| Bestobell Marine Ltd | Manufacturing | 2026 |
| Better Locks T/A Lock Rite Andover Limited | Manufacturing | 2022 |
| Beverston Mews Management Company Limited | Households | 1996 |
| Beyond the Storm CIC | Health & social care | 2026 |
| Beyourfood Ltd | Hospitality | 2019 |
| Bfest Limited | Administrative & support | 2016 |
| BGH Service Ltd | Construction | 2009 |
| BH Investment (Hampshire) Ltd | Real estate | 2025 |
| BID and Capture Contracting Ltd | Professional & scientific | 2022 |
| Big Hearts Recruitment Ltd | Health & social care | 2018 |
| Big TV (Displays) Ltd | Professional & scientific | 2023 |
| Bigbash Music Label Ltd | Information & communication | 2026 |
| Bigblueenergy Ltd | Wholesale & retail | 2023 |
| Biker Van Ltd | Administrative & support | 2022 |
| BIM House Services Limited | Administrative & support | 2018 |
| Birdsong Management Services Limited | Professional & scientific | 2023 |
| Bishta Limited | Other services | 2007 |
| BLACKDOGS2 Limited | Information & communication | 2006 |
| Blacksmiths (ST. Mary Bourne) Limited | Real estate | 2010 |
| Blair & Moon Investments Limited | Financial services | 2025 |
| Blieve Holdings Ltd | Professional & scientific | 2018 |
| Blieve Ltd | Professional & scientific | 2021 |
| Blinds and Signs Limited | Wholesale & retail | 2017 |
| Blizzard Partners Limited | Professional & scientific | 2014 |
| Blockdeed Ltd | Information & communication | 2012 |
| Bloom Again Goods Ltd | Administrative & support | 2025 |
| Bloom Innovation Ltd | Construction | 2014 |
| Blooming Kids Ltd | Education | 2016 |
| Bloomsprint Limited | Manufacturing | 2021 |
| Blue 14 Consulting Services Ltd | Professional & scientific | 2026 |
| Blue Gorilla Pictures Ltd | Information & communication | 2017 |
| Blue Verge Consultancy Limited | Administrative & support | 2020 |
| Bluebell Property Management Ltd | Real estate | 2023 |
| Bluestone Homes Group Ltd | Construction | 2021 |
| Blundell Construction Limited | Construction | 2001 |
| Blunt Pubs Limited | Other services | 2017 |
| Blunt Trading Limited | Hospitality | 2017 |
| Blusky Property Investments Limited | Extraterritorial | 2021 |
| BMK Solutions Ltd | Other services | 2016 |
| Bmkcharles Ltd | Extraterritorial | 2024 |
| BND Industrial Group Limited | Manufacturing | 2019 |
| Body Activation Ltd | Professional & scientific | 2020 |
| Bodyline Auto Hub Limited | Wholesale & retail | 2025 |
| Bogdaniuk Transport Ltd | Transport & logistics | 2016 |
| Boise Cascade Office Products (UK) Limited | Extraterritorial | 1997 |
| Boldline Services Limited | | 1987 |
| Bolmen Ltd | Transport & logistics | 2014 |
| Bonneval Ltd | Professional & scientific | 2022 |
| Bonolo Enterprise Limited | Wholesale & retail | 2025 |
| Bontea Limited | Transport & logistics | 2018 |
| Book on Line Limited | Administrative & support | 2011 |
| Bookd Finance Ltd | Professional & scientific | 2026 |
| Boomboom Sound Limited | Information & communication | 2012 |
| Boros Class 2 Ltd | Transport & logistics | 2023 |
| Bosco Xavier Ltd | Professional & scientific | 2016 |
| Botgamers Ltd | Wholesale & retail | 2024 |
| Bottle & Glass Developments Ltd | Construction | 2024 |
| Bourne Accounting Ltd | Professional & scientific | 2020 |
| Bourne Valley Associates Limited | Professional & scientific | 2010 |
| Bourne Valley Contract Farming Limited | Agriculture & fishing | 2008 |
| Bourne Valley Holdings Limited | Financial services | 2014 |
| Bourne Valley Investments Ltd | Financial services | 2026 |
| Bourne Valley Systems Ltd | Information & communication | 2007 |
| Bourne Valley Trophies LLP | | 2016 |
| Bournes Estate Agents Limited | Real estate | 2006 |
| BOW and Locket Ltd | Manufacturing | 2010 |
| Bowmaker Consulting Ltd | Professional & scientific | 2024 |
| Boyriven Limited | Wholesale & retail | 1931 |
| BP Rolls (Maxus) Limited | Wholesale & retail | 2021 |
| BP Rolls (Newport) Limited | Wholesale & retail | 2001 |
| BP Rolls (North West) Limited | Wholesale & retail | 2022 |
| BP Rolls Automotive Limited | Wholesale & retail | 2016 |
| BP Rolls Group Limited | Financial services | 2001 |
| BP Rolls Signs & Graphics Limited | Manufacturing | 1999 |
| BPP Inventory Ltd | Administrative & support | 2014 |
| Bracken Place Day Nursery Limited | Education | 2004 |
| Brad Craney Brickwork & Construction Ltd | Construction | 2018 |
| Bradbury Motorworks Limited | Wholesale & retail | 2026 |
| Bradders Bits Limited | Manufacturing | 2025 |
| Bradec (Andover) Limited | Construction | 1974 |
| Bradec Construction Ltd. | Construction | 1994 |
| Bradec Group Limited | Financial services | 2018 |
| Bradec Limited | Construction | 2016 |
| Brainsteam Ltd | Information & communication | 2014 |
| Bramley Retail Ltd | Wholesale & retail | 2019 |
| Branston-Jones Ltd | Other services | 2015 |
| Braust House Management Company Limited | Households | 1987 |
| Braver Estates Limited | Construction | 2020 |
| Brawn Motorsport Engineering Ltd | Professional & scientific | 2023 |
| BRC Accountants PKL Limited | Professional & scientific | 2018 |
| Breach Farm Woodland Burial Ground Limited | Other services | 2004 |
| Bread & Butter Catering & Events. Limited | Hospitality | 2016 |
| Brennan Fabrications Ltd | Manufacturing | 2021 |
| Brevin Beeson Limited | Professional & scientific | 2006 |
| BRF Technology Limited | Administrative & support | 2007 |
| Bridal PAR Helene Limited | Wholesale & retail | 2015 |
| Bridge Cottage Bees Ltd | Agriculture & fishing | 2020 |
| Bridge Street Property Andover Ltd | Hospitality | 2024 |
| Bright Nutrition Ltd | Professional & scientific | 2018 |
| Brikt CIC | Other services | 2026 |