| Austin and Carnley Solicitors Ltd | Professional & scientific | 2023 |
| Authentic Media Limited | Manufacturing | 2009 |
| Auto Atlas Ltd | Wholesale & retail | 2022 |
| Auto Atlas Services Ltd | Wholesale & retail | 2024 |
| Auto Inparts Limited | Wholesale & retail | 1988 |
| Auto Nation Logistics Limited | Transport & logistics | 2020 |
| Auto Retro Limited | Wholesale & retail | 2007 |
| Auto Select Motors Ltd | Wholesale & retail | 2018 |
| Auto Supplies International Ltd. | Wholesale & retail | 1994 |
| Autobox Machinery Ltd | Manufacturing | 2008 |
| Automotive Distribution Centre Limited | Wholesale & retail | 2021 |
| AV Wave Group Ltd | Administrative & support | 2024 |
| AV8 Consulting Limited | Real estate | 2023 |
| Avalon Cleaning Systems Limited | Other services | 2013 |
| Avalon DNA Group Limited | Financial services | 2026 |
| Avance Group Limited | Wholesale & retail | 2021 |
| Avart Communications Limited | Professional & scientific | 2023 |
| Aveline Court Management Limited | Households | 2000 |
| Averon Motors Limited | Wholesale & retail | 2025 |
| Avery Accomplished Property Limited | Real estate | 2022 |
| Avno Limited | Professional & scientific | 2025 |
| Avoke Limited | Wholesale & retail | 2012 |
| AVR K2U Sandhu's Limited | Wholesale & retail | 2022 |
| AW Electricity Limited | Extraterritorial | 2020 |
| AW Energy Limited | Other services | 2020 |
| AW Geothermal Limited | Other services | 2021 |
| AW Leisure Limited | Extraterritorial | 2020 |
| AW Renewables Holdings Limited | Administrative & support | 2020 |
| AW Skills Limited | Extraterritorial | 2020 |
| AWB Developments Ltd | Construction | 2017 |
| AWE (Owen) Limited | Professional & scientific | 2020 |
| AWE Renewables Limited | Energy | 2013 |
| Axiom Design Labs Ltd | Professional & scientific | 2026 |
| Aylesbury Scaffolding Limited | Construction | 2017 |
| Ayodele Health Care Ltd | Health & social care | 2025 |
| Ayré Studio Ltd | Arts & recreation | 2025 |
| AZ Used Cars LB Ltd | Wholesale & retail | 2017 |
| Azman Holdings Ltd | Other services | 2018 |
| Azzurriuk Ltd | Construction | 2020 |
| B & L Consulting Ltd | Information & communication | 2004 |
| B D Carpentry & Joinery Limited | Manufacturing | 2021 |
| B Impact Limited | Other services | 2023 |
| B&B QP Serviced Ltd | Professional & scientific | 2020 |
| B&Z Metalcraft Ltd | Manufacturing | 2013 |
| B. & V. Properties Limited | Real estate | 1960 |
| B. W Decorating Services Limited | Construction | 2009 |
| B.Allan Transport Ltd | Transport & logistics | 2015 |
| B.S. Trailer Services Limited | Administrative & support | 1997 |
| B/E Aerospace (UK) Limited | Other services | 1998 |
| B2B Assets Ltd | Construction | 2026 |
| Babington Education Organisation (UK) Limited | Education | 2025 |
| Babybean Limited | Wholesale & retail | 2024 |
| Baglio Ltd | Wholesale & retail | 2015 |
| Bagshawe BLOCK3 Freehold Ltd | Households | 2024 |
| Bailey Asset Management Limited | Real estate | 2026 |
| BAK (LB) Properties Limited | Households | 2026 |
| Bakehouse Mews (Freehold) Limited | Households | 2016 |
| Bakht Cyber Consulting Ltd | Information & communication | 2024 |
| Balanced Books Accountancy Services Ltd | Professional & scientific | 2012 |
| Bald Buzzard Ltd | Hospitality | 2022 |
| Baldwin's Motors Limited | Wholesale & retail | 2013 |
| Balguard Engineering Limited | Manufacturing | 1977 |
| Ball Electronics Limited | Manufacturing | 2019 |
| BAM Tender Solutions Limited | Professional & scientific | 2025 |
| Bambanani Ltd | Professional & scientific | 2021 |
| Bambino Community Nursery (Aylesbury) Limited | Health & social care | 2003 |
| Bambino Day Nurseries Limited | Health & social care | 1996 |
| Bamboo Growve Limited | Information & communication | 2024 |
| Bamboo Growve Network Limited | Other services | 2024 |
| Bandit Apparel Limited | Wholesale & retail | 2020 |
| Banscombe Ltd | Information & communication | 2021 |
| Banwell Place Management Limited | Households | 2014 |
| Bar Jewellery Ltd | Manufacturing | 2015 |
| Barada Food Ltd | Hospitality | 2025 |
| Barbara Grell Consultancy Limited | Information & communication | 2016 |
| Barchester Residents Company Limited | Households | 1989 |
| Bardelice Limited | Administrative & support | 2022 |
| Bare Minimum Ltd | Professional & scientific | 2020 |
| Barefoot Solutions Ltd | Information & communication | 2024 |
| Barge Information Management Limited | Professional & scientific | 1998 |
| Barking MAD Whatever the Weather Ltd | Agriculture & fishing | 2023 |
| Barneys Corner Ltd | Wholesale & retail | 2024 |
| Barran DTS Limited | Information & communication | 2025 |
| Bars in Beds Limited | Hospitality | 2013 |
| BAS4 Limited | Information & communication | 2022 |
| Basmile Engineering Limited | Professional & scientific | 1984 |
| Bassett Court RTM Company Limited | Households | 2014 |
| Bastech Trade Limited | Wholesale & retail | 2020 |
| Bay-Yoga Studio Ltd | Arts & recreation | 2024 |
| Bayes Ltd | Information & communication | 2026 |
| Bazil Enterprise Ltd. | Real estate | 2023 |
| BBB Machining Solutions Limited | Construction | 2015 |
| BBM (Bonsor Bricks & Mortar) Limited | Real estate | 2016 |
| BC Data Management Limited | Administrative & support | 2017 |
| Bcrest Limited | Wholesale & retail | 2004 |
| BE Fully Human Ltd | Professional & scientific | 2019 |
| Bear Hind the Scenes Limited | Information & communication | 2021 |
| Bearprops Ltd | Information & communication | 2018 |
| Bears IT Ltd | Information & communication | 2023 |
| Bearwolf Group Ltd | Wholesale & retail | 2024 |