| Autocare & Valeting Ltd | Wholesale & retail | 2021 |
| Automech Repairs & Recovery Limited | Wholesale & retail | 2019 |
| Automotive Connectors Ltd | Wholesale & retail | 2013 |
| Automotive Fleet Investments Limited | Financial services | 2017 |
| Autos M&D Ltd | Wholesale & retail | 2022 |
| Autotech MOT Huntingdon Limited | Wholesale & retail | 2025 |
| Autrufus Limited | Information & communication | 2023 |
| AV Technologies Limited | Information & communication | 2019 |
| AV Xpert Limited | Administrative & support | 2014 |
| AVA Recruitment Ltd | Administrative & support | 2021 |
| Avanit Systems Limited | Information & communication | 2018 |
| Aventure Partners Limited | Extraterritorial | 2022 |
| Aversley Property Services Limited | Construction | 1988 |
| AVH Parks Limited | Water & waste | 2016 |
| AVH Solar Limited | Energy | 2022 |
| Aviation Training Ltd | Education | 2020 |
| Avid Hifi Limited | Manufacturing | 2005 |
| Avismo Aesthetics & Skin Ltd | Health & social care | 2025 |
| Avolly Cycling Limited | Real estate | 2019 |
| Avolux Ltd | Wholesale & retail | 2025 |
| AVR Photonics Group Limited | Financial services | 2021 |
| AWG Business Centres Limited | Construction | 2006 |
| AWG C4 Limited | Real estate | 2019 |
| AWG Corporate Services Limited | Professional & scientific | 2020 |
| AWG Group Limited | Professional & scientific | 1989 |
| AWG Land Holdings Limited | Real estate | 2002 |
| AWG Parent Co Limited | Professional & scientific | 2000 |
| AWG Property Director Limited | Extraterritorial | 2005 |
| AWT Farm Services LLP | | 2003 |
| AXE & Compass Limited | Hospitality | 2003 |
| Axis Event Solutions Ltd | Arts & recreation | 2022 |
| Aygun Properties Ltd | Real estate | 2022 |
| Ayrton Capital Limited | Construction | 2025 |
| Ayza Property Ltd | Real estate | 2018 |
| Azureus Ltd | Information & communication | 2024 |
| B & P Finishings Ltd | Construction | 2020 |
| B & R UK Ltd | Real estate | 2022 |
| B & S Retail Limited | Wholesale & retail | 2018 |
| B and Co Studio Ltd | Professional & scientific | 2025 |
| B C Horror Ltd | Information & communication | 2013 |
| B Cosmin Ltd | Transport & logistics | 2024 |
| B F Management Services Limited | Information & communication | 2010 |
| B Higgins Consulting Limited | Professional & scientific | 2021 |
| B Jordan Tech Ltd | Information & communication | 2019 |
| B W Consult Limited | Information & communication | 2015 |
| B W Rail Services Limited | Professional & scientific | 2024 |
| B&H Digital Ltd | Administrative & support | 2006 |
| B&M S4U Limited | Energy | 2018 |
| B.E.S. (Ramsey) Limited | Other services | 2004 |
| B.I Catering Equipment Services Trustees Limited | Administrative & support | 2024 |
| B.O.W. Drywall Limited | Construction | 2003 |
| B.S.W.K. Limited | Real estate | 2012 |
| BA Safety & Security Solutions Limited | Extraterritorial | 2024 |
| Baanthai Wellness and Spa Ltd | Other services | 2021 |
| Back-Ups Power Ltd | Extraterritorial | 2022 |
| Backbeat Productions Ltd | Administrative & support | 2022 |
| Backwoodsman Limited | Arts & recreation | 2005 |
| Bailes Consultants Limited | Professional & scientific | 2016 |
| Bailey & Clark Property Ltd | Households | 2025 |
| Bajco Ltd | Professional & scientific | 2021 |
| Bajoo & Co Ltd | Extraterritorial | 2020 |
| Baka Organisation Ltd | Hospitality | 2021 |
| Baked Escape Ltd | Manufacturing | 2024 |
| Balance by Lizzie Ltd | Arts & recreation | 2025 |
| Baletran Ltd | Wholesale & retail | 2018 |
| Ballinger Construction Limited | Construction | 2019 |
| Bama Holdings Ltd | Financial services | 2025 |
| Bama Homes Ltd | Real estate | 2021 |
| Bama Homes SPV1 Ltd | Real estate | 2025 |
| Bambridge LEE Holdings Limited | Real estate | 2022 |
| Bambridge LEE Limited | Professional & scientific | 2014 |
| Bance Court Management Company Limited | Households | 2021 |
| Band-It Labels Limited | Manufacturing | 1997 |
| Bar Events Ltd | Hospitality | 2026 |
| Barbiaux Limited | Professional & scientific | 2010 |
| Barcraft Ltd | Hospitality | 2023 |
| Bardernorth Limited | Real estate | 1978 |
| Barfield Work Ltd | Professional & scientific | 2024 |
| Barham Electrical Limited | Administrative & support | 2012 |
| Barracudas Holdings Limited | Financial services | 2018 |
| Barracudas Midco Limited | Administrative & support | 2018 |
| Bartlett Automotive (Huntingdon) Limited | Wholesale & retail | 2017 |
| Bartlett Automotive (Peterborough) Limited | Wholesale & retail | 2017 |
| Bartlett Automotive Holdings Limited | Financial services | 2017 |
| Bartlett Prestige Vehicles Limited | Wholesale & retail | 2023 |
| Bartons Properties Limited | Households | 2016 |
| Basenotes International Ltd | Information & communication | 2015 |
| Basket and Beyond Ltd | Wholesale & retail | 2025 |
| Basol & Partners Ltd | Professional & scientific | 2017 |
| BAT Drive Ltd | Transport & logistics | 2017 |
| Bates Manufacturing & Supply Chain Solutions Ltd | Professional & scientific | 2024 |
| Baudet Equestrian Limited | Energy | 2012 |
| BAX & Company Innovation Services Ltd | Professional & scientific | 2016 |
| BBA Investments Limited | Real estate | 2024 |
| Beacon Wealth Estates Limited | Real estate | 2018 |
| Beacon Wealth Group Limited | Professional & scientific | 2002 |
| Beacon Wealth Management Limited | Financial services | 2004 |
| Beacon Wealth Storage Limited | Administrative & support | 2016 |
| Beam Machinery Limited | Wholesale & retail | 2016 |
| Beamglow Limited | Manufacturing | 1966 |