| Baker (City) LLP | | 2009 |
| BALES4EVENTS Limited | Administrative & support | 2018 |
| Ballet HOO Dancewear Ltd | Wholesale & retail | 2019 |
| Ballista Digital Limited | Extraterritorial | 2013 |
| Ballista Media Ltd | Information & communication | 2006 |
| Balloon BOY John Limited | Arts & recreation | 2020 |
| Bamboo Bakery Limited | Hospitality | 2010 |
| Banbrella Solutions Limited | Administrative & support | 2026 |
| Band Pass Limited | Manufacturing | 2004 |
| Bannister Property Ltd | Real estate | 2024 |
| Barn Court Residents' Association Limited | Households | 1966 |
| Barnett Creative Ltd | Professional & scientific | 2025 |
| Barnwood Carpentry Ltd | Manufacturing | 2024 |
| Baron Crafts Limited | Wholesale & retail | 2020 |
| Basic Electronics Limited | Information & communication | 1975 |
| Basylion Technologies Ltd | Information & communication | 2025 |
| Bauhinia Group Limited | Wholesale & retail | 2022 |
| Bayfics Consulting Limited | Professional & scientific | 2025 |
| Baythorn Limited | Real estate | 1962 |
| BB Production Services Ltd | Professional & scientific | 2016 |
| BB Property Ltd | Real estate | 2026 |
| BCO Property Ltd | Real estate | 2025 |
| Beaconsfield House Residents Association Limited | Households | 1992 |
| Beagles Limited | Professional & scientific | 2003 |
| Bear Interior Designs Ltd | Construction | 2023 |
| Beaucroft Limited | Information & communication | 2001 |
| Beaufield Homes Limited | Construction | 1989 |
| Beaumont (Petersfield) Ltd | Real estate | 2019 |
| Beaumont Mews (Road) Management Ltd | Real estate | 2018 |
| Beautiful Gardens Beautifully Maintained Limited | Administrative & support | 2011 |
| Beavers Rugby Ltd | Arts & recreation | 2022 |
| Becdan Limited | Wholesale & retail | 2021 |
| Beckett's Catering Limited | Hospitality | 2013 |
| Bedrock Estates Limited | Real estate | 2015 |
| BEE Renovations Ltd | Construction | 2026 |
| Beechmore Mews Management Limited | Households | 2011 |
| Beechwood Building Contractors Ltd | Construction | 2009 |
| Beer Counter Limited | Manufacturing | 2002 |
| Belivia Limited | Hospitality | 2017 |
| Bell House Nursery Limited | Administrative & support | 2009 |
| Belle Medical Limited | Professional & scientific | 2025 |
| BEN Reed Architects Limited | Professional & scientific | 2014 |
| Benbows Fish Company Ltd | Hospitality | 2021 |
| Benbows Property Investments Limited | Real estate | 2023 |
| Bench Events Limited | Administrative & support | 2008 |
| Benkled Limited | Information & communication | 2024 |
| Benson Lane Care Collaborative Limited | Health & social care | 2025 |
| Benton Evans Ltd | Professional & scientific | 2011 |
| Best of BVI Limited | Administrative & support | 2004 |
| Best Skates Ltd | Wholesale & retail | 2021 |
| Better & Partners Communications Limited | Wholesale & retail | 2018 |
| Beyond Driven Ltd | Information & communication | 2010 |
| BG School UK Ltd | Education | 2010 |
| Bibunker Ltd | Financial services | 2017 |
| Bickers Consulting Limited | Professional & scientific | 2022 |
| Bickton Estate FLY Fishing Club Limited | Agriculture & fishing | 2015 |
| Bidyas Ltd | Professional & scientific | 2024 |
| Big BOY Catering Ltd | Hospitality | 2023 |
| Big BOY Holding's Limited | Financial services | 2025 |
| Big Screen Music Production Limited | Information & communication | 2008 |
| Bigsmall Digital Limited | Information & communication | 2026 |
| BIL & SIL Limited | Wholesale & retail | 2016 |
| Bioactive Health Ltd | Manufacturing | 2018 |
| Birdswood Ecology Ltd | Professional & scientific | 2023 |
| Birdwhistle Books Ltd | Extraterritorial | 2021 |
| Bishopscare Limited | Real estate | 2014 |
| BIT Warmer Limited | Information & communication | 2017 |
| Bizflex Limited | Extraterritorial | 2012 |
| Black Box BBQ Ltd | Wholesale & retail | 2020 |
| Black Site Media Ltd | Information & communication | 2019 |
| Blackglass Ltd | Information & communication | 2013 |
| Blacklands Livery Stables Ltd | Agriculture & fishing | 1997 |
| Blackshore Property Limited | Construction | 2012 |
| Blake & Temple Limited | Agriculture & fishing | 2024 |
| Blake Thomas & Co LLP | | 2009 |
| Blank Drinks Ltd | Wholesale & retail | 2026 |
| Blap Construction & Renovation Limited | Construction | 2015 |
| Blason Dissan Limited | Professional & scientific | 2016 |
| BLE Music Limited | Information & communication | 2013 |
| Bliss HHW Ltd | Real estate | 2023 |
| Bloombox Coaching Ltd | Professional & scientific | 2025 |
| Blue Bracken Limited | Professional & scientific | 2011 |
| Blue Motion Vision Ltd | Professional & scientific | 2023 |
| Blue Mouse Services Limited | Administrative & support | 2022 |
| Bluebird Assets Ltd | Financial services | 2017 |
| Bluedot Display Limited | Manufacturing | 2000 |
| Blueide Holdings Limited | Financial services | 2026 |
| Blueshell Consultancy & Management Services Limited | Information & communication | 2017 |
| BNC Collectibles Ltd | Wholesale & retail | 2025 |
| BND Consultants Limited | Real estate | 2017 |
| Bny&Lou Ltd | Information & communication | 2025 |
| Bobsyachts UK Limited | Administrative & support | 2015 |
| Bogdan Technical Solution Ltd | Extraterritorial | 2017 |
| BOLKAN22 Ltd | Transport & logistics | 2022 |
| Bonus Salus Ltd | Wholesale & retail | 2019 |
| Boomerang Time Ltd | Information & communication | 2023 |
| Boost Music Publishing Limited | Information & communication | 2007 |
| Boosttv Limited | Information & communication | 2019 |
| Borehole Service Utilities Ltd | Construction | 2019 |
| Bosman Wines UK Ltd | Wholesale & retail | 2016 |