| Andrew Field Electrical Limited | Construction | 2005 |
| Andy Wilson Limited | Professional & scientific | 2024 |
| Angelic Music Publishing Limited | Professional & scientific | 2002 |
| Angelic Record Productions Limited | Construction | 1996 |
| Angelic Records Limited | Professional & scientific | 2002 |
| Anita Brook Property Ltd | Real estate | 2017 |
| Anna Gomez Ltd | Other services | 2026 |
| AP Creative Co Studio Ltd | Professional & scientific | 2021 |
| AP Plumbing & Bathrooms Limited | Construction | 2015 |
| AP Psychology Services Ltd | Health & social care | 2016 |
| APC Taylor Limited | Administrative & support | 2024 |
| Appleton & Lewis Accountants Ltd | Professional & scientific | 2026 |
| Applied EV UK Ltd | Administrative & support | 2022 |
| Aptus Housing Ltd | Real estate | 2026 |
| Aqua Lamoda Ltd | Wholesale & retail | 2023 |
| Aquaskipper UK Limited | Extraterritorial | 2006 |
| Aquasure Solutions Ltd | Water & waste | 2025 |
| Arcadian Properties Ltd | Real estate | 2002 |
| Ardent Paint Care Limited | Wholesale & retail | 2015 |
| Argy Properties Ltd | Real estate | 2021 |
| Arianne Design Studio Limited | Real estate | 2014 |
| Aries UK Logistics and Transport Ltd | Transport & logistics | 2024 |
| Armitage Airsoft Ltd | Extraterritorial | 2025 |
| Armitage Automotive Ltd | Wholesale & retail | 2025 |
| Armitage Online Limited | Wholesale & retail | 2022 |
| Arniston Holdings Limited | Financial services | 2022 |
| Art of Action Productions Ltd | Information & communication | 2024 |
| Arthey Paper Designs Ltd | Manufacturing | 2023 |
| Artigian Limited | Wholesale & retail | 2024 |
| AS Medics Limited | Professional & scientific | 2015 |
| Asar Construction Ltd | Construction | 2018 |
| ASB Operations Consulting Ltd | Professional & scientific | 2020 |
| ASF Holding Company Limited | Financial services | 2024 |
| ASF Projects Limited | Administrative & support | 2020 |
| Asio-X Ltd | Health & social care | 2014 |
| ASK HEN Ltd. | Information & communication | 2013 |
| Aslan Fine Plaster Craft Ltd | Manufacturing | 2024 |
| Aspect Construction (Brackley) Ltd | Construction | 2022 |
| Assurion Facilities & Compliance Ltd | Administrative & support | 2026 |
| AST Suspension UK Ltd | Wholesale & retail | 2023 |
| Aster International Limited | Wholesale & retail | 2001 |
| Astimo Ltd | Professional & scientific | 2006 |
| Astralytics Limited | Information & communication | 2015 |
| Astrid Data Protection Limited | Information & communication | 2018 |
| Astrop Consultants Ltd | Professional & scientific | 2011 |
| Astwell Castle Farm Limited | Agriculture & fishing | 1956 |
| ATD Contracting Ltd | Professional & scientific | 2025 |
| Atec Autotechnic Limited | Wholesale & retail | 1997 |
| Atec Fluid Systems Limited | Manufacturing | 2012 |
| Ateh Jewel Beauty Limited | Wholesale & retail | 2019 |
| Atlas Asset Investments Limited | Real estate | 2023 |
| Atriox Broadcast Ltd | Information & communication | 2023 |
| Audacia Investment Limited | Construction | 2017 |
| Aura Aesthetics Brackley Limited | Other services | 2025 |
| Aurora Technical Ltd. | Information & communication | 2015 |
| Auto B U D D Limited | Wholesale & retail | 2024 |
| Auto BUD Limited | Wholesale & retail | 2025 |
| Avara Foods Holdings Limited | Financial services | 2017 |
| Avara Foods Limited | Manufacturing | 2017 |
| Avce Properties Limited | Real estate | 2020 |
| Avid Property Ltd | Construction | 2023 |
| Avos Auto Exports Limited | Wholesale & retail | 2020 |
| Avos Auto Solutions Ltd | Wholesale & retail | 2020 |
| Axycad Homes Ltd | Real estate | 2023 |
| Axycad Ltd | Construction | 2017 |
| Azalea Healthcare Limited | Health & social care | 2022 |
| Azure Window Cleaning Limited | Administrative & support | 2024 |
| B K F Designs Limited | Manufacturing | 2009 |
| B.S. Supplies (Stoke-On-Trent) Limited | Manufacturing | 2001 |
| Banbury Catering (Commercial) Limited | Hospitality | 2012 |
| Banbury Gliding Club Limited | Arts & recreation | 1979 |
| Banbury Paint Solutions Limited | Wholesale & retail | 2020 |
| Bar 212 Coffee Shop & Wine Bar Ltd | Hospitality | 2025 |
| Barbers 27 Ltd | Other services | 2023 |
| Barden Refrigeration Services Oxford Limited | Manufacturing | 2014 |
| Barley MOW Consulting Limited | Information & communication | 2026 |
| Barlow Films Limited | Information & communication | 2008 |
| Barncorp Limited | Real estate | 2022 |
| Barnship Limited | Professional & scientific | 1995 |
| Baron Independent Financial Services Ltd | Professional & scientific | 2021 |
| Baron Independent Traders Limited | Construction | 2015 |
| Barr-Walthom Limited | Professional & scientific | 2022 |
| Barrington Mews RTM Company Limited | Extraterritorial | 2014 |
| Barrique Limited | | 1975 |
| BAS Training Associates Limited | Education | 2013 |
| Basfords Garage Limited | Wholesale & retail | 2011 |
| Basking Babies Baby Massage Limited | Extraterritorial | 2014 |
| Basking Babies IP Ltd | Extraterritorial | 2014 |
| Basking Babies Limited | Wholesale & retail | 2014 |
| Bay Automotive Limited | Wholesale & retail | 2012 |
| Bayliss Bespoke Designs Ltd | Arts & recreation | 2021 |
| BB Fire Ltd | Public administration | 2018 |
| BBR GTI Limited | Wholesale & retail | 2010 |
| BBR Performance Limited | Wholesale & retail | 2021 |
| BC 36 Ltd | Hospitality | 2024 |
| BCH Management Company Ltd | Real estate | 2022 |
| BCW Property Ltd | Real estate | 2025 |
| BCW Repair Centre Limited | Wholesale & retail | 1995 |
| Beast Branded Content Limited | Information & communication | 2015 |
| Bee-Yond Ecology CIC | Professional & scientific | 2024 |