| Armstrong Engineering & Design Ltd | Professional & scientific | 2017 |
| Armstrong Optical Services Ltd | Professional & scientific | 2024 |
| Armstrong Pickering LLP | | 2026 |
| Armstrong Plumbing and Heating York Ltd | Construction | 2020 |
| Armstrong Vets Limited | Professional & scientific | 2013 |
| Armstrong-Brown Limited | Hospitality | 2017 |
| Arncliffe Mews (York) Maintenance Limited | Households | 1974 |
| Arnold Productions Ltd | Arts & recreation | 2026 |
| Arnold Way (Grove) Management Company Limited | Households | 2021 |
| Arnold Way NO. 2 (Grove) Management Company Limited | Households | 2021 |
| Arnold Way NO. 3 (Grove) Management Company Limited | Households | 2022 |
| Arnott Estates Ltd | Real estate | 2017 |
| Aroks Investments Limited | Wholesale & retail | 2025 |
| Aroma 2 Limited | Hospitality | 2018 |
| Aroma Professional Catering Limited | Hospitality | 2018 |
| Arooh Ltd | Real estate | 2023 |
| Around OUR GAF (Dinnington) Ltd | Hospitality | 2024 |
| Around OUR GAF (Stag) Ltd | Hospitality | 2025 |
| Around OUR GAF Ltd | Hospitality | 2020 |
| Around the Bend (UK) Limited | Education | 2006 |
| ARR & JAY Ltd | Manufacturing | 2013 |
| Arras Holdings Limited | Agriculture & fishing | 2017 |
| Arras Restaurants Limited | Hospitality | 2016 |
| Arriva Trains Northern Limited | Transport & logistics | 1995 |
| Art & Soul Hub Ltd | Wholesale & retail | 2020 |
| Art Attack Studio Ltd | Arts & recreation | 2024 |
| Art Candles UK Ltd | Wholesale & retail | 2012 |
| Art From the Start Limited | Wholesale & retail | 2005 |
| Art of Placemaking Ltd | Arts & recreation | 2025 |
| Art of Smart Group Ltd | Construction | 2019 |
| Art Refurbishment Ltd | Transport & logistics | 2016 |
| Arte DE DAR Ltd | Wholesale & retail | 2018 |
| Artek Fabrication Limited | Financial services | 2025 |
| Artemis & Co Ltd | Professional & scientific | 2010 |
| Artfully Yours Ltd | Wholesale & retail | 2025 |
| Arthington Farm Services Ltd | Construction | 1991 |
| Arthur S. Nixon and Company | Extraterritorial | 1945 |
| Artimo Limited | Professional & scientific | 2014 |
| Artisan Precision Machining Limited | Manufacturing | 2006 |
| Artissimo Limited | Health & social care | 2020 |
| Artistic Horizon Ltd | Wholesale & retail | 2019 |
| Artofprotest Ltd | Professional & scientific | 2020 |
| Artork Ltd | Wholesale & retail | 2025 |
| Arts Crafter Ltd | Wholesale & retail | 2019 |
| Arts Education Management Limited | Education | 2019 |
| Arts Management and Consulting Ltd | Professional & scientific | 2020 |
| Arts Photography Limited | Professional & scientific | 2014 |
| Arts Photography Schools Limited | Professional & scientific | 2015 |
| Artych Ltd | Construction | 2022 |
| ARU Property Limited | Real estate | 2014 |
| Arundel Legal Consulting Ltd | Professional & scientific | 2020 |
| Arwn Consulting Ltd | Professional & scientific | 2023 |
| ARX Construction Ltd | Construction | 2021 |
| Arya Design Ltd | Construction | 2018 |
| AS Autotech York Ltd | Wholesale & retail | 2024 |
| AS Bengal Ltd | Hospitality | 2025 |
| AS Pragmatics Ltd | Information & communication | 2025 |
| Asandra | Financial services | 2022 |
| Asbestos Management Consultancy Ltd | Professional & scientific | 2011 |
| Ascend Healthcare Ltd | Health & social care | 2026 |
| Ascham House Management Limited | Households | 2008 |
| Ascia Investments Limited | Financial services | 2019 |
| Asenby Holdings Ltd | Education | 2020 |
| ASH Enviro Ltd | Administrative & support | 2020 |
| ASH Tree Gardens Management Company Limited | Administrative & support | 2014 |
| ASH Tree Veterinary Practice Limited | Extraterritorial | 2014 |
| Ashbrook Associates Limited | Professional & scientific | 2018 |
| Ashcourt (Cumbria) Limited | Mining & quarrying | 2003 |
| Ashcourt (Northumberland) Limited | Mining & quarrying | 1975 |
| Ashcroft Pollard & Co Limited | Professional & scientific | 2013 |
| Ashes 2 Jewellery Ltd | Manufacturing | 2021 |
| Ashfield 2018 Limited | Professional & scientific | 2018 |
| Ashfield Court (York) Limited | Households | 1967 |
| Ashfield Gray Limited | Professional & scientific | 2020 |
| Ashfield House Veterinary Hospital Limited | Professional & scientific | 2004 |
| Ashfield Static & Touring Park Limited | Hospitality | 2015 |
| Ashlands Veterinary Services (2006) Ltd | Extraterritorial | 2006 |
| Ashlea Developments (York) Ltd | Construction | 2019 |
| Ashlea Veterinary Centre Limited | Professional & scientific | 2003 |
| Ashleigh Veterinary Clinic Limited | Extraterritorial | 2010 |
| Ashley Hall Consulting Ltd | Information & communication | 2023 |
| Ashley Park Road Limited | Extraterritorial | 2024 |
| Ashmor Homes Yorkshire Limited | Construction | 2025 |
| Ashoria Worldwide Cargo Ltd | Wholesale & retail | 2025 |
| Ashridge Senior Care Limited | Financial services | 2018 |
| Ashton and Finch Ltd | Wholesale & retail | 2015 |
| Ashton Forensic Psychology Limited | Health & social care | 2019 |
| Ashton Telecommunications Ltd | Information & communication | 2014 |
| Ashtons Property Holdings Limited | Real estate | 2022 |
| Ashtons Residential Sales Limited | Real estate | 2022 |
| Ashtree House (York) Management Company Limited | Extraterritorial | 2008 |
| Ashwold Letting Ltd | Real estate | 2018 |
| Ashwood Developments York Limited | Construction | 2019 |
| Ashwood Parade (Hall Green) Management Company Limited | Households | 2010 |
| Ashworth Place (Phase 2) Management Limited | Households | 2021 |
| Asian Fresh Food York Limited | Wholesale & retail | 2024 |
| ASK Steels Ltd. | Wholesale & retail | 2015 |
| Askham Bryan College Company Ltd | Agriculture & fishing | 1993 |
| Askham Bryan College Enterprises Limited | Hospitality | 1993 |
| Askham Bryan Investments Limited | Financial services | 2022 |