| Aurora Children's Foundation | Health & social care | 2015 |
| Avantica Limited | Professional & scientific | 2000 |
| Avenue Court (Management) Limited | Real estate | 1989 |
| Avenue Pizza Limited | Hospitality | 2014 |
| AWS Ventures Ltd | Professional & scientific | 2024 |
| Axiom Pipe Services Limited | Construction | 2011 |
| Axis Sports Clinic Ltd | Health & social care | 2025 |
| Axxiom Projects Ltd | Construction | 2023 |
| B Dewhirst Estates Limited | Real estate | 2025 |
| B&G (Europe) Holding Ltd | Professional & scientific | 2015 |
| B.R.A.D. Plant Hire Limited | Construction | 2008 |
| B2 Fish and Chips Ltd | Hospitality | 2012 |
| Badgerhill Properties Management Company Limited | Households | 2017 |
| Bailey Joinery Limited | Construction | 2022 |
| Bailey Waste Management Limited | Professional & scientific | 1992 |
| BAN Properties Limited | Real estate | 2024 |
| Bankruptcy Advisory Service Limited | Financial services | 2003 |
| Barnoon Ltd | Administrative & support | 2007 |
| Barnoon Properties Ltd | Real estate | 2025 |
| Barnsley Honda Ltd | Wholesale & retail | 2002 |
| Barratts Property Management Limited | Hospitality | 2025 |
| Barrowby Roofing Contractors Limited | Construction | 2021 |
| Barsebeck Advisory Ltd | Professional & scientific | 2024 |
| Bartholomew Trustee Company Ltd | Professional & scientific | 2001 |
| Bartle Mgmt Ltd | Households | 2017 |
| Barwick Roofing Limited | Construction | 2022 |
| Base 1 Architects Limited | Professional & scientific | 2005 |
| BC Accountants Limited | Professional & scientific | 2016 |
| BC Bookkeeping Services Limited | Professional & scientific | 2023 |
| BC Utility Solutions Ltd | Energy | 2024 |
| BDW Care Ltd | Health & social care | 2019 |
| BE Device Wise Limited | Education | 2025 |
| BED Guru Limited | Wholesale & retail | 2015 |
| Bedford Shelving Limited | Wholesale & retail | 2008 |
| Bedspredz Poultry Ltd | Manufacturing | 2018 |
| Bedstar Ltd | Wholesale & retail | 2004 |
| Bedsteppers Ltd | Administrative & support | 2014 |
| Beholder Vision Ltd | Information & communication | 2021 |
| Beja-Beja Limited | Real estate | 2012 |
| Believe in YOU Ltd | Education | 2018 |
| Bell Plastics Limited | Manufacturing | 1987 |
| Benoykel Solutions LLP | | 2021 |
| Bentwater Investments Ltd | Financial services | 2021 |
| Bernie Bear Limited | Information & communication | 2019 |
| Bess Holdco Limited | Financial services | 2026 |
| Best Electric Ltd | Wholesale & retail | 2014 |
| Best Investor Ltd | Information & communication | 2005 |
| Better Connect Limited | Other services | 2007 |
| Big Green Mountain Ltd | Administrative & support | 2016 |
| Big River Consulting Ltd | Professional & scientific | 2018 |
| BIO MED CBD Ltd | Wholesale & retail | 2020 |
| Biosave Limited | Extraterritorial | 2012 |
| Black Dog Hydrotherapy Ltd | Professional & scientific | 2019 |
| Black Lake (UK) Ltd | Administrative & support | 2006 |
| Blackshaw Howell Consulting Ltd | Professional & scientific | 2015 |
| Blind Jacks Ltd | Hospitality | 2018 |
| Bloom Consulting Group Ltd | Information & communication | 2025 |
| Blue Properties UK Limited | Real estate | 2002 |
| Blueberry Technical Services Ltd | Construction | 2019 |
| Bluestone Site Services Ltd | Professional & scientific | 2021 |
| BNL (UK) Limited | Manufacturing | 1991 |
| BOK Buildings Limited | Real estate | 2024 |
| Bond and Behaviour Ltd | Other services | 2025 |
| Bongkot Ltd | Other services | 2025 |
| Borngood Properties Ltd | Real estate | 2025 |
| Boston Property Building & Maintenance Ltd | Construction | 2017 |
| Boston Property Group Ltd | Construction | 2012 |
| Boujeé Luxe Ltd | Other services | 2023 |
| BPF1 Limited | Financial services | 2019 |
| Brad Construction Limited | Construction | 2019 |
| Bradstone Limited | Agriculture & fishing | 2026 |
| Bradstyle Limited | Financial services | 2003 |
| Brandenburg (UK) Limited | Manufacturing | 1998 |
| Brandenburg Holdings Limited | Financial services | 2008 |
| Branston Consultancy Limited | Professional & scientific | 2019 |
| Brasset Limited | Real estate | 2023 |
| Bridge House Investments Limited | Wholesale & retail | 2026 |
| Bridgefield (Leeds) Limited | Real estate | 2003 |
| Bridgehead 21 Limited | Professional & scientific | 2020 |
| Bright Turtle Limited | Information & communication | 2025 |
| Brisag Limited | Wholesale & retail | 2023 |
| Brock Original Limited | Other services | 2010 |
| Bromberg Consulting Limited | Financial services | 2024 |
| Brompton Leisure Ltd | Hospitality | 2025 |
| Brompton Solar Limited | Other services | 2021 |
| Browning Sykes Associates Limited | Administrative & support | 2003 |
| Bsgrp Ltd | Administrative & support | 2022 |
| Buitelaar Foods Limited | Manufacturing | 2020 |
| Buitelaar Holdings Limited | Wholesale & retail | 2019 |
| Byards Park Management Company Limited | Households | 1988 |
| Byoond Medical Ltd | Professional & scientific | 2022 |
| Byte Wave Tech Limited | Wholesale & retail | 2024 |
| C & M Stone Limited | Manufacturing | 2024 |
| C & T Matrix Limited | Manufacturing | 1994 |
| C Dobson Electrical Ltd | Construction | 2015 |
| C J Clark Forestry Limited | Manufacturing | 2026 |
| Cairnsworths Consulting Ltd | Professional & scientific | 2018 |
| Calder Valley Car Sourcing Limited | Wholesale & retail | 2026 |
| Calgas-Uk Ltd | Professional & scientific | 2026 |
| Calum Whitfield Limited | Wholesale & retail | 2024 |