| Bermuda Court (Southampton) Management Company Limited | Households | 1996 |
| Bernard Maitland (2020) Limited | Financial services | 2020 |
| Bernard Maitland Ltd | Financial services | 2015 |
| Bernard Street Limited | Real estate | 2017 |
| Bernie Spratt Limited | Construction | 2003 |
| Berry Energy Solutions Limited | Construction | 2025 |
| Berry Tree Confectionary Limited | Wholesale & retail | 2024 |
| Berry Tree Inc Limited | Wholesale & retail | 2025 |
| Berryman Consulting Limited | Professional & scientific | 2006 |
| Berrywood Business Services Limited | Professional & scientific | 2005 |
| Berrywood Farm Limited | Agriculture & fishing | 2024 |
| Berstone Limited | Professional & scientific | 2009 |
| BES (Building Environmental Services) Ltd | Professional & scientific | 2019 |
| Besmir Construction Ltd | Construction | 2023 |
| Bespoke Buttons Ltd | Arts & recreation | 2025 |
| Bespoke Carpentry Ltd | Construction | 2024 |
| Bespoke Cleans Limited | Administrative & support | 2026 |
| Bespoke Hair Designs Southampton Limited | Other services | 2013 |
| Bespoke Metal Furniture Limited | Manufacturing | 2025 |
| Bespoke Modular Developments Limited | Construction | 2015 |
| Bespoke Moments Limited | Wholesale & retail | 2022 |
| Bespoke Overland Systems Limited | Administrative & support | 2014 |
| Bespoke Safety & Training Limited | Education | 2024 |
| Bespoke Sailing Limited | Arts & recreation | 2024 |
| Bespoke Sharepoint Limited | Administrative & support | 2013 |
| Bespoke Talent Ltd | Administrative & support | 2024 |
| Best ALI Cars Ltd | Wholesale & retail | 2025 |
| Best Brains of UK Limited | Education | 2020 |
| Best Car Repair Ltd | Wholesale & retail | 2025 |
| Best Fresh Cleaning Solutions Ltd | Administrative & support | 2021 |
| Best Kebab 58 Ltd | Hospitality | 2024 |
| Best ME I CAN BE Ltd | Health & social care | 2020 |
| Best Online Limited | Wholesale & retail | 2012 |
| Best Selling Store Ltd | Wholesale & retail | 2020 |
| Best Solutions Care Ltd | Administrative & support | 2021 |
| BESTCARE24 Ltd | Health & social care | 2021 |
| Besteffect Limited | Construction | 2017 |
| Bestlife Health Investment Ltd | Wholesale & retail | 2021 |
| Beta Medica Ltd | Wholesale & retail | 2022 |
| Betapem Ltd. | Health & social care | 2015 |
| Betas Forge Ltd | Wholesale & retail | 2025 |
| Beth COX Inclusion Consultancy Ltd | Information & communication | 2024 |
| Betsy Rose Properties Limited | Real estate | 1999 |
| Betta-Cut Ltd | Wholesale & retail | 2004 |
| Better Cleaning Services Limited | Administrative & support | 2024 |
| Better Network Solutions Limited | Information & communication | 2000 |
| Better Space Solutions Ltd | Construction | 2024 |
| Betteridge Group Holdings Ltd | Financial services | 2025 |
| Betteridge Homes Limited | Construction | 2024 |
| Betting Limited | Arts & recreation | 1994 |
| Bevis Trading Limited | Construction | 2020 |
| Bexian Holdings Ltd | Financial services | 2018 |
| Bexian Marine Services Ltd | Transport & logistics | 2018 |
| Beynon Marketing and Consultancy Limited | Other services | 2026 |
| Beyond Design Consultancy Ltd | Professional & scientific | 2025 |
| Beyond Horizon Projects Ltd | Information & communication | 2024 |
| Beyond Transport Ltd | Transport & logistics | 2026 |
| Beyond YTT Ltd | Education | 2020 |
| Beyonder Boating Limited | Arts & recreation | 2021 |
| Bezel Edge Ltd | Wholesale & retail | 2025 |
| Bezenjo Ltd | Wholesale & retail | 2025 |
| BF Corporation UK Branch Ltd | Other services | 2018 |
| Bfab Group Limited | Construction | 2019 |
| Bfit Pilates Ltd | Other services | 2026 |
| BG Electrical and Plumbing Limited | Construction | 2025 |
| BG Event & Creative Services Ltd | Professional & scientific | 2025 |
| BG Locum Solutions Ltd | Health & social care | 2016 |
| Bgdk Developments Ltd | Real estate | 2024 |
| BGK Construction Limited | Construction | 2015 |
| BGM Civils Limited | Construction | 2026 |
| BHA Management Ltd | Construction | 2023 |
| Bhagat LAL Ltd | Real estate | 2022 |
| Bhakar Lets Ltd | Households | 2024 |
| Bharaksmi Ltd | Wholesale & retail | 2021 |
| Bharucha Traders Limited | Wholesale & retail | 2023 |
| Bhcn Limited | Other services | 2012 |
| BHE Developments Ltd | Construction | 2019 |
| Bhivelive Ltd | Professional & scientific | 2018 |
| Bholah Ltd | Transport & logistics | 2017 |
| Bholes UK Ltd | Wholesale & retail | 2017 |
| Bhullar and SON Limited | Construction | 2024 |
| Bhupendra Bose Real Estate Limited | Administrative & support | 2006 |
| BI Design Consulting Ltd | Professional & scientific | 2015 |
| Bi-Fold Rolfe Limited | Manufacturing | 1990 |
| Bianka"S Expert Cleaning Ltd | Administrative & support | 2025 |
| Bicuku Ltd | Real estate | 2023 |
| BID Edge Limited | Information & communication | 2024 |
| Biddenfield Estate Management Limited | Agriculture & fishing | 2014 |
| Biddz Boxing Limited | Arts & recreation | 2019 |
| Biedronka Foods Ltd | Wholesale & retail | 2025 |
| Big AXE Throwing Ltd | Arts & recreation | 2022 |
| Big Bangz UK Ltd | Arts & recreation | 2024 |
| Big BEN Marketing & Communications Ltd | Professional & scientific | 2024 |
| Big Cat Boat Charters Ltd | Transport & logistics | 2024 |
| Big Data Business Intelligence Ltd | Information & communication | 2021 |
| Big Dog Nutrition Ltd | Wholesale & retail | 2026 |
| Big FAT Stacks Limited | Professional & scientific | 2022 |
| Big House Properties Ltd | Real estate | 2016 |
| Big MAC Shipping Ltd | Transport & logistics | 2025 |
| Big Mallet Limited | Professional & scientific | 2012 |