| Affinity Motor Company Ltd | Wholesale & retail | 2025 |
| Affinity Roofing Banbury Ltd | Construction | 2025 |
| Affordable Hearing Care Ltd | Wholesale & retail | 2025 |
| Affordable Hearing Ltd | Wholesale & retail | 2022 |
| Afsar Buildings Ltd | Real estate | 2023 |
| AG Production (Oxfordshire) Limited | Information & communication | 2013 |
| AG Promotional Products Ltd | Wholesale & retail | 2019 |
| AGA Realty Ltd | Real estate | 2026 |
| Agavis Limited | Professional & scientific | 2025 |
| Agenais Limited | Financial services | 2018 |
| Agenais Trustees Limited | Professional & scientific | 2024 |
| AGF Contract Solutions Limited | Information & communication | 2023 |
| Aggy's Limited | Construction | 2006 |
| Agileboard Power AI Ltd | Information & communication | 2020 |
| Agility Wise Ltd | Other services | 2016 |
| Agilysis Limited | Information & communication | 2017 |
| Aglea UK Limited | Wholesale & retail | 2020 |
| Agora Systems Ltd | Information & communication | 2025 |
| AGS Security Management Ltd | Public administration | 2007 |
| Ahmed Generals Ltd | Hospitality | 2020 |
| Aikq Global Services Limited | Hospitality | 2019 |
| Aina Ltd | Real estate | 2016 |
| AIO Consulting Limited | Professional & scientific | 2016 |
| Air Medic U.K. Ltd | Health & social care | 2020 |
| Airhost Direct Ltd | Other services | 2021 |
| Airport Taxi Banbury Ltd | Transport & logistics | 2024 |
| AJ Carpentry & Building Services Ltd | Construction | 2025 |
| AJ Swati Ltd | Wholesale & retail | 2026 |
| Ajnm Property Limited | Real estate | 2018 |
| AJP Camera Ltd | Professional & scientific | 2020 |
| AK Elite Construction Ltd | Construction | 2025 |
| Ak&Cc Ltd | Administrative & support | 2017 |
| AKA EN Ltd | Hospitality | 2020 |
| Akeem Drew Changing Lives Ltd | Administrative & support | 2026 |
| AKM Software Development Limited | Information & communication | 2024 |
| AL Barka Foods Limited | Hospitality | 2020 |
| AL Shaam Athenaeum Limited | Wholesale & retail | 2024 |
| Alan Creighton Racing Ltd | Arts & recreation | 2025 |
| Alasdair Lowe Ltd | Agriculture & fishing | 2002 |
| Albatron Science Limited | Wholesale & retail | 2010 |
| Albion (Oxon) Limited | Education | 1991 |
| Albion Fine Art Ltd | Wholesale & retail | 2013 |
| Alchemist Designs Ltd | Professional & scientific | 2018 |
| Alderwood Electrical Limited | Manufacturing | 1999 |
| Aleksi Trans Ltd | Transport & logistics | 2019 |
| Alex Lawrie Factors Limited | Extraterritorial | 1971 |
| Alex Rowley Limited | Agriculture & fishing | 2003 |
| Alex&Beta Logistics Ltd | Transport & logistics | 2017 |
| Alex. Lawrie Receivables Financing Limited | Extraterritorial | 1970 |
| Alexander Cohane Limited | Wholesale & retail | 2006 |
| Alexander Construction (Oxfordshire) Limited | Construction | 2012 |
| Alexandra Properties (Oxon) Limited Liability Partnership | | 2008 |
| Alexis Logistics Ltd | Transport & logistics | 2021 |
| Alfabyt Limited | Hospitality | 2026 |
| Alice Milburn-Foster Ltd | Arts & recreation | 2022 |
| Alice Sykes Limited | Professional & scientific | 2015 |
| Alien Bespoke Solutions Limited | Information & communication | 2019 |
| Alienware Ltd | Hospitality | 2025 |
| Alina’S Cleaning Solutions Ltd | Administrative & support | 2025 |
| Alison Hallford Partnership Limited | Professional & scientific | 2004 |
| Alitech Limited | Information & communication | 2023 |
| ALL Aces Couriers Limited | Financial services | 2025 |
| ALL Aces Haulage Ltd | Transport & logistics | 2026 |
| ALL DRY Ltd | Hospitality | 2015 |
| ALL DRY Prop Co Ltd | Real estate | 2015 |
| ALL Indie Limited | Other services | 2006 |
| ALL Plants Euro Haulage Ltd | Transport & logistics | 2026 |
| ALL Seasons Hotels Ltd | Hospitality | 2014 |
| Allan Contracting Services Ltd | Manufacturing | 2024 |
| Allbright Electric Co.Limited | Real estate | 1932 |
| Allbright Properties Limited | Real estate | 1980 |
| Allergy Advisor App Ltd | Information & communication | 2025 |
| Alliance Management & Consultancy Ltd | Professional & scientific | 2020 |
| Allicia Haynes Ltd | Transport & logistics | 2025 |
| Allison Fountains Ltd | Manufacturing | 2003 |
| Allman Horrocks Consulting Limited | Professional & scientific | 1996 |
| Allsafe Scaffolding (East Midlands) Limited | Construction | 2025 |
| Alma Road (Banbury) RTM Company Ltd | Households | 2012 |
| Almanaasik Tours Limited | Administrative & support | 2012 |
| Alper ZAN Consultancy Limited | Professional & scientific | 2024 |
| Alpha Realty Limited | Real estate | 1993 |
| Alphabronx Limited | Information & communication | 2008 |
| Alphazon Ltd | Wholesale & retail | 2025 |
| Altbet Limited | Arts & recreation | 2014 |
| Altium Investment Management Limited | Financial services | 2018 |
| Alun Darbyshire Limited | Arts & recreation | 2023 |
| Alvic Consultancy Limited | Administrative & support | 2014 |
| Always Everything Ltd | Wholesale & retail | 2023 |
| AM Orthopaedic Solutions Limited | Health & social care | 2025 |
| Amai K Collective Ltd | Professional & scientific | 2025 |
| Amazing Electrical Limited | Administrative & support | 2025 |
| Amazing Home Solutions Ltd | Construction | 2021 |
| Amazing Lofts (Storage Solutions) Ltd | Construction | 2020 |
| Ambassador Cars (Oxon) Ltd | Transport & logistics | 2023 |
| Amber Photographics Limited | Professional & scientific | 2010 |
| Amer Asiri Food & Beverage Ltd | Wholesale & retail | 2025 |
| AMF Trans Limited | Transport & logistics | 2021 |
| Amnb Ltd | Construction | 2014 |
| Ampersand Dairy Ltd | Manufacturing | 2019 |
| Ampersand Studio Oxon Ltd | Information & communication | 2022 |