| Alpha Anaesthetic Services Limited | Health & social care | 2021 |
| Alpha Business Solutions Ltd | Information & communication | 2018 |
| Alpha Cloud Limited | Wholesale & retail | 2021 |
| Alpha Facilities Management Solutions Ltd | Administrative & support | 2026 |
| Alpha Garage Hull Limited | Wholesale & retail | 2021 |
| Alpha IT Services Limited | Information & communication | 2002 |
| Alpha Key Innovations Limited | Real estate | 2025 |
| Alpha Motor Care Ltd | Manufacturing | 2014 |
| Alpha One Solutions Limited | Information & communication | 2024 |
| Alpha Skinmetry Longevity Clinic Limited | Health & social care | 2025 |
| Alpha Taverns Ltd | Hospitality | 2026 |
| Alpha Tiling Contractors Ltd. | Construction | 2016 |
| Alphafoxtrot Invest Limited | Real estate | 2024 |
| Alphard Group UK Ltd | Wholesale & retail | 2020 |
| Alphase 2024 Limited | Wholesale & retail | 2024 |
| Alphase UK Limited | Wholesale & retail | 2009 |
| Alphyra Audio Visual Limited | Professional & scientific | 2016 |
| Alphys Limited | Health & social care | 2023 |
| Alpi Properties Limited | Real estate | 2024 |
| Alpine HC Holdings Limited | Financial services | 2020 |
| Alpine HC Limited | Other services | 2007 |
| ALS (Hull) Ltd | Manufacturing | 2024 |
| Alsa PH Ltd | Professional & scientific | 2018 |
| Alsefrany Ltd | Wholesale & retail | 2025 |
| ALT Properties Limited | Real estate | 2001 |
| Altaib Ltd | Wholesale & retail | 2024 |
| Alterperks Limited | Information & communication | 2025 |
| Altnotify Ltd | Information & communication | 2014 |
| Altraconnect Ltd | Information & communication | 2025 |
| Aluform (UK) Ltd | Manufacturing | 2006 |
| Alyn Construct Ltd | Construction | 2023 |
| AM Enforcement Yorkshire Ltd | Administrative & support | 2019 |
| AM Polish School Ltd | Education | 2023 |
| AM Property Hull Ltd | Real estate | 2026 |
| AM Racing Limited | Arts & recreation | 2021 |
| AM79 Ltd | Professional & scientific | 2021 |
| AMA Fasteners Limited | Wholesale & retail | 2013 |
| AMA FIX Ltd | Construction | 2024 |
| Amac Global Ltd | Wholesale & retail | 2025 |
| Amadena Ltd | Other services | 2018 |
| Amaku Limited | Wholesale & retail | 2019 |
| Amani (Hull) Limited | Hospitality | 2011 |
| Amani Property Ltd | Real estate | 2026 |
| Amani S Kitchen Limited | Hospitality | 2024 |
| Amanita Wild Club Limited | Education | 2024 |
| Amapled Properties Limited | Real estate | 1971 |
| Amariei Properties Ltd | Real estate | 2023 |
| Amazing Grace & Brothers Ltd | Wholesale & retail | 2026 |
| Amazon Aluminium Limited | Construction | 2015 |
| Amazon Window Systems Ltd | Construction | 2009 |
| AMB Collective Limited | Professional & scientific | 2025 |
| AMB Parcels Limited | Transport & logistics | 2024 |
| Amba Construction Ltd | Construction | 2014 |
| Amber Cafe Hull Ltd | Hospitality | 2024 |
| Amber Hotel Property Limited | Hospitality | 2025 |
| Amber Joinery Ltd | Construction | 2020 |
| Amber Powder Coatings Ltd | Manufacturing | 2013 |
| Amber Travel (Hull) Ltd | Professional & scientific | 2012 |
| Amber's Bar Ltd | Hospitality | 2025 |
| Ambitious Advertising Ltd | Information & communication | 2026 |
| Ambledon Civils Ltd | Construction | 2022 |
| Ambocare Ltd | Health & social care | 2022 |
| AMD Glass Ltd | Wholesale & retail | 2024 |
| Amelia (Hull) Limited | Hospitality | 2017 |
| American Standard (U.K.) Co. | Financial services | 1977 |
| Amethyst Hardware Store Limited | Wholesale & retail | 2024 |
| AMG Rental Properties Ltd | Real estate | 2025 |
| AMH Group Ltd | Construction | 2025 |
| AMH Hire Ltd | Construction | 2018 |
| Amht Financial Solutions Limited | Financial services | 2015 |
| Amici Affair Limited | Hospitality | 2018 |
| Amiprime Ltd | Wholesale & retail | 2026 |
| AMJ Group Holdings Ltd | Financial services | 2020 |
| AMJ Group Property Ltd | Real estate | 2020 |
| AMJ Maintenance Ltd | Construction | 2013 |
| AMJ Modular Ltd | Construction | 2016 |
| Amjo Electrical and Fire Ltd | Construction | 2021 |
| Amjo Property Ltd | Real estate | 2017 |
| Amll Properties Ltd | Real estate | 2024 |
| Amma Pop'Dom Limited | Hospitality | 2025 |
| Ammok Ltd | Transport & logistics | 2018 |
| Amnati Limited | Wholesale & retail | 2025 |
| AMO Steel Detailing Limited | Professional & scientific | 2016 |
| Amor Express International Ltd | Transport & logistics | 2025 |
| Amorim & Sanchez Limited | Hospitality | 2024 |
| Ampera EV Ltd | Wholesale & retail | 2025 |
| Ampg Surveying Services Ltd | Professional & scientific | 2026 |
| Amro Property Services Ltd | Households | 2025 |
| AMS Deal Shop Ltd | Wholesale & retail | 2023 |
| AMS Electrical (Yorkshire) Ltd | Construction | 2009 |
| Amses Ltd | Wholesale & retail | 2013 |
| AMY Flowers Ltd | Wholesale & retail | 2025 |
| AMY Gray Wealth Management Limited | Professional & scientific | 2021 |
| AMY Johnson Arts Trust | Arts & recreation | 2014 |
| AMY L Williams Ltd | Transport & logistics | 2022 |
| AMY Limited | Other services | 2026 |
| AMY Nail Spa Ltd | Other services | 2018 |
| Amykas Ltd | Wholesale & retail | 2022 |
| Amykas Management Limited | Construction | 2026 |
| AN Motor Care Limited | Wholesale & retail | 2025 |