| Archie Watson Racing Limited | Arts & recreation | 2016 |
| Archivo Limited | Information & communication | 2006 |
| Ariadne Strategy Ltd | Professional & scientific | 2025 |
| Arnold, Jones & Denne Limited | Real estate | 2016 |
| Arquette Media Ltd | Information & communication | 2017 |
| Arrowdown Equine Vets Limited | Professional & scientific | 2025 |
| Arrrrrrrgh Ltd | Hospitality | 2025 |
| Arscott Property Limited | Real estate | 2014 |
| Arslan Restaurant Limited | Hospitality | 2026 |
| Artisan Cocktails Ltd | Wholesale & retail | 2026 |
| Arts for Hungerford Community Interest Company | Arts & recreation | 2016 |
| Ascensio Consulting Ltd | Information & communication | 2014 |
| Ashley Brow Bar Ltd | Other services | 2016 |
| Ashley James Medical (Phec) Limited | Health & social care | 2026 |
| Ashridge Wokingham Limited | Real estate | 2021 |
| Aspire Contractors Limited | Professional & scientific | 2019 |
| Aspire Poole Limited | Professional & scientific | 2016 |
| Asset Monitoring Solution Group (UK) Limited | Information & communication | 2009 |
| Asset Plus One Limited | Professional & scientific | 1999 |
| Astraea Mediation Ltd | Professional & scientific | 2023 |
| Astranet Limited | Construction | 2014 |
| Astrapi CRM Solutions Ltd | Information & communication | 2025 |
| Astrea Holdings Limited | Financial services | 2025 |
| Astrea London Holdings Limited | Financial services | 2025 |
| Atelier Trickey Project Architecture Limited | Professional & scientific | 2021 |
| Athawes Estates UK Limited | Extraterritorial | 2025 |
| Audio Visual Excellence Limited | Information & communication | 2011 |
| Augprop Limited | Real estate | 2024 |
| Aulakh Fish & Chips Limited | Hospitality | 2024 |
| AVO Holdings Limited | Financial services | 2024 |
| AW86 Limited | Information & communication | 2022 |
| Awkward Monkey Productions Ltd | Information & communication | 2020 |
| AWR IT Consulting Limited | Information & communication | 2019 |
| B & G Talmage Limited | Construction | 2005 |
| B & M Productions Ltd | Arts & recreation | 2025 |
| B H Ding'Er Limited | Wholesale & retail | 2020 |
| B S Povey 1 Limited | Professional & scientific | 2009 |
| B-Secure Consulting Limited | Professional & scientific | 2025 |
| B.S. Povey (Winterbourne) Limited | Agriculture & fishing | 1959 |
| B.W. Hills Southbank Limited | Arts & recreation | 1977 |
| Backstop OMC Ltd. | Households | 2015 |
| Bailey Robinson Holdings Limited | Professional & scientific | 2010 |
| Baker & Mcveigh Lambourn Limited | Professional & scientific | 2016 |
| Balfour Martin Ltd | Professional & scientific | 2016 |
| Ballymaw Bloodstock Ltd | Agriculture & fishing | 2022 |
| Bampfylde Street Cafe Ltd | Hospitality | 2021 |
| Barchester Estates Ltd | Real estate | 2017 |
| Barchester Properties Ltd | Real estate | 2014 |
| Bare Naked Money Limited | Financial services | 2022 |
| Barolhurst Resources Limited | Wholesale & retail | 1982 |
| Basil Properties Limited | Real estate | 2021 |
| BBB Talent Casting Limited | Administrative & support | 2022 |
| Beech Breaker Limited | Real estate | 2019 |
| Bellstone Holdings Limited | Hospitality | 2021 |
| BEN Austin Civil Engineering Ltd | Professional & scientific | 2017 |
| Benaco Media Ltd | Administrative & support | 2020 |
| Benchmark Furniture Limited | Real estate | 1995 |
| Benchmark Woodworking Limited | Manufacturing | 1986 |
| Benham Pest Control Services Limited | Professional & scientific | 2017 |
| Benmichaelco Ltd | Construction | 2024 |
| Benney International Limited | Manufacturing | 2013 |
| Berkshire Direct Cleaning Services Ltd | Administrative & support | 2026 |
| Berkshire Labels Limited | Manufacturing | 1987 |
| Berkshire POP Tops Ltd | Manufacturing | 2026 |
| Berkshire Property Renovations Limited | Construction | 2022 |
| Berkshire Trout Farm Limited | Agriculture & fishing | 1979 |
| Better Business Decisions Limited | Administrative & support | 2023 |
| Better Engineering Ltd | Manufacturing | 2022 |
| Blackbox Platform Ltd | Information & communication | 2015 |
| Bleu Azure Limited | Wholesale & retail | 2009 |
| Blue Flame Media Ltd | Professional & scientific | 2021 |
| Blue Sky Folk Ltd | Arts & recreation | 2023 |
| Blueora Ltd | Financial services | 2024 |
| Boat Fittings Ltd | Wholesale & retail | 2017 |
| Bonchurch Freehold Management Company Limited | Households | 2024 |
| Bonyhub Limited | Wholesale & retail | 2021 |
| Boomerang Stables Limited | Arts & recreation | 2017 |
| Boundless Partners Limited | Professional & scientific | 2024 |
| Brettargh Limited | Professional & scientific | 2026 |
| Bright Point Software Ltd | Information & communication | 2026 |
| Broad ROW Books Limited | Information & communication | 2019 |
| Broadmead Estates (Prospect Road) Limited | Real estate | 2002 |
| Broadmead Estates Limited | Administrative & support | 1986 |
| Broadmead Park Leisure Limited | Administrative & support | 1988 |
| Bromarpeak Limited | Real estate | 1974 |
| Bronson U.S. Law Services Limited | Professional & scientific | 2025 |
| Brontofarm Ltd | Information & communication | 2020 |
| Brown Dog Financial Planning Limited | Professional & scientific | 2015 |
| Brown Industrial Control Systems Limited | Administrative & support | 2008 |
| Bsum Limited | Professional & scientific | 2018 |
| Built by Titanium Ltd | Other services | 2023 |
| Bulkdress Limited | Wholesale & retail | 2026 |
| Bullingdon Construction Limited | Construction | 2025 |
| Bumper Consulting Ltd | Professional & scientific | 2020 |
| Bumper Holdings Ltd | Financial services | 2023 |
| Burnard EBS Limited | Construction | 2005 |
| Burnt Oak 3S Ltd | Arts & recreation | 2024 |
| BY Kindly Ltd | Construction | 2021 |
| Bywater Investments Limited | Financial services | 2022 |
| Bywater Management Limited | Financial services | 2022 |