| Avon House Business Centre Ltd | Real estate | 2023 |
| Avon Leisure Limited | Manufacturing | 1993 |
| Avon Medical Ltd | Professional & scientific | 2025 |
| Avonside Limited | Households | 1980 |
| Avonvale Garage Doors & Glazing Ltd | Construction | 2010 |
| Avonview Design & Build Limited | Construction | 2014 |
| Avram Financial Services Limited | Financial services | 2015 |
| Avram Holdings Ltd | Financial services | 2026 |
| Avsa Tech Consulting Limited | Information & communication | 2021 |
| AW Antiques Ltd | Wholesale & retail | 2026 |
| AW GRP Limited | Financial services | 2018 |
| AW Hot Tubs Ltd | Administrative & support | 2024 |
| Awan Accountants Limited | Professional & scientific | 2012 |
| Awas Consulting Limited | Professional & scientific | 2002 |
| Awaz Glam Ltd | Wholesale & retail | 2024 |
| AWD Forestry and Tree Surgery Limited | Agriculture & fishing | 2025 |
| AWE Construction and Consulting Ltd | Construction | 2020 |
| AWE Tech Holdings Limited | Professional & scientific | 2024 |
| AWE Technologies Ltd | Information & communication | 2022 |
| AWS Healthcare Limited | Health & social care | 2026 |
| AX Holdings Limited | Information & communication | 2022 |
| Axelrod Capital Limited | Real estate | 2016 |
| AXH Consultants Ltd | Information & communication | 2012 |
| Axmg-Ct Holding Limited | Wholesale & retail | 2025 |
| AXS Trade Finance Limited | Professional & scientific | 2009 |
| Axsw Group Ltd | Information & communication | 2026 |
| Ayaan Bazar Limited | Wholesale & retail | 2025 |
| Ayce Limited | Real estate | 2025 |
| Ayda M Construction Ltd | Construction | 2022 |
| Aylesbury Developments Ltd | Construction | 2022 |
| Aylesbury Road (Wendover) Limited | Construction | 2023 |
| Ayme Projects Limited | Construction | 2023 |
| Ayyan Courier Limited | Transport & logistics | 2021 |
| AZ HU Sports Group Limited | Arts & recreation | 2025 |
| Azalea Group Limited | Professional & scientific | 2022 |
| Azalea Ventures Limited | Real estate | 2013 |
| Azalea Wealth Group Limited | Financial services | 2019 |
| Azam Properties Limited | Administrative & support | 2014 |
| Azerothian Circle Group Limited | Real estate | 2025 |
| Azionink Forensics Ltd | Administrative & support | 2024 |
| Azita Hair & Beauty Academy Ltd | Other services | 2020 |
| Aziz Property Group Limited | Real estate | 2025 |
| Aziz Property Holdings Limited | Hospitality | 2022 |
| Aziz UK Construction Limited | Construction | 2021 |
| AZR Motor Sport Ltd | Manufacturing | 2020 |
| Azraam Limited | Financial services | 2024 |
| AZS Trading Ltd | Financial services | 2026 |
| Aztec Design Limited | Construction | 2008 |
| Azurey Ltd | Real estate | 2022 |
| B & C Care Holdings Ltd | Financial services | 2025 |
| B & C Care Homes Ltd | Health & social care | 2025 |
| B & F (UK) Limited | | 1994 |
| B & L Fencing (America) Limited | Construction | 2015 |
| B & L Fencing Corporate Trustees Limited | Professional & scientific | 2023 |
| B & L Fencing Services Limited | Construction | 1992 |
| B & N Pro Logistics Ltd | Transport & logistics | 2025 |
| B & S Future Ltd | Financial services | 2024 |
| B B Utility Solutions Limited | Construction | 2022 |
| B D Rigging Ltd | Construction | 2014 |
| B K Farrelly Ltd | Construction | 2017 |
| B K Global Consulting Ltd | Information & communication | 2017 |
| B M Live Events Limited | Administrative & support | 2010 |
| B Narayan Limited | Health & social care | 2010 |
| B Optometry Ltd | Health & social care | 2024 |
| B&R Property Group Ltd | Households | 2025 |
| B.D.I. (Midlands) Limited | Construction | 2019 |
| B.N. Engineering Limited | Manufacturing | 2003 |
| B.S. Executive Travel Limited | Administrative & support | 1948 |
| B.S.B. Sheet Metal Services Limited | Manufacturing | 2008 |
| B13 Productions Ltd | Administrative & support | 2017 |
| B2 Partners Ltd | Real estate | 2018 |
| B2B Automate.Ai Limited | Information & communication | 2025 |
| B5 Central Residents Management Company Limited | Households | 2019 |
| B93 Limited | Administrative & support | 2019 |
| B94 Ltd | Hospitality | 2017 |
| BA Mobile Fleet Services Limited | Manufacturing | 2012 |
| BA Training and Talent Limited | Administrative & support | 2022 |
| Baashe Limited | Transport & logistics | 2019 |
| Baba JEE Holdings Ltd | Financial services | 2020 |
| Baba JEE Limited | Agriculture & fishing | 1998 |
| Baba JEE Poultry Limited | Extraterritorial | 2009 |
| Baby Sleep the Night Limited | Education | 2018 |
| Baby Swim Limited | Education | 2022 |
| Back Nine Social Limited | Professional & scientific | 2022 |
| Back to Happy Limited | Health & social care | 2015 |
| Back to Health Spinecare Limited | Health & social care | 2013 |
| Back-Up Services Ltd | Information & communication | 1995 |
| BAD Rabbits ALE House Limited | Hospitality | 2014 |
| Badger Industries Limited | Professional & scientific | 2025 |
| Badminton Centre LLP | | 2025 |
| Badsey Butchers Limited | Wholesale & retail | 2021 |
| Baed Property Services Ltd | Real estate | 2022 |
| Baink Ltd | Information & communication | 2025 |
| Baker Finance Ltd | Construction | 2014 |
| Baker Lettings and Property Management Ltd. | Real estate | 2009 |
| Baker Residential Properties Limited | Real estate | 2021 |
| Bakers Mews Limited | Households | 1992 |
| Baking Studio Ltd | Education | 2020 |
| Balas Investments Limited | Professional & scientific | 2019 |
| Bald Capital Ltd | Real estate | 2020 |