| Avada Cloud Limited | Information & communication | 2021 |
| Avada Connect Ltd | Information & communication | 2018 |
| Avada Group Limited | Financial services | 2025 |
| Avada Services Limited | Information & communication | 2025 |
| Availability Limited | Wholesale & retail | 2022 |
| Avan Brothers Ltd | Wholesale & retail | 2017 |
| Avant (BBH) NO.2 Limited | Construction | 1946 |
| Avant Homes (Central) Limited | Extraterritorial | 1989 |
| Avant Homes (England) Limited | Construction | 1972 |
| Avant Homes (Lincoln) Limited | Construction | 1999 |
| Avant Homes (NO.2) Limited | Professional & scientific | 2009 |
| Avant Homes (Sunderland) Limited | Extraterritorial | 1998 |
| Avant Homes (Yorkshire) Limited | Construction | 2002 |
| Avant Homes Group Limited | Professional & scientific | 2014 |
| Avant Homes Group NO.2 Limited | Professional & scientific | 2009 |
| Avant Homes Holdings Limited | Professional & scientific | 2012 |
| Avant Homes Limited | Professional & scientific | 1996 |
| Avanti GAS Limited | Wholesale & retail | 1950 |
| Avantigas on Ltd | Energy | 2016 |
| AVB Mills Ltd | Manufacturing | 2009 |
| Avipro Ltd | Information & communication | 2026 |
| AVK Property (Chesterfield) Limited | Real estate | 2026 |
| AVK UK Limited | Manufacturing | 1984 |
| AVK Valves Limited | Professional & scientific | 1992 |
| AVS Family Bargains Ltd | Wholesale & retail | 2025 |
| AVS Family Bargainz Ltd | Wholesale & retail | 2025 |
| AVS Wholesale Ltd | Wholesale & retail | 2009 |
| AW Plastering Ltd | Construction | 2025 |
| AW Property Services Ltd | Real estate | 2018 |
| AWA Co. (UK) Ltd | Construction | 2021 |
| Awaya Ltd | Wholesale & retail | 2025 |
| AWM Networks Limited | Information & communication | 2016 |
| Axiontex Technologies Ltd | Information & communication | 2026 |
| AY DOT Fit Limited | Construction | 2026 |
| AY Family Ltd | Hospitality | 2025 |
| Ayaan Ltd | Wholesale & retail | 2025 |
| Aydinli Limited | Other services | 2020 |
| Ayrix Ltd | Information & communication | 2025 |
| Azande Limited | Other services | 2019 |
| Azserv.Co.Uk Limited | Manufacturing | 2009 |
| Aztec E-Commerce Oils Ltd | Wholesale & retail | 2025 |
| Aztec EOT Trustees Limited | Financial services | 2021 |
| Aztec Oils Holdings Limited | Financial services | 2021 |
| Aztec Oils Limited | Manufacturing | 1998 |
| Aztec Oils Northwest Ltd | Wholesale & retail | 2022 |
| Aztec Oils Southeast Ltd | Wholesale & retail | 2023 |
| Aztec Oils Southwest Limited | Wholesale & retail | 2019 |
| Azura Global Risks Limited | Financial services | 2024 |
| Azura RE Limited | Financial services | 2024 |
| Azura Ventures UK Limited | Financial services | 2024 |
| Azzure Creative Ltd | Administrative & support | 2017 |
| B & B Vehicle Contracts Ltd | Administrative & support | 2007 |
| B & M Equestrian Supplies Ltd | Wholesale & retail | 2021 |
| B and C Electrical and Security Limited | Construction | 2019 |
| B and S I Hill Limited | Construction | 2013 |
| B D Yates Construction Ltd | Construction | 2020 |
| B Eustace Plastering Limited | Construction | 2024 |
| B H Developments (Chesterfield) Limited | Construction | 2003 |
| B Hutton Properties Ltd | Real estate | 2025 |
| B Kelly Holdings Limited | Financial services | 2022 |
| B M Data Limited | Information & communication | 2006 |
| B R Simmons Limited | Professional & scientific | 2021 |
| B W Trading Ltd | Wholesale & retail | 2015 |
| B Y Surveys and Site Engineering Limited | Professional & scientific | 2011 |
| B Y Surveys Ltd | Professional & scientific | 2024 |
| B&T Events Ltd | Wholesale & retail | 2025 |
| B&Vc Consultancy Limited | Professional & scientific | 2021 |
| B. Hill Builder Limited | Construction | 2012 |
| B.I.E. Group Limited | Professional & scientific | 1981 |
| B.I.E. International Limited | Professional & scientific | 1934 |
| B.S. Design Services Limited | Professional & scientific | 2020 |
| B1 GAS Limited | Extraterritorial | 2012 |
| B2M Technology Limited | Manufacturing | 2014 |
| B4CHANGE Consultancy Service Limited | Professional & scientific | 2023 |
| B6 Holdings Ltd | Real estate | 2023 |
| BA Connect Ltd | Information & communication | 2024 |
| BA Real Investments Limited | Real estate | 2022 |
| Babylon Traditional Barbers Ltd | Other services | 2023 |
| Baclor Limited | Professional & scientific | 2021 |
| Baco Developments Limited | Construction | 2013 |
| Bacsc Limited | Arts & recreation | 2006 |
| BAD Company Gym Limited | Arts & recreation | 2023 |
| Bad-Point Ltd | Construction | 2026 |
| Badger and BEE Properties Limited | Real estate | 2017 |
| Baekd Ltd | Wholesale & retail | 2026 |
| Baggaley Portfolio Ltd | Professional & scientific | 2014 |
| Bagshawe Arms Limited | Hospitality | 2024 |
| Bailey J Limited | Wholesale & retail | 2026 |
| Bailiwicks Management Company Limited | Households | 2008 |
| BAK PL Ltd | Administrative & support | 2017 |
| Bake and Bean Ltd | Wholesale & retail | 2026 |
| Baker Barnett Limited | Professional & scientific | 2002 |
| Bakery at the B.H Limited | Hospitality | 2024 |
| Bakewell Retreats Limited | Hospitality | 2020 |
| Bakewell Tree Care Ltd | Agriculture & fishing | 2010 |
| Balachandran Tamil School | Education | 2018 |
| Balanced Funding Solutions Limited | Financial services | 2009 |
| Ballscrew Services Limited | Manufacturing | 2005 |
| Balmoak Consultancy Services Limited | Professional & scientific | 2026 |
| Balmoak Properties Ltd | Real estate | 2022 |