| AFV Property Ltd | Real estate | 2017 |
| AG Classic Car Tuning Ltd | Wholesale & retail | 2024 |
| AG Construction & Developments Ltd | Construction | 2018 |
| AG Travel & Leisure Limited | Health & social care | 2012 |
| Agacare York Ltd | Administrative & support | 2024 |
| Agape Medical Limited | Health & social care | 2015 |
| Agapy Limited | Hospitality | 2024 |
| Agathon Gaming Limited | Wholesale & retail | 2024 |
| AGE UK York | Information & communication | 2006 |
| AGE UK York Enterprises Ltd | Financial services | 2003 |
| AGENCY51 Limited | Information & communication | 2005 |
| Agencyserve Limited | Extraterritorial | 2023 |
| Agglestone Limited | Real estate | 2020 |
| AGH Electrical Solutions Limited | Construction | 2026 |
| AGH Engineering Ltd | Professional & scientific | 2006 |
| AGH Systems Ltd | Information & communication | 2022 |
| Agile Business Partners Ltd | Professional & scientific | 2023 |
| Agile Interior Products Limited | Wholesale & retail | 2008 |
| Agile Software Management Limited | Information & communication | 2012 |
| Agile Strategies Ltd | Information & communication | 2025 |
| Agile Think Ltd | Information & communication | 2009 |
| AGK Print & Design Limited | Arts & recreation | 2017 |
| AGK Property Rentals Limited | Real estate | 2025 |
| Agnew Construction Ltd | Construction | 2021 |
| Agora Advisories Ltd | Professional & scientific | 2026 |
| Agosto (York) Limited | Hospitality | 2022 |
| AGP York Ltd | Real estate | 2023 |
| Agramkow UK Ltd | Wholesale & retail | 2023 |
| Agri Sales Limited | Wholesale & retail | 2013 |
| Agri Sign Ltd | Manufacturing | 2022 |
| Agri Silo Ltd | Wholesale & retail | 2022 |
| Agri-Epi Centre Limited | Agriculture & fishing | 2015 |
| Agri-Plant Sales Limited | Wholesale & retail | 2025 |
| Agricultural & Engineering Services Limited | Professional & scientific | 2009 |
| Agrifood X Limited | Professional & scientific | 2019 |
| Agriguard Services Ltd | Administrative & support | 2024 |
| Agripest Limited | Agriculture & fishing | 2019 |
| Agripetuk Ltd | Wholesale & retail | 2025 |
| Agrisk Ltd | Construction | 2021 |
| Agrivation Limited | Professional & scientific | 2014 |
| Agriyork 400 Limited | Wholesale & retail | 1987 |
| Agrosense Biotechnologies Ltd | Information & communication | 2026 |
| Agsi Ltd | Professional & scientific | 2020 |
| Agusta Park Yeovil Management Company Limited | Households | 2015 |
| AH Marketing Limited | Professional & scientific | 2017 |
| AH Pinkney Ltd | Professional & scientific | 2017 |
| AH4 Ltd | Professional & scientific | 2018 |
| Ahcoding Ltd | Health & social care | 2018 |
| Ahead Limited | Professional & scientific | 1992 |
| Ahmanta Limited | Health & social care | 2008 |
| Ahmc Enterprises Limited | Administrative & support | 2013 |
| Ahsc Limited | Real estate | 2018 |
| AI BOT Limited | Information & communication | 2018 |
| AI Education Group Ltd | Education | 2025 |
| AI in Schools Ltd | Education | 2024 |
| AI Innovations Group Limited | Information & communication | 2023 |
| AI Marketing Solutions Ltd | Professional & scientific | 2023 |
| AI Trading Software Ltd | Information & communication | 2025 |
| Aicd Ltd | Professional & scientific | 2026 |
| Aidmeuk Ltd | Health & social care | 2023 |
| AIJ Properties Ltd | Real estate | 2016 |
| Aiken Holdings Ltd | Real estate | 2026 |
| Aiken Properties York Ltd | Real estate | 2026 |
| Aiken Property Services Ltd | Real estate | 2024 |
| Aimmune Nestle Health Science UK R&D Limited | Professional & scientific | 2021 |
| Aimmune Therapeutics UK Limited | Manufacturing | 2015 |
| Ainsty Ales Brewery Limited | Manufacturing | 2023 |
| Ainsty Ales Limited | Manufacturing | 2013 |
| Ainsty Development Consulting Limited | Professional & scientific | 2018 |
| Ainsty Nominees Limited | Professional & scientific | 1962 |
| Ainsty Risk Consulting Limited | Professional & scientific | 2010 |
| Ainsty Timber Marketing Limited | Agriculture & fishing | 1979 |
| Ainsworth & Martin (Preston) Limited | Information & communication | 1981 |
| Ainsworth Consulting Group Ltd | Professional & scientific | 2003 |
| Ainsworth Electrical Services Ltd | Construction | 2021 |
| Aintree Services Ltd | Health & social care | 2021 |
| Aion Accounting Technologies Ltd | Professional & scientific | 2024 |
| Air Residential Ltd | Real estate | 2024 |
| Air Supply Limited | Wholesale & retail | 2002 |
| Aire Street and ST Johns Street Buildings Management Company Limited | Real estate | 2015 |
| Aire View Gardens Management Company Limited | Households | 1997 |
| Airedale Amusements Ltd | Arts & recreation | 2023 |
| Airevalley Tree Consultancy Ltd | Professional & scientific | 2025 |
| Airfield Concrete Ltd | Manufacturing | 2022 |
| Airfield Nurseries Ltd | Wholesale & retail | 2019 |
| Airgse Ltd | Extraterritorial | 2016 |
| Airheads Ltd | Manufacturing | 2026 |
| Airport Lettings Stansted Limited | Real estate | 2003 |
| Airside Services (Yorks) Ltd | Manufacturing | 2012 |
| Airspeed (York) Limited | Arts & recreation | 2013 |
| Airstore Renewables Ltd | Wholesale & retail | 2023 |
| Airtight Consultancy Limited | Professional & scientific | 2003 |
| Aitnik Consultancy Limited | Professional & scientific | 2024 |
| AJ Engineering Design Limited | Professional & scientific | 2015 |
| AJ Gibson Limited | Professional & scientific | 2012 |
| AJ Premier Properties Ltd | Real estate | 2025 |
| AJ Staycation Limited | Real estate | 2023 |
| AJB Travel Ltd | Administrative & support | 2024 |
| AJC Law Solicitors Limited | Professional & scientific | 2010 |
| AJD Music Production Limited | Information & communication | 1999 |