| ASI Controls Ltd | Professional & scientific | 2017 |
| Asia Foods (Huddersfield) Ltd | Wholesale & retail | 2026 |
| Asjad Medical Services Limited | Health & social care | 2009 |
| Asjbl Limited | Wholesale & retail | 2025 |
| ASK Benson Ltd | Transport & logistics | 2026 |
| ASK Consultancy Yorkshire Ltd | Professional & scientific | 2022 |
| ASK for the Moon Limited | Arts & recreation | 2006 |
| ASK Management Ltd | Professional & scientific | 2020 |
| ASK4CARE Ltd | Other services | 2017 |
| Aska Wholesale Foods Ltd | Wholesale & retail | 2025 |
| Askco Shopfitters Limited | Construction | 2020 |
| Askrj Ltd | Wholesale & retail | 2022 |
| Aslam Pharmaceuticals Ltd | Wholesale & retail | 2023 |
| Asma Akram Ltd | Wholesale & retail | 2024 |
| Asmaah Trading Limited | Wholesale & retail | 2021 |
| Asoss Civil Engineering Limited | Construction | 2025 |
| Aspect Beds Limited | Wholesale & retail | 2024 |
| Aspect Roofing & Upvc Ltd | Construction | 2020 |
| Aspen Hotels Limited | Hospitality | 2013 |
| Aspen House Trading Ltd | Hospitality | 2026 |
| Aspietravels Ltd | Administrative & support | 2023 |
| Aspinall Enforcement Ltd | Administrative & support | 2015 |
| Aspiration (Huddersfield) Limited | Wholesale & retail | 2006 |
| Aspire 2 Excellence Limited | Professional & scientific | 2013 |
| Aspire Builders Limited | Construction | 2025 |
| Aspire Co-Operative Learning Trust | Education | 2011 |
| Aspire Commercial Ltd | Real estate | 2024 |
| Aspire Tutoring Ltd | Education | 2021 |
| Aspire Xpress Ltd | Wholesale & retail | 2025 |
| Aspley Heights Management Company Limited | Households | 2006 |
| Aspley Projects Limited | Real estate | 2017 |
| Aspley Services Limited | Manufacturing | 2011 |
| Aspley Silver Limited | Professional & scientific | 2014 |
| Asquare IT Consulting Ltd | Information & communication | 2022 |
| Asquith Green International Limited | Administrative & support | 2024 |
| Asra Trading Ltd | Wholesale & retail | 2020 |
| Asrk Limited | Health & social care | 2012 |
| Assemble Projects Limited | Construction | 2004 |
| Associated CD Limited | Other services | 2003 |
| Association for Environment Conscious Building | Other services | 2005 |
| Association of Independent Creative Education | Other services | 1997 |
| Assured Pro Roofing (Yorkshire) Ltd | Construction | 2026 |
| Assut UK Limited | Health & social care | 2005 |
| AST UK Project Ltd | Construction | 2024 |
| Aster Medical Services Limited | Health & social care | 2018 |
| Aston Legal Ltd | Financial services | 2009 |
| Astonishing Events Ltd | Arts & recreation | 2022 |
| Astonstyle Developments Limited | Construction | 2018 |
| Astonstyle Properties Limited | Real estate | 2020 |
| Astonstyle Property Developments Ltd | Construction | 2023 |
| Astris Consulting Ltd | Professional & scientific | 2023 |
| Astrondo Ltd | Information & communication | 2019 |
| Asturlab Ltd | Administrative & support | 2024 |
| Astute Transformations Limited | Professional & scientific | 2018 |
| Asymphonyproperties Limited | Real estate | 2025 |
| Asyn International Ltd | Wholesale & retail | 2022 |
| AT90STORE1 Ltd | Wholesale & retail | 2025 |
| Ataar UK Ltd | Information & communication | 2026 |
| ATD Transport Ltd | Transport & logistics | 2025 |
| Athar Travels Ltd | Transport & logistics | 2025 |
| Athena Creative Media Ltd | Information & communication | 2022 |
| Athlete Support Guide Limited | Information & communication | 2024 |
| Athlthq CIC | Education | 2025 |
| Athltiq Ltd | Arts & recreation | 2025 |
| Athreeh Traders Ltd | Wholesale & retail | 2023 |
| Atif Optical Limited | Wholesale & retail | 2019 |
| Atiq UR Rehman Ltd | Wholesale & retail | 2025 |
| Atkinson Family Investment Company Unlimited | Financial services | 2019 |
| Atkinson Financial Research and Policy Ltd | Administrative & support | 2021 |
| Atkinson Property Investments Limited | Real estate | 2019 |
| ATL Consultancy Ltd | Professional & scientific | 2021 |
| Atlantis Homes and Lettings Limited | Real estate | 2026 |
| Atlantis Pizza (Holmfirth) Ltd | Hospitality | 2019 |
| Atlas Display (D.H.B.) Limited | Administrative & support | 1995 |
| Atlas Display Holdings Limited | Financial services | 2019 |
| Atlas Process Equipment Limited | Professional & scientific | 2017 |
| Atlas Rail Components Limited | Professional & scientific | 1990 |
| Atlas Residential Limited | Real estate | 2026 |
| Atmar Estates Ltd | Real estate | 2025 |
| Atmar Ltd | Wholesale & retail | 2026 |
| Atraxa Consulting Limited | Professional & scientific | 2005 |
| Atraxa Investments Limited | Professional & scientific | 2007 |
| Attain Outdoor Community CIC | Education | 2025 |
| Auctus Investments Limited | Financial services | 2021 |
| Audin Homecare Limited | Other services | 2001 |
| Audio Haven Rentals Ltd | Administrative & support | 2025 |
| Audio Stew Ltd | Information & communication | 2023 |
| Audrey Spencer School of Theatre Dance Limited | Arts & recreation | 2014 |
| AUG Data Limited | Information & communication | 2021 |
| Aunate Ltd | Manufacturing | 2024 |
| Aura Print (UK) Ltd | Manufacturing | 2007 |
| Aura Wellbeing Ltd | Health & social care | 2025 |
| Auricle Solutions Ltd | Health & social care | 2022 |
| Aurora Cosmetics UK Ltd | Wholesale & retail | 2025 |
| Aurora Empire Ltd | Wholesale & retail | 2020 |
| Aurora Media Ltd | Information & communication | 2025 |
| Aurora Trading Ltd | Wholesale & retail | 2025 |
| Austar UK Limited | Manufacturing | 2020 |
| Authentic Marketing Limited | Professional & scientific | 2023 |
| Auto Ace Yorkshire Ltd | Professional & scientific | 2022 |