| Auto Easy Network Limited | Wholesale & retail | 2021 |
| Auto Express (Rugby) Limited | Wholesale & retail | 2024 |
| Auto Feas Limited | Professional & scientific | 2015 |
| Auto Learner Ltd | Education | 2023 |
| Auto Roam Ltd | Wholesale & retail | 2024 |
| Autobahn Servicing Halesowen Ltd. | Wholesale & retail | 2013 |
| Autocom Invest Ltd | Transport & logistics | 2026 |
| Autodiag Ltd | Wholesale & retail | 2019 |
| Autoeconnect Limited | Information & communication | 2023 |
| Autohouserugby Ltd | Wholesale & retail | 2023 |
| Autokeys (Midland) Ltd | Administrative & support | 2011 |
| Autolines Inc Ltd | Transport & logistics | 2021 |
| Autolund Ltd | Manufacturing | 2024 |
| Automatic Enrolment Solutions Limited | Financial services | 2015 |
| Automation and Logistics Ltd | Administrative & support | 2022 |
| Automatt Ltd | Transport & logistics | 2018 |
| Automead Limited | Wholesale & retail | 2011 |
| Automotive Engineering Management Limited | Professional & scientific | 2023 |
| Automotive Insulations Limited | Professional & scientific | 2002 |
| Automotive Paint Repairs Limited | Wholesale & retail | 2013 |
| Autopa Limited | Manufacturing | 1997 |
| Autosculpt Design Limited | Professional & scientific | 1996 |
| Autosculpt Ltd | Professional & scientific | 2023 |
| AV Aerospace Ltd | Professional & scientific | 2022 |
| Av@Omfs Ltd | Health & social care | 2021 |
| Avaiya Limited | Health & social care | 2016 |
| Avalon Homes & Developments Ltd | Construction | 2023 |
| Avancer Consult Ltd | Information & communication | 2015 |
| Avdhoot Ltd | Professional & scientific | 2021 |
| Aviation Work Support Limited | Administrative & support | 2010 |
| Avid Stacc Ltd | Manufacturing | 2015 |
| AVK Traders Limited | Wholesale & retail | 2023 |
| AVM Care Limited | Health & social care | 2025 |
| Avon Carrow Securities Limited | Professional & scientific | 1978 |
| Avon Home Improvements Ltd | Construction | 2021 |
| Avon Joinery Holdings Limited | Financial services | 2019 |
| Avon Joinery Limited | Manufacturing | 1994 |
| Avondale Farm & Stables Ltd | Agriculture & fishing | 2022 |
| AW Automotive Products Ltd | Wholesale & retail | 2000 |
| AW Haul-It Ltd | Transport & logistics | 2026 |
| Awesmart Ventures Limited | Wholesale & retail | 2015 |
| AWM Electrical Service Group Limited | Construction | 2010 |
| AXE Capital FS Ltd | Financial services | 2016 |
| Axel 2025 Ltd | Transport & logistics | 2025 |
| Axis of Impact Ltd | Professional & scientific | 2025 |
| Ayaanika Estates Ltd | Real estate | 2026 |
| Ayesha Community School Limited | Education | 2009 |
| Ayjit Ltd | Transport & logistics | 2020 |
| Aykizi Limited | Hospitality | 2024 |
| Azmar Mini Market Ltd | Wholesale & retail | 2025 |
| Azmer Mini Market Ltd | Wholesale & retail | 2026 |
| Azzin Holdings Limited | Real estate | 2019 |
| B & G Personnel Limited | Health & social care | 2017 |
| B B Building & Timber Merchants Limited | Wholesale & retail | 2010 |
| B B Fencing Limited | Construction | 1996 |
| B Cazul Ltd | Real estate | 2024 |
| B J Devlin Limited | Transport & logistics | 2019 |
| B R Consultancy Services Ltd | Health & social care | 2022 |
| B Yoga Limited | Arts & recreation | 2015 |
| B&Cwc Limited | Professional & scientific | 2020 |
| B&H Midlands Ltd | Construction | 2022 |
| B-Lands Consulting Ltd | Extraterritorial | 2019 |
| B.Cheshire Limited | Arts & recreation | 2011 |
| B.Collinson Ltd | Households | 2026 |
| B.E. Wright CAD Development Limited | Information & communication | 2017 |
| B.E.A.R.S Security Ltd | Administrative & support | 2019 |
| B.O. Reilly & Sons Limited | Water & waste | 2002 |
| B.S.S Roofing & Scaffolding Ltd | Construction | 2019 |
| B1 Professional Cafe Limited | Hospitality | 2025 |
| B3 Web Solutions Limited | Information & communication | 2018 |
| BA 1896 Limited | Real estate | 2025 |
| BA Real Estate Limited | Real estate | 2022 |
| Baader (U.K.) Limited | Manufacturing | 1975 |
| Baba-Q Grill Ltd | Hospitality | 2019 |
| Babama Properties Limited | Real estate | 2021 |
| Baboush Hotel Restaurant PUB Limited | Hospitality | 2023 |
| Babs Group Ltd | Wholesale & retail | 2023 |
| Bacall Ltd | Real estate | 2002 |
| Bach Flower Kingdom Limited | Other services | 2024 |
| Backwith Music Limited | Arts & recreation | 2013 |
| Bacu Trans Ltd | Transport & logistics | 2024 |
| Bada Spedition Ltd | Transport & logistics | 2026 |
| Badea Transport Ltd | Transport & logistics | 2018 |
| Badger Plant Training Ltd | Education | 2024 |
| BAF Nutrition Ltd | Wholesale & retail | 2018 |
| Bafana Digital Services Limited | Information & communication | 2026 |
| Bagile Limited | Information & communication | 2020 |
| Bagoo Homes Ltd | Wholesale & retail | 2021 |
| Bains Sisters Limited | Extraterritorial | 2017 |
| Bajrang Holdings Ltd | Real estate | 2026 |
| BAK Consultancy Services Limited | Administrative & support | 2023 |
| BAK Westfield Limited | Construction | 2023 |
| Baked Bakery UK Ltd | Wholesale & retail | 2022 |
| Baked Brownies UK Ltd | Hospitality | 2023 |
| Baked Coffee House Ltd | Hospitality | 2026 |
| Bakehouse Boxing & Martial Arts Ltd | Arts & recreation | 2015 |
| Bakehouse Community Boxing & Wellbeing CIC | Arts & recreation | 2025 |
| Bakehouse Property Ltd | Real estate | 2023 |
| Baker Harman & Co LLP | | 2026 |
| Baker Harman AM Limited | Real estate | 2026 |