| Barataria Estates Limited | Hospitality | 2021 |
| Barber Temple U.K. Co Limited | Wholesale & retail | 2025 |
| Barberco Limited | Other services | 2010 |
| Barclay Motorsports Ltd | Arts & recreation | 2026 |
| Barclay Plant Hire LLP | | 2015 |
| Barcoating Ltd | Construction | 2025 |
| Barker and Company Financial Services Ltd. | Financial services | 2005 |
| Barker Dental Care Limited | Health & social care | 2010 |
| Barker Tdmp Holding Limited | Health & social care | 2025 |
| Barnaby Chiari Antiquarian Books Ltd | Wholesale & retail | 2007 |
| Barnard Electrical Services Limited | Other services | 2003 |
| Barnardo's Garden Village Management Company Limited | Households | 2013 |
| Barnes Carpentry Southern Ltd | Construction | 2021 |
| Barrett Electrical Ltd | Construction | 2022 |
| Barrie Neilon Ltd | Administrative & support | 2023 |
| Bartack Limited | Construction | 2002 |
| Barter for Things Ltd. | Information & communication | 2016 |
| Barton Estates (JC) Limited | Real estate | 2025 |
| Barton Lodge Care Home Ltd | Extraterritorial | 2017 |
| Barton Stacey Limited | Construction | 2026 |
| Basecamp Scaffolding Limited | Construction | 2015 |
| Basecamp Southern Limited | Financial services | 2023 |
| Bases Direct Ltd | Wholesale & retail | 2025 |
| Basing Mews Management Company Limited | Administrative & support | 1991 |
| Basingstoke Barbers Limited | Other services | 2018 |
| Bassett House Ltd | Construction | 2022 |
| Bateleur Transport PVT Ltd | Transport & logistics | 2016 |
| Bathrooms Inspired Ltd | Construction | 2014 |
| Batsafgroup Ltd | Wholesale & retail | 2022 |
| BAU - HAI Ltd | Extraterritorial | 2003 |
| BAX Buses Ltd | Transport & logistics | 2026 |
| Bayford Plumbing and Heating Ltd | Construction | 2011 |
| Baymard Research and Services UK Limited | Professional & scientific | 2025 |
| BB Drainage & Plumbing Limited | Construction | 2018 |
| BB Logistics Southern Limited | Transport & logistics | 2024 |
| BBM Addis Care Limited | Health & social care | 2015 |
| BCJ Whites Ltd | Real estate | 2019 |
| BCM2 Interior Systems Ltd | Construction | 2022 |
| Bcrg Properties Ltd | Real estate | 2021 |
| Bcvn Limited | Professional & scientific | 2016 |
| BD Power Services Ltd | Construction | 2023 |
| BDI Security Solutions Limited | Administrative & support | 2002 |
| BDM Mechanical Services Limited | Energy | 2010 |
| BDW 256 Ltd | Administrative & support | 2025 |
| BE Amazed Media Ltd | Information & communication | 2017 |
| BE Club Ltd | Arts & recreation | 2025 |
| Beach Villas Investments Limited | Financial services | 2014 |
| Beach Villas Limited | Administrative & support | 2020 |
| Beachln Properties Ltd | Real estate | 2023 |
| Beales Technical Services Ltd | Construction | 2026 |
| Beam Group Holdings Ltd | Financial services | 2021 |
| Beam Investments Ltd | Real estate | 2020 |
| Bear & PIE Ltd | Real estate | 2023 |
| Bearface Theatre CIC | Arts & recreation | 2015 |
| Beaulieu Mortgages Limited | Financial services | 2017 |
| Beaumont Development (Totton) Limited | Real estate | 2025 |
| Beaumont Heaters Limited | Extraterritorial | 2011 |
| Beaumont Water Heaters Limited | Manufacturing | 2018 |
| Beaune Property Services Limited | Real estate | 2026 |
| Beauty Boutique Fair Oak Limited | Other services | 2022 |
| Beauty Hot Spot (Hampshire) Limited | Wholesale & retail | 2019 |
| Beauty Studio 62 Ltd | Other services | 2023 |
| Beauworth Plumbing & Heating Limited | Construction | 2005 |
| Beckworth Limited | Wholesale & retail | 2008 |
| Becky Sherry the Health Clinic Ltd | Health & social care | 2026 |
| Bedrok Limited | Professional & scientific | 2014 |
| BEE Concept Consultancy Limited | Professional & scientific | 2022 |
| BEE Loved Blooms Limited | Administrative & support | 2013 |
| Beech Vehicles & Plant Sales Limited | Wholesale & retail | 2011 |
| Beechmede Solutions Limited | Administrative & support | 2017 |
| Beechwood Property Solutions Limited | Construction | 2013 |
| Beegate Limited | Wholesale & retail | 2024 |
| Beehives Hair Studio Ltd | Other services | 2018 |
| Beeline Fencing Limited | Construction | 2015 |
| Belgrave Consulting Limited | Professional & scientific | 1998 |
| Bell & Co (Accountancy Services) Limited | Professional & scientific | 1995 |
| Bell Court (Romsey) Limited | Households | 2003 |
| Bell SC Ltd | Professional & scientific | 2012 |
| Bell Tent Glamping Limited | Hospitality | 2017 |
| Bell Tree Services Limited | Administrative & support | 2022 |
| Bella's Brigadeiros Limited | Manufacturing | 2025 |
| Belle and James Ltd | Public administration | 2022 |
| Bellissima Beauty Limited | Other services | 2018 |
| Belmont School (Feldemore) Educational Trust Limited | Education | 1965 |
| Belnua Ltd | Wholesale & retail | 2025 |
| BEN Thorpe Financial Services Limited | Professional & scientific | 2018 |
| Benfield Fire Safety Ltd | Public administration | 2015 |
| Bengal Curry Ltd | Hospitality | 2017 |
| Bennett Associates Fire Safety Consultants Ltd | Professional & scientific | 2012 |
| Benning Holdings Ltd | Real estate | 2024 |
| Berewood (Waterlooville) Management Limited | Households | 2013 |
| Berkshire Park Homes Limited | Financial services | 2006 |
| Berties TM Services Ltd | Transport & logistics | 2024 |
| Bespoke Brows and Aesthetics Ltd | Other services | 2017 |
| Bespoke Destinations Limited | Administrative & support | 2023 |
| Bespoke Engineering Creations Ltd | Professional & scientific | 2024 |
| Bespoke Load Solutions Limited | Administrative & support | 2016 |
| Bespoke Yacht Services Limited | Arts & recreation | 2006 |
| Best Batted COD Ltd | Hospitality | 2026 |
| Best Price Car Sales Ltd | Wholesale & retail | 2014 |