| Albany Care Property Management Ltd | Other services | 2016 |
| Albero Limone Limited | Administrative & support | 2010 |
| Alchemy Professions Limited | Professional & scientific | 2022 |
| Alcyone Healthcare North East Ltd | Health & social care | 2010 |
| Aldap Ltd | Professional & scientific | 2021 |
| Alex Jacob Limited | Real estate | 2013 |
| Alex Laine Limited | Wholesale & retail | 2022 |
| Alexa's Studio Ltd | Other services | 2024 |
| ALI Pyner Nutrition Limited | Health & social care | 2024 |
| Alice Chilton in Home Care Services Ltd | Health & social care | 2014 |
| ALL Sorts of Bargains Ltd | Wholesale & retail | 2025 |
| ALL Star Recruitment Ltd | Other services | 2025 |
| Allresin Limited | Construction | 2024 |
| Almond Press Ltd | Information & communication | 2025 |
| Alomsi Limited | Hospitality | 2024 |
| Alpha A2Z Local Limited | Extraterritorial | 2024 |
| Alpha Card Compact Media Limited | Manufacturing | 2013 |
| Alps Construction Services Limited | Construction | 2021 |
| Alta Luci Hair Studio Limited | Other services | 2010 |
| Alterego (UK) Limited | Administrative & support | 2003 |
| Altitude Property Services Ltd | Hospitality | 2022 |
| Altman Information Management Limited | Information & communication | 2012 |
| Alvaros Limited | Households | 1984 |
| Alwyn Kotze Ltd | Information & communication | 2021 |
| Alwys Ltd | Information & communication | 2026 |
| AM Fleet Maintenance Ltd | Manufacturing | 2026 |
| AM PM Mart Ltd | Wholesale & retail | 2015 |
| Amber Neon Ltd | Manufacturing | 2020 |
| Ambercp Ltd | Professional & scientific | 2018 |
| Ambiflow Limited | Construction | 2017 |
| AMC Design Limited | Professional & scientific | 2017 |
| Amco Venue 163 Management Company Limited | Real estate | 2011 |
| American Traveller Europe Ltd | Wholesale & retail | 2024 |
| Ameuri Limited | Financial services | 2012 |
| Amplekind Ltd | Real estate | 2020 |
| Anamica Limited | Professional & scientific | 2021 |
| Anchorstone Holiday Lets Ltd | Real estate | 2025 |
| Anchorstone Properties Ltd | Real estate | 2025 |
| AND Theory Ltd | Education | 2022 |
| Andrew Hatfield Associates Limited | Health & social care | 2012 |
| Andrew James Lovatt Ltd | Extraterritorial | 2024 |
| Andrew Millar (Holdings) Ltd | Financial services | 2011 |
| Andrew Millar Ltd | Information & communication | 2007 |
| Andrews Access Limited | Wholesale & retail | 2023 |
| Andrews Transport Ltd | Transport & logistics | 2017 |
| Angels Hair Beauty Massage Limited | Other services | 2019 |
| Animo PR Limited | Professional & scientific | 2006 |
| Anita Morris Ltd | Professional & scientific | 2025 |
| Anlaby Holdings Ltd | Financial services | 2024 |
| Anlaby Office Cleaning Services Limited | Administrative & support | 2001 |
| Anlaby Window Cleaning Services Limited | Administrative & support | 2001 |
| Anna Beth Photography Ltd | Professional & scientific | 2026 |
| Anthousai Limited | Financial services | 2024 |
| Antmid Limited | Hospitality | 2020 |
| Antony Ransom Independent Financial Adviser Limited | Financial services | 2004 |
| Anver Computers Limited | Information & communication | 1996 |
| Anvidar Ltd | Real estate | 2025 |
| Appletrees Advisory Ltd | Professional & scientific | 2017 |
| April's View Management Ltd | Households | 2023 |
| Aptchoice Ltd | Wholesale & retail | 2020 |
| Arcade Kitchens & Bedrooms Ltd | Wholesale & retail | 2022 |
| Archacre Property Management Limited | Real estate | 1984 |
| Architects Build Limited | Professional & scientific | 2022 |
| Ardorum Limited | Information & communication | 2014 |
| Argentum Services Ltd | Professional & scientific | 2018 |
| Aristone Holdings Limited | Real estate | 2025 |
| Arlo Coffee House Ltd | Hospitality | 2020 |
| Armoury in Action Limited | Information & communication | 2020 |
| Army Fit Ltd | Arts & recreation | 2010 |
| Arnold Property Holdings (North) Ltd | Real estate | 2021 |
| Art Deco and More Limited | Wholesale & retail | 2022 |
| Artisan Retail (Holdings) Limited | Financial services | 2023 |
| Artisan Retail (Leeds) Limited | Hospitality | 2018 |
| Arva Property Ltd | Real estate | 2025 |
| Ascent Apartments Ltd | Real estate | 2024 |
| Ascent People Development Ltd | Administrative & support | 2015 |
| Ascentis Accountants LLP | | 2013 |
| Asco 205 Limited | Financial services | 2005 |
| Ashbrook Management Company Limited | Households | 2016 |
| Ashby Knight Limited | Education | 2019 |
| Ashiana Ilkley Limited | Hospitality | 2020 |
| Ashlands Properties Limited | Real estate | 2016 |
| Ashlyn Properties Limited | Real estate | 1999 |
| Aspiring Sports Ltd | Arts & recreation | 2025 |
| Associated Transport Services Limited | Professional & scientific | 2007 |
| Astonway Developments Limited | Professional & scientific | 1990 |
| Astralis Investments Limited | Real estate | 2025 |
| Astralis Sourcing Limited | Real estate | 2025 |
| Atelier Performance Ltd | Professional & scientific | 2026 |
| Atkinson Fine Arts Ltd | Arts & recreation | 2022 |
| Audio Division Ltd | Manufacturing | 2017 |
| Audsley Magpie | Professional & scientific | 2016 |
| Augment Equity Ltd | Administrative & support | 2018 |
| Augusta Family Investments | Financial services | 2026 |
| Aurelle Group Ltd | Wholesale & retail | 2026 |
| Auriole Ltd | Other services | 2025 |
| Auto Assist (N.E) Ltd | Other services | 2019 |
| Automotive Payroll Systems Limited | Other services | 2019 |
| Autonomous Avatar Ltd | Information & communication | 2025 |
| Autotubetech LLP | | 2011 |