| Bias IT Limited | Information & communication | 2009 |
| Bias IT Management Consultants Limited | Professional & scientific | 2008 |
| Bicester Hand Car Wash Ltd | Other services | 2013 |
| Bicker Stores Ltd | Wholesale & retail | 2022 |
| Biconstruct Ltd | Construction | 2016 |
| Bicsc Training & Services Limited | Professional & scientific | 2012 |
| BID Modulus Ltd | Administrative & support | 2025 |
| Bidbury Mill Management Company Limited | Households | 1990 |
| Biddenham Vale Management Company Limited | Households | 2009 |
| Bidenvo Limited | Water & waste | 2013 |
| Bidexzy Anji Ltd | Education | 2025 |
| Biditrans Ltd | Transport & logistics | 2016 |
| Big 5 Butchers Ltd | Hospitality | 2026 |
| Big BAD Flag Ltd | Information & communication | 2024 |
| Big Boxexpress Ltd | Transport & logistics | 2021 |
| Big Country Limited | Hospitality | 1993 |
| Big Giraffe Events Ltd | Arts & recreation | 2025 |
| Big ICT Ltd | Information & communication | 2019 |
| Big Moon Consulting Ltd | Professional & scientific | 2024 |
| Big Noise Rehearsal Studios Limited | Other services | 2015 |
| Big Noodle Limited | Professional & scientific | 2023 |
| Big Top Buckingham Park Ltd | Health & social care | 2022 |
| Big Top Nursery - Roman Park Ltd | Health & social care | 2019 |
| Big Top Nursery Limited | Health & social care | 2012 |
| Bigachiever Advisory Ltd | Professional & scientific | 2024 |
| Bigachiever Holdings Ltd | Hospitality | 2023 |
| Bigbax Ltd | Hospitality | 2018 |
| Biggleswade 10 Renewables Limited | Professional & scientific | 2023 |
| Biggleswade Homes (Bedfordshire) Limited | Real estate | 2019 |
| Bigjohn Global Trading Ltd | Wholesale & retail | 2025 |
| Bigrise Ltd | Information & communication | 2026 |
| Bigzee Consulting Ltd | Professional & scientific | 2023 |
| Bihorenii Ltd | Manufacturing | 2025 |
| Bijoux Jewels Ltd | Wholesale & retail | 2014 |
| Bikeshuttle Limited | Transport & logistics | 2019 |
| Bilacan Limited | Hospitality | 2015 |
| Bilash Estates Ltd | Real estate | 2026 |
| Bileri Accountants Bookkeeping Ltd | Professional & scientific | 2015 |
| Bileri Accountants Ltd | Professional & scientific | 2014 |
| Billing Arbours Court Management Limited | Households | 2018 |
| Billing Boilers Ltd | Construction | 2023 |
| Billing Brook School Academy Trust | Education | 2013 |
| Billing Brothers Limited | Construction | 2016 |
| Billing Car and Van Centre Limited | Wholesale & retail | 2025 |
| Billing Finance Funding Limited | Financial services | 2025 |
| Billing Finance Group Limited | Professional & scientific | 2012 |
| Billing Finance Limited | Financial services | 1983 |
| Billing Finance Midco Limited | Financial services | 2025 |
| Billing Mini Market Ltd | Wholesale & retail | 2025 |
| Billing OFF Road Experience Limited | Arts & recreation | 2019 |
| Billing Road Property Management Limited | Real estate | 2018 |
| Billing Vehicle Movements Limited | Transport & logistics | 2025 |
| Billingham Lift Services Ltd | Construction | 2024 |
| Billings Plumbing and Heating Ltd | Construction | 2023 |
| Billingsbrook Builders Limited | Construction | 2021 |
| Billy's Fish Shop Ltd | Hospitality | 2014 |
| Bina Services Limited | Other services | 2023 |
| Bindiu Ltd | Construction | 2014 |
| Bio-Logical Carbon Ltd | Professional & scientific | 2022 |
| BIO4M Solutions Ltd | Information & communication | 2020 |
| Bioagromar Ltd | Wholesale & retail | 2022 |
| Biopen Online Coaching Ltd | Administrative & support | 2026 |
| Bios Technologies Ltd | Wholesale & retail | 2024 |
| Biosphere Herbal Ltd | Wholesale & retail | 2022 |
| Biotronix Automation Ltd | Information & communication | 2026 |
| Birch Barn Limited | Administrative & support | 2014 |
| BIRCH115 Ltd | Professional & scientific | 2025 |
| Birchenall Consultancy Ltd | Professional & scientific | 2018 |
| Birchfield Fish Bar Limited | Hospitality | 2024 |
| Birchfield Store Ltd | Wholesale & retail | 2026 |
| Birchlane Properties Limited | Households | 2020 |
| Birchley Hall Limited | Real estate | 2015 |
| Birchmead Consulting Ltd | Information & communication | 2020 |
| Birmiblack Ltd | Health & social care | 2025 |
| Birsan Services Ltd | Wholesale & retail | 2024 |
| Biryani Xpress Limited | Hospitality | 2026 |
| Bisb Automotive Limited | Wholesale & retail | 2023 |
| Biscuit Imaging Ltd | Health & social care | 2019 |
| Bisdel Global Ltd | Real estate | 2024 |
| Bishop's House (Great Bowden) Management Company Limited | Real estate | 2007 |
| Bishops Estate Management Ltd | Real estate | 2002 |
| Bison Precast Limited | Extraterritorial | 2017 |
| Bita Gifts Limited | Wholesale & retail | 2017 |
| Bits and BOB Trading Ltd | Wholesale & retail | 2018 |
| Bitsza Ltd | Hospitality | 2025 |
| Biutiful Extensions Limited | Wholesale & retail | 2023 |
| Bivbor Ltd | Construction | 2013 |
| Bivol Construction Ltd | Construction | 2016 |
| Bivol Trans Ltd | Transport & logistics | 2015 |
| Bizau Construction Ltd | Construction | 2021 |
| Bizgoals Consulting Ltd | Professional & scientific | 2023 |
| Bizjuicer Limited | Professional & scientific | 2018 |
| Bizlife Protect Ltd | Financial services | 2024 |
| Bizthinkers Limited | Administrative & support | 2010 |
| Bizwiz Solutions Limited | Information & communication | 2016 |
| Bizzy B Ltd | Health & social care | 2023 |
| Bizzy Communications Limited | Education | 2026 |
| Bizzy Roade Community Interest Company | Other services | 2020 |
| BIZZY25 Holdings Limited | Financial services | 2019 |
| BJ Building Services Ltd | Construction | 2025 |