| 100 Platform Ltd | Arts & recreation | 2025 |
| 105 ST George's Square Limited | Households | 2007 |
| 115 Byrne Road Residents Limited | Extraterritorial | 2009 |
| 17 Chelsea Court Limited | Real estate | 2015 |
| 18 Anhalt Road Ltd | Agriculture & fishing | 2016 |
| 18 Horsefair Management Limited | Real estate | 2015 |
| 2 School Gardens Management Company Limited | Households | 2003 |
| 20-22 Consulting Limited | Professional & scientific | 2022 |
| 2001 Products Ltd | Wholesale & retail | 2022 |
| 2045 Consulting Ltd | Information & communication | 2025 |
| 247 Mesh Ltd | Information & communication | 2023 |
| 268 Leisure & Hospitality Ltd | Professional & scientific | 2024 |
| 32 Brompton Square RTM Company Limited | Households | 2021 |
| 3CS Cider Limited | Manufacturing | 2013 |
| 3D Wise Ltd | Professional & scientific | 2019 |
| 3DS Engineering Limited | Professional & scientific | 2018 |
| 3XM Productions Ltd | Arts & recreation | 2021 |
| 46 Mortimer Drive Marston (Oxford) Management Co Limited | Households | 2006 |
| 4CAUSE Limited | Professional & scientific | 2022 |
| 4PWC Ltd | Information & communication | 2022 |
| 5 Mill LLP | | 2017 |
| 75 Consultancy Ltd | Professional & scientific | 2025 |
| 78 Tremadoc Road Management Limited | Households | 2003 |
| 88NORTH Consulting Ltd | Professional & scientific | 2019 |
| A C Dinardo Limited | Professional & scientific | 2020 |
| A Cars Chipping Norton Ltd | Transport & logistics | 2026 |
| A M Greenaway Ltd | Wholesale & retail | 2017 |
| A Step TOO FAR Productions Ltd | Information & communication | 2024 |
| A. L. Sole & SON Limited | Other services | 2014 |
| A2D Estates Ltd | Administrative & support | 2016 |
| Aaawesome Contracting Ltd | Information & communication | 2026 |
| Aaawesome Group Ltd | Professional & scientific | 2025 |
| Aaawesome Networks Ltd | Professional & scientific | 2025 |
| Aaris Limited | Information & communication | 2014 |
| AB Equine Transport Ltd | Transport & logistics | 2020 |
| Abishop Ltd | Education | 2024 |
| Absolute Chipping Norton Holding Ltd | Health & social care | 2026 |
| Absolute Chipping Norton Ltd | Health & social care | 2026 |
| Absolutely Organic Limited | Wholesale & retail | 2000 |
| Abtv Productions Limited | Information & communication | 2013 |
| Acorn Technical Consulting Limited | Administrative & support | 2008 |
| Acquisition Assist Limited | Extraterritorial | 2022 |
| Active England Tours Ltd | Administrative & support | 2008 |
| Active Outdoor and SKI Limited | Transport & logistics | 2007 |
| Acuron Ltd | Professional & scientific | 2026 |
| Adam Samuel Ward Limited | Information & communication | 2021 |
| Address Logic Ltd | Administrative & support | 2015 |
| ADK LAB Limited | Information & communication | 2018 |
| Advise Assist Consulting Ltd | Professional & scientific | 2021 |
| Aerial Media Limited | Information & communication | 2014 |
| Aerialsat Services Ltd | Information & communication | 2019 |
| AFA Gallery CIC | Wholesale & retail | 2023 |
| Affineti Limited | Information & communication | 2009 |
| After Hours Collective Ltd | Information & communication | 2026 |
| AHB Associates Ltd | Professional & scientific | 2024 |
| Ahmed CN Ltd | Hospitality | 2019 |
| Ahmed Holy Properties Ltd | Real estate | 2024 |
| AI Centre for Business Limited | Other services | 2026 |
| AKA Caterers Limited | Hospitality | 1997 |
| Alan Howard Design Limited | Information & communication | 2009 |
| Albion House Albion Street Management Company Limited | Real estate | 2013 |
| Aldridge Scrap Metal Limited | Water & waste | 2013 |
| Alejandro Equestrian Limited | Agriculture & fishing | 1994 |
| Alfred Groves & Sons Limited | Wholesale & retail | 1930 |
| Alice Powell Racing Limited | Arts & recreation | 2009 |
| ALL Tyres (Oxford) Limited | Wholesale & retail | 2012 |
| Allegro Moderato Limited | Professional & scientific | 2020 |
| Allen Ventures Services UK Ltd | Professional & scientific | 2020 |
| Allfox Consulting Limited | Wholesale & retail | 2024 |
| Allsports Nutrition Limited | Wholesale & retail | 1987 |
| Alpine Racing Limited | Arts & recreation | 1984 |
| ALR Search Ltd | Administrative & support | 2023 |
| Alto Cerrado Ltd | Real estate | 2021 |
| Amanda Helen Brown Limited | Extraterritorial | 2024 |
| Amanda Helen Clarke Limited | Extraterritorial | 2024 |
| Amaryllis Publishing Limited | Information & communication | 2012 |
| Amiable Marketing & Consulting Ltd | Professional & scientific | 2018 |
| Amicus Films Ltd | Information & communication | 2014 |
| Andrea Ortona Violins Ltd | Manufacturing | 2019 |
| Angaston Properties Ltd | Real estate | 2025 |
| Angelus Bidco Limited | Financial services | 2024 |
| Angelus Midco Limited | Financial services | 2024 |
| Angelus Nomineeco Limited | Financial services | 2024 |
| Angelus Topco Limited | Financial services | 2024 |
| Angus W Taylor Limited | Professional & scientific | 2019 |
| Anita Wadley Ltd | Professional & scientific | 2013 |
| ANY Ventures Ltd | Wholesale & retail | 2026 |
| Aplty Limited | Construction | 2025 |
| Approach Geophysics Ltd | Professional & scientific | 2004 |
| APS Heating & Plumbing Ltd | Construction | 2025 |
| ARC Homes NW Ltd | Real estate | 2026 |
| Architology Ltd | Professional & scientific | 2019 |
| Archivist Trustees Limited | Professional & scientific | 2025 |
| Arco Hospitality Ltd | Hospitality | 2023 |
| Arkel Limited | Financial services | 2017 |
| Arktos Blenheim Consulting Limited | Professional & scientific | 2024 |
| Armatos Ltd | Professional & scientific | 2014 |
| Armstrong Coaching & Consulting Limited | Professional & scientific | 2009 |
| Art Computing Limited | Information & communication | 2002 |
| Arthq Group Limited | Professional & scientific | 2020 |