| Avelia Management Limited | Professional & scientific | 2018 |
| Avenzar Supplies Ltd | Wholesale & retail | 2026 |
| Avhaa Ltd | Wholesale & retail | 2022 |
| AVI GH Development Ltd | Construction | 2022 |
| Avicenna Education Ltd | Education | 2021 |
| Avik Property Ltd | Real estate | 2021 |
| Avinya Trade Limited | Wholesale & retail | 2025 |
| Avinya Visuals Ltd | Information & communication | 2025 |
| AVK Automotive Limited | Wholesale & retail | 2021 |
| AVM Power Limited | Construction | 2026 |
| AVM83 Construction Ltd | Construction | 2024 |
| Avosa Limited | Professional & scientific | 2009 |
| Avsons Ltd | Real estate | 2014 |
| Away With Words Hypnotherapy Ltd | Education | 2019 |
| Awndycorp Ltd | Information & communication | 2025 |
| AWP Legal Ltd | Professional & scientific | 2025 |
| AX Advantix London Ltd | Professional & scientific | 2013 |
| AX Advantix Services Ltd | Financial services | 2022 |
| AX Advantix Web Ltd | Information & communication | 2021 |
| AX Rating Agency Ltd | Professional & scientific | 2020 |
| AX Tax Planning Visions Ltd | Professional & scientific | 2020 |
| AX1 Film Holdings Limited | Professional & scientific | 2016 |
| Axion Properties Ltd | Real estate | 2020 |
| Ayaan Capitals Limited | Real estate | 2022 |
| AYC18 Ltd | Administrative & support | 2026 |
| Aylmer Capital Partners Limited | Financial services | 2018 |
| AYS Holdings Ltd | Financial services | 2024 |
| AYU Trading Ltd | Wholesale & retail | 2020 |
| Azabu International Ltd | Professional & scientific | 2020 |
| Azimuth Investments LLP | | 2018 |
| Azimuth Peak Advisory Ltd | Professional & scientific | 2025 |
| B & a Properties (London) Limited | Real estate | 2020 |
| B & C Security Services LLP | | 2006 |
| B & K Investments Limited | Real estate | 1997 |
| B a Finance Limited | Financial services | 2009 |
| B a Property Investment and Management Ltd | Real estate | 2017 |
| B Berisha Ltd | Construction | 2022 |
| B Blignaut Services Limited | Health & social care | 2022 |
| B Bootcamp Ltd | Other services | 2010 |
| B Fibre Installs Ltd | Information & communication | 2023 |
| B Osborne Estate Agents Limited | Real estate | 2025 |
| B&J Ashman Limited | Construction | 2022 |
| B&K Alliances Limited | Wholesale & retail | 2025 |
| B&O Developers Ltd | Construction | 2022 |
| B&R Investments Limited | Real estate | 2015 |
| B&S Driving School Limited | Other services | 2018 |
| B&S Driving Services Ltd | Education | 2024 |
| B. & M. Davis Limited | Wholesale & retail | 1976 |
| Baby Basics International Ltd | Wholesale & retail | 2020 |
| Baby Robins Limited | Health & social care | 2025 |
| Baby-Mother Care Ltd | Wholesale & retail | 2019 |
| Bacioaia Ltd | Construction | 2026 |
| Back Page Images Limited | Professional & scientific | 2004 |
| Bahari Investments Limited | Financial services | 2022 |
| Bakers Plumbing & Heating Services Ltd | Construction | 2012 |
| Balaji Chauffeur Service Limited | Transport & logistics | 2024 |
| Balaji Products Ltd | Wholesale & retail | 2024 |
| Balanova Limited | Manufacturing | 2022 |
| Ballards Lane (190/192) Management Limited | Real estate | 1975 |
| Ballistic Ballers CIC | Education | 2023 |
| Balmoral Enterprises Limited | Administrative & support | 2017 |
| Bambi Sports Bar Ltd | Hospitality | 2023 |
| Bame in Property Ltd | Professional & scientific | 2020 |
| Bamipro Limited | Real estate | 2019 |
| Banitti Ltd | Real estate | 2023 |
| Banner Capital Consultants Ltd | Real estate | 2024 |
| Bannerfy Ltd | Professional & scientific | 2023 |
| Bappa's Catering Service Ltd | Hospitality | 2023 |
| Barao Construction Ltd | Construction | 2018 |
| Barao Limited | Construction | 2020 |
| Barao Plant Hire Ltd | Administrative & support | 2019 |
| Baraozeca Properties Limited | Real estate | 2020 |
| Barari Properties Limited | Real estate | 2020 |
| Barbos Construction Ltd | Construction | 2023 |
| Bardot Ltd | Real estate | 2019 |
| Barfor Investments Ltd | Real estate | 2018 |
| Bargain Hunt Auctions Limited | Wholesale & retail | 2018 |
| BARGAIN247 Limited | Other services | 2015 |
| Barnes Lane Property Ltd | Administrative & support | 2025 |
| Barosa Property Limited | Real estate | 2019 |
| Barracuda Stanmore Ltd | Hospitality | 2017 |
| Barsal Property Limited | Real estate | 2025 |
| Barton Cuisines Ltd | Hospitality | 2019 |
| Barton Estate Developers Limited | Construction | 2024 |
| Basb Limited | Financial services | 2012 |
| Basilgreen Limited | Construction | 1983 |
| Basingstoke Skylight LLP | | 2016 |
| Basiret Consultants Limited | Real estate | 1986 |
| Batchworth Consulting Ltd | Professional & scientific | 2022 |
| Batemans ROW 1-6 RTM Company Limited | Households | 2025 |
| BATHROOMS2U Limited | Wholesale & retail | 2005 |
| Batul Trading Ltd | Other services | 2018 |
| Baum Mammon Ltd | Hospitality | 2016 |
| Baxter Rise Limited | Real estate | 2021 |
| Bay Retail Ltd | Wholesale & retail | 2020 |
| Bayham Street Financial Limited | Financial services | 2014 |
| Baypride Properties Limited | Real estate | 2009 |
| Bayt AL - ZAD Ltd | Wholesale & retail | 2026 |
| Bazaar Direct Limited | Wholesale & retail | 2023 |
| BB IPR Limited | Health & social care | 1997 |