| BHE Capella Ltd | Real estate | 2021 |
| BHE Deneb Ltd | Real estate | 2021 |
| BHE Electra Ltd | Real estate | 2026 |
| BHS Aviation Ltd | Manufacturing | 2025 |
| Bhubesi Pride Foundation | Education | 2013 |
| BI-ZSA1992 Ltd | Manufacturing | 2025 |
| BIA DAO Ltd | Professional & scientific | 2021 |
| BIA GP Ltd | Manufacturing | 2021 |
| Biai Company Ltd | Manufacturing | 2024 |
| Bianca & Andrei Ltd | Transport & logistics | 2016 |
| Bibble Bobble Productions Ltd | Arts & recreation | 2021 |
| Bibetta Limited | Wholesale & retail | 2004 |
| Bickenhall Freehold Limited | Real estate | 1994 |
| Bickenhall Mansions Management Limited | Households | 1972 |
| Bickenhall Properties Limited | Real estate | 2003 |
| Bicon Continuity Limited | Education | 2011 |
| Bicycle Therapeutics PLC | Administrative & support | 2017 |
| Bicyclerd Limited | Administrative & support | 2009 |
| Bicycletx Limited | Administrative & support | 2017 |
| Biddys Auction Limited | Wholesale & retail | 2019 |
| Bidwells Investment Management LLP | | 2024 |
| Bidwells LLP | | 2009 |
| Big Brute Industries Limited | Professional & scientific | 2002 |
| Big Buddha Developments Ltd | Construction | 2017 |
| Big Chef's Burger Ltd | Hospitality | 2024 |
| Big D'S Musical Estate Limited | Information & communication | 2025 |
| Big Dipper Technology Ltd | Professional & scientific | 2019 |
| Big Dog Medical Media Ltd | Information & communication | 2020 |
| Big Fish Enterprises Ltd. | Arts & recreation | 2008 |
| Big Peat Sheet Metal Services Ltd | Manufacturing | 2025 |
| Big Picture Health Protection Ltd | Health & social care | 2023 |
| Bigbang Properties Ltd | Real estate | 2023 |
| Bigdhub Limited | Information & communication | 2023 |
| Biggsvision Ltd | Wholesale & retail | 2024 |
| Bigmother.Ai CIC | Other services | 2018 |
| Bijulescu&Co Ltd | Manufacturing | 2025 |
| Bikesurfer Ltd | Administrative & support | 2025 |
| Bildeston Road (Combs) Management Company Limited | Households | 2024 |
| Bill BE Waffle Limited | Hospitality | 2023 |
| Binary Silk Ltd | Information & communication | 2017 |
| Bingbel Ltd | Information & communication | 2016 |
| Bingley & Parker Properties Limited | Real estate | 2021 |
| Binmar Ltd | Manufacturing | 2025 |
| Binshabbir Ltd | Wholesale & retail | 2025 |
| Bio-Cfo Ltd | Professional & scientific | 2013 |
| Bioanalytica Ltd | Professional & scientific | 2023 |
| Biobridge Limited | Professional & scientific | 1988 |
| Biobullets Holdings Limited | Professional & scientific | 2014 |
| Biobullets Limited | Professional & scientific | 2000 |
| Biocair International Limited | Transport & logistics | 1986 |
| Biochrom Limited | Manufacturing | 1998 |
| Biodata Clarity Limited | Professional & scientific | 2023 |
| Biodenta Limited | Wholesale & retail | 2022 |
| Biodiversity Without Borders Ltd | Professional & scientific | 2025 |
| Biodrop Ltd | Manufacturing | 2012 |
| Bioele Limited | Professional & scientific | 2025 |
| Bioethical Limited | Professional & scientific | 2024 |
| Biofab Innovations Ltd | Professional & scientific | 2025 |
| Biofidelity Ltd | Professional & scientific | 2019 |
| Bioflares Ltd | Wholesale & retail | 2021 |
| Bioform Strategic Communications Limited | Professional & scientific | 2026 |
| Biogeek Ltd | Professional & scientific | 2026 |
| Bioinception PVT Ltd | Professional & scientific | 2018 |
| Bioinformate Ltd | Professional & scientific | 2022 |
| Biolatris Limited | Administrative & support | 2007 |
| Bioleap Ltd | Information & communication | 2022 |
| Bioleap Trustee Limited | Financial services | 2022 |
| Biologics R&D Ltd | Professional & scientific | 2023 |
| Biomet.Life Ltd | Information & communication | 2025 |
| Biomind Consultants Ltd | Professional & scientific | 2025 |
| Biopack Trading Co., Ltd | Wholesale & retail | 2025 |
| Biopharmalogic Limited | Professional & scientific | 1996 |
| Bioplastuk Ltd | Manufacturing | 2025 |
| Biorbyt Ltd | Wholesale & retail | 2010 |
| Bios Health Ltd | Professional & scientific | 2015 |
| Biosceptre (UK) Limited | Professional & scientific | 2013 |
| Biosceptre International Limited | Professional & scientific | 2013 |
| Biosomicx Solutions Ltd | Professional & scientific | 2025 |
| Biostatistics Consulting Ltd | Information & communication | 2019 |
| Biosynergy (Europe) Limited | Professional & scientific | 1991 |
| Biosynergy Holdings Limited | Financial services | 2020 |
| Biotech Agro Food Life Consulting Ltd | Professional & scientific | 2025 |
| Biotech Procurement Solutions Limited | Professional & scientific | 2024 |
| Biotelic Consulting Ltd | Professional & scientific | 2020 |
| Biotryp Therapeutics Ltd | Professional & scientific | 2023 |
| Biotsphere Limited | Wholesale & retail | 2009 |
| Biovita Nutra Limited | Wholesale & retail | 2026 |
| Biozeroc Ltd | Professional & scientific | 2021 |
| BIQ Associates Limited | Health & social care | 1998 |
| BIR Research Ltd | Professional & scientific | 2019 |
| Birch Close Residents Association Limited(The) | Real estate | 1967 |
| Birch's Farms Limited | Agriculture & fishing | 2024 |
| Birch's Groundworks Limited | Construction | 2025 |
| Birch's Holdings Ltd | Financial services | 2025 |
| Birch's Parks Limited | Hospitality | 1997 |
| Birchcroft Management Company Ltd | Households | 2019 |
| Bird & Morgan Ltd | Transport & logistics | 2020 |
| Bird & Yates Motor Services Limited | Wholesale & retail | 2020 |
| Bird Box Gallery CIC | Health & social care | 2024 |
| Birdie&Co Ltd | Wholesale & retail | 2014 |