| Abingdon Marina Residents' Association Limited | Professional & scientific | 2002 |
| Abingdon Nails Ltd | Other services | 2023 |
| Abingdon Natural Health and Therapy Centre Ltd | Health & social care | 2018 |
| Abingdon Nurseries Limited | Education | 2005 |
| Abingdon Oak Ltd | Construction | 2019 |
| Abingdon Residents Company Limited | Households | 2005 |
| Abingdon Riverside Cafe Ltd | Hospitality | 2023 |
| Abingdon School | Education | 1998 |
| Abingdon School Enterprises Limited | Education | 2002 |
| Abingdon Services Limited | Construction | 2016 |
| Abingdon Specsavers Limited | Wholesale & retail | 1992 |
| Abingdon Thai Massage Limited | Health & social care | 2026 |
| Abingdon Therapy and Mediation Service C.I.C. | Health & social care | 2026 |
| Abingdon Travel Ltd | Transport & logistics | 2019 |
| Abingdon Vale Ltd | Hospitality | 2024 |
| Abingdon Vehicle Services Limited | Wholesale & retail | 2003 |
| Abingdon Verification Instruments Ltd | Manufacturing | 2021 |
| Abingdon Visionplus Limited | Wholesale & retail | 1992 |
| Abingdon Wood Yard Ltd | Wholesale & retail | 2021 |
| Abingplough Ltd | Hospitality | 2024 |
| Abiwholefoods Ltd | Administrative & support | 2014 |
| Abotra Ltd | Information & communication | 2007 |
| Absl Power Solutions Ltd | Manufacturing | 1993 |
| Absolute Divorce Limited | Extraterritorial | 2003 |
| AC Artwork Creative Ltd | Extraterritorial | 2015 |
| Acacia UK (Trading) Limited | Wholesale & retail | 1997 |
| Academic Anaesthesia Limited | Extraterritorial | 2005 |
| Academy of Coaching & Training Ltd | Financial services | 2011 |
| Academyline Corporate Limited | Transport & logistics | 2008 |
| ACB IT Solutions Limited | Information & communication | 2012 |
| Accommodating Ltd | Real estate | 2021 |
| Accommodating R2R Ltd | Real estate | 2024 |
| Ace Guitar Academy Ltd | Arts & recreation | 2014 |
| Ace Pet Services Ltd | Agriculture & fishing | 2025 |
| Aces High Aviation Gallery Limited | Arts & recreation | 2003 |
| Aces High Fine Art Limited | Arts & recreation | 2003 |
| Achilles Group Investments Limited | Financial services | 2006 |
| Achilles Group Limited | Financial services | 2000 |
| Achilles Holdco Limited | Financial services | 2008 |
| Acme Electrical Services Ltd | Construction | 2020 |
| ACR Agency Ltd | Arts & recreation | 2022 |
| Acreedo Tattoos Limited | Other services | 2012 |
| Across the Pond Fitness Limited | Arts & recreation | 2020 |
| Action for Carers (Oxfordshire) Ltd | Information & communication | 2012 |
| Action Mirror Productions Ltd. | Information & communication | 2014 |
| Active Driveway & Patio Abingdon Limited | Administrative & support | 2020 |
| Active Needle Technology Ltd | Professional & scientific | 2016 |
| Actus Finance Ltd | Professional & scientific | 2026 |
| Acumen IBC Ltd | Professional & scientific | 2016 |
| Acumen Property Management Ltd | Real estate | 2021 |
| Acute Carpentry Limited | Construction | 2010 |
| ADA Action Ltd | Other services | 2022 |
| ADA Ascot Limited | Hospitality | 2024 |
| Adacca Ltd | Professional & scientific | 2011 |
| Adam Farragher Racing Ltd | Arts & recreation | 2024 |
| Adams Habermehl Ltd | Professional & scientific | 2014 |
| Adaptimmune Limited | Professional & scientific | 2007 |
| Adaptimmune Therapeutics PLC | Professional & scientific | 2014 |
| Adcon (Contracting) Ltd | Construction | 2013 |
| ADD Clarity Ltd | Information & communication | 2019 |
| Addictive Tracks Limited | Information & communication | 2014 |
| Adept Enterprises Limited | Professional & scientific | 2012 |
| Adhectic Limited | Wholesale & retail | 1959 |
| Adrian COX Ltd | Extraterritorial | 2015 |
| ADT Mechanical Ltd | Construction | 2025 |
| Advanced Coffee Equipment & Supplies Limited | Administrative & support | 2002 |
| Advanced Holistic Care Limited | Health & social care | 2024 |
| Advanced Impactor Limited | Arts & recreation | 2025 |
| Advanced Safety Response Ltd. | Professional & scientific | 2014 |
| Advanced Watercoolers Ltd | Administrative & support | 2018 |
| Advancedeed Property Management Limited | Real estate | 1987 |
| Advantage Racing Club Ltd | Arts & recreation | 2022 |
| Advocate Care Services Ltd | Health & social care | 2015 |
| AED Electrical Services Limited | Construction | 2010 |
| Aegis (UK) Group Ltd | Extraterritorial | 2012 |
| Aesthetics by Angela Ltd | Health & social care | 2021 |
| Aesthetics by Clouds Limited | Other services | 2025 |
| AFB Property Investments Limited | Construction | 2014 |
| Aferry Group Limited | Professional & scientific | 2017 |
| Affordable Lofts (Oxford) Ltd | Construction | 2015 |
| African Caribbean Autism Family Support Group CIC | Public administration | 2025 |
| After Dark Investment Limited | Professional & scientific | 2001 |
| Aftersales Equipment Limited | Wholesale & retail | 2021 |
| Against Breast Cancer (Trading) Limited | Wholesale & retail | 1997 |
| Against Breast Cancer Holdings Limited | Financial services | 2024 |
| Against Breast Cancer Limited | Administrative & support | 2007 |
| AGE UK Oxfordshire | Administrative & support | 2001 |
| AGE UK Oxfordshire Trading Ltd | Information & communication | 2006 |
| Agenda Marketing PLC | | 1992 |
| Ager Consulting Limited | Agriculture & fishing | 2014 |
| AGF Services Limited | Construction | 2021 |
| Aglow Records Limited | Information & communication | 2021 |
| AGM Plumbing and Heating Limited | Construction | 2013 |
| Agma Capital Limited | Real estate | 2025 |
| AHY Medya Ltd | Wholesale & retail | 2026 |
| Aibc Accounting Ltd | Professional & scientific | 2019 |
| AIG Vehicles Ltd | Wholesale & retail | 2019 |
| AIM Optics Limited | Health & social care | 2022 |
| Air Pilot Publishing Limited | Information & communication | 2003 |
| Aircharge Ltd | Information & communication | 2013 |