020 |