| A to Z Investments Limited | Wholesale & retail | 2009 |
| A Ubhi & Co Limited | Information & communication | 2025 |
| A W Mellor Ltd | Financial services | 2025 |
| A Ward Plumbing and Heating Ltd | Construction | 2019 |
| A Wray Electrical Limited | Construction | 2016 |
| A Wray Properties Limited | Real estate | 2024 |
| A&B Accounting Services Ltd | Professional & scientific | 2025 |
| A&D Motor Care Ltd | Wholesale & retail | 2021 |
| A&E Deluxe Cleaning Ltd | Administrative & support | 2024 |
| A&F Rentals Limited | Real estate | 2017 |
| A&G Greenland Ltd | Real estate | 2022 |
| A&H Properties (York) Ltd | Real estate | 2016 |
| A&J Consultancy Ltd | Extraterritorial | 2002 |
| A&J Property Solutions Ltd | Real estate | 2018 |
| A&S Property York Limited | Real estate | 2022 |
| A&U Bricks Ltd | Real estate | 2026 |
| A-Team Solar Ltd | Manufacturing | 2022 |
| A-Techs Wind Limited | Professional & scientific | 2023 |
| A-Z Property Leasing Limited | Real estate | 2022 |
| A-Z Treasury Services Ltd | Financial services | 2014 |
| A. & G. Layton & Sons Limited | Agriculture & fishing | 1974 |
| A. Dukes Builders Limited | Construction | 2002 |
| A. M. Vision Limited | Wholesale & retail | 2002 |
| A. Monk & Company Developments (S.W.) Limited | Professional & scientific | 1967 |
| A. Rhodes (Haulage) Limited | Transport & logistics | 1979 |
| A. Thorne & Co. Limited | Wholesale & retail | 1971 |
| A. Watkinson Limited | Wholesale & retail | 2024 |
| A.E.A. Prowting Limited | Extraterritorial | 1961 |
| A.E.M.T.Limited | Other services | 1945 |
| A.G. Production Machines Limited | Manufacturing | 1978 |
| A.I. Talent Ltd | Information & communication | 2003 |
| A.I.M.S.Construction Limited | Construction | 1972 |
| A.J.G Property Holdings Ltd | Real estate | 2024 |
| A.K. Housing Investments Ltd | Real estate | 2016 |
| A.M.C. Recordings Limited | Information & communication | 2010 |
| A.N.I. Electrical Yorkshire Ltd. | Construction | 2011 |
| A.N.R. Associates Limited | Information & communication | 1994 |
| A.P. Claxton Ltd | Wholesale & retail | 2011 |
| A.R.T. Business Consulting Limited | Professional & scientific | 2001 |
| A.W. Eadie Limited | Construction | 2008 |
| A1 Businesses Ltd | Real estate | 2018 |
| A1 Holiday Lets Limited | Real estate | 2019 |
| A1 Idsystems Limited | Administrative & support | 2002 |
| A1 Insurance Services Limited | Financial services | 1988 |
| A1 Moto Services Limited | Wholesale & retail | 2009 |
| A1 Northern Windscreens Limited | Wholesale & retail | 2008 |
| A1 Stocktakers Ltd | Administrative & support | 2022 |
| A1 Wetherby Car Storage Ltd. | Transport & logistics | 2015 |
| A19 Buisness Park Ltd | Transport & logistics | 2025 |
| A19 Consultancy Limited | Professional & scientific | 2022 |
| A19 Fire Wood Ltd | Agriculture & fishing | 2026 |
| A19 Garden Machinery Ltd | Manufacturing | 2012 |
| A2Z Electrical (York) Ltd | Manufacturing | 2025 |
| A2Z Maintenance Solutions Ltd | Construction | 2023 |
| A3 Consulting Limited | Construction | 2021 |
| A64 Van Sales Ltd | Wholesale & retail | 2023 |
| A64BAR Limited | Hospitality | 2019 |
| AAA Freight Ltd | Transport & logistics | 2024 |
| AAA Lettings Limited | Real estate | 2008 |
| AAA Road Freight Ltd | Transport & logistics | 2023 |
| AAI Selby Fire Limited | Extraterritorial | 2022 |
| Aardvark Language Services Ltd | Professional & scientific | 2011 |
| Aardvic Holdings Ltd | Financial services | 2021 |
| Aariz Mahimi Capital Limited | Real estate | 2025 |
| Aaron Bradley Ltd | Real estate | 2024 |
| Aarons Auto Services York Ltd | Wholesale & retail | 2025 |
| AAT Bowman Limited | Agriculture & fishing | 2019 |
| Aawatson Project Consulting Limited | Professional & scientific | 2011 |
| Aaztec Holdings Limited | Financial services | 2025 |
| AB Alpha Developers Limited | Construction | 2016 |
| AB Deep Sea Services Limited | Professional & scientific | 2017 |
| AB Electrical Wholesalers Holdings Limited | Financial services | 2025 |
| AB Property Consulting Ltd | Real estate | 2018 |
| AB1986 Limited | Construction | 2023 |
| Abacus Removals (York) Limited | Transport & logistics | 2004 |
| Aban Legal Consultancy Limited | Professional & scientific | 2022 |
| Abbey Court Management Co. Limited | Households | 1982 |
| Abbey Green (Amesbury) Management Company Limited | Households | 2015 |
| Abbey Guest House York Limited | Hospitality | 2025 |
| Abbey Signs & Engravers Limited | Manufacturing | 2003 |
| Abbey Veterinary Centres Limited | Professional & scientific | 2008 |
| Abbeydale Properties Limited | Construction | 1968 |
| Abbeyfield York Home Care Limited | Health & social care | 2008 |
| Abbeyfield York Society Limited(The) | Real estate | 1962 |
| Abbeylands Developments Limited | Real estate | 2020 |
| Abbeyserve Limited | Professional & scientific | 2015 |
| Abbeyview (Howden) Management Company Limited | Real estate | 2006 |
| Abbot Walk (Chatteris) Residents Management Company Limited | Households | 2022 |
| Abbots Mews Apartments Ltd | Real estate | 2024 |
| Abbots Mews Hotels Limited | Extraterritorial | 1984 |
| Abbotscross Management Company Limited | Households | 2010 |
| Abbotsford Gardens Limited | Households | 1990 |
| Abbotsham Park (Bideford) Management Company Limited | Households | 2024 |
| Abbotts Mews Management Company York Ltd | Households | 2020 |
| ABC Physiotherapy Ltd | Health & social care | 2017 |
| ABC Sanders Limited | Professional & scientific | 2013 |
| Abc-Sports-Clubs Ltd | Hospitality | 2022 |
| Abc-Tennis-Uk Limited | Arts & recreation | 2019 |
| ABD Networks LLP | | 2007 |
| Abdl Property Management Solutions Limited | Real estate | 2023 |