| Altieri Properties Ltd | Real estate | 2025 |
| Altimar Shipping 2017 LLP | | 2017 |
| Altimar Shipping Ltd | Administrative & support | 1999 |
| Altimex Limited | Manufacturing | 1995 |
| Altnagra Investments Limited | Financial services | 2018 |
| Alto Abode Properties Ltd | Real estate | 2025 |
| Altr Hair Ltd | Other services | 2023 |
| Altr Rentals Ltd | Administrative & support | 2023 |
| Altura Property Group Limited | Construction | 2025 |
| Altus Digital Services Limited | Information & communication | 2016 |
| Aluminium Fabrication Limited | Manufacturing | 2025 |
| ALV Healthcare Ltd | Health & social care | 2025 |
| Always Payments Limited | Professional & scientific | 2026 |
| AM Lets Limited | Real estate | 2025 |
| AM MED Limited | Health & social care | 2023 |
| Amakalu Health Promotion Services Ltd | Health & social care | 2025 |
| Amanda Oates: Cultivating Restorative Cultures Ltd | Professional & scientific | 2024 |
| Amarvine Properties Limited | Real estate | 2003 |
| Amasing Projects C.I.C. | Education | 2017 |
| Amasing Services Ltd | Education | 2026 |
| Amaya Advisory Limited | Professional & scientific | 2025 |
| Amazeller Ltd | Administrative & support | 2013 |
| Amazodeals Ltd | Wholesale & retail | 2024 |
| AMB Chester Ltd | Financial services | 2014 |
| Ambassador Business & Computers Limited | Information & communication | 1985 |
| Amber AI Ltd | Information & communication | 2025 |
| Amber BEE CIC | Education | 2022 |
| Amber Furniture Limited | Wholesale & retail | 2006 |
| Amberleigh Shipping Ltd | Professional & scientific | 2014 |
| AMD Trans Ltd | Transport & logistics | 2016 |
| Amelior Consultancy Ltd | Manufacturing | 2019 |
| Amenity Management (Chester) Limited | Real estate | 1987 |
| Amenity Tree Care Limited | Agriculture & fishing | 2001 |
| Amesia 05 Ltd | Hospitality | 2025 |
| AMJ Global Consulting Ltd | Administrative & support | 2022 |
| Ammo (Commercial) Limited | Real estate | 2015 |
| AMO Air CON Ltd | Construction | 2023 |
| Amore Complex Care Ltd | Administrative & support | 2017 |
| Amore Group Ltd | Health & social care | 2020 |
| Amore Social Care Limited | Health & social care | 2017 |
| Ampelora Ltd | Information & communication | 2026 |
| Amphibia Base Ltd | Manufacturing | 2016 |
| Amplifyx Consulting Ltd | Professional & scientific | 2026 |
| AMS (NW) Ltd | Transport & logistics | 2012 |
| AMS Chester Ltd | Financial services | 2014 |
| AMS Resources Ltd | Professional & scientific | 2025 |
| Amulet Consulting Limited | Professional & scientific | 2015 |
| AMW Interim Services Limited | Professional & scientific | 2012 |
| AMY Jennifer Jewellery Limited | Manufacturing | 2024 |
| AMY Lambert Limited | Hospitality | 2024 |
| AMY Padley Aesthetics Limited | Health & social care | 2022 |
| AMY Piercy Hairdressing Ltd | Other services | 2022 |
| AMY Swann Limited | Arts & recreation | 2025 |
| Amyor Limited | Financial services | 2025 |
| ANA Yardley Ltd | Administrative & support | 2022 |
| Anacymis Ltd | Health & social care | 2021 |
| Anamat Limited | Professional & scientific | 2022 |
| Ancaro Limited | Extraterritorial | 2023 |
| Anchor Cleaning Services Limited | Administrative & support | 2006 |
| Anchor Group Services Ltd | Administrative & support | 2006 |
| Anchor Security Services Limited | Administrative & support | 1990 |
| Anchor Service and Repair Centre Ltd | Wholesale & retail | 2024 |
| Anda Technology Limited | Professional & scientific | 2020 |
| Andamiph Holdings Limited | Professional & scientific | 2023 |
| Andamiph Properties Limited | Professional & scientific | 2023 |
| Anderton Grange (Northwich) Management Company Limited | Households | 2003 |
| Andhil Limited | Professional & scientific | 2018 |
| Andpa Limited | Health & social care | 2018 |
| Andre.J.Wright Homeright Ltd | Other services | 2025 |
| Andree Loves Limited | Health & social care | 2023 |
| Andreea Dragan Ltd | Wholesale & retail | 2019 |
| Andrew Ardern Limited | Information & communication | 2015 |
| Andrew C Kitchens Ltd | Construction | 2023 |
| Andrew Chatten Organ Builders Ltd | Other services | 2023 |
| Andrew Clifford Hairdressing Limited | Other services | 2007 |
| Andrew G Titchener Limited | Health & social care | 2014 |
| Andrew Haxton & Co Limited | Financial services | 2006 |
| Andrew Kane Holdings Ltd | Financial services | 2024 |
| Andrew Lucas Wealth Management Limited | Professional & scientific | 2018 |
| Andrew Michael Noons Ltd | Extraterritorial | 2025 |
| Andrew Norton Limited | Wholesale & retail | 2007 |
| Andrew Plant Consulting Ltd | Professional & scientific | 2023 |
| Andrew Rainford Surveying Limited | Financial services | 2015 |
| Andy Evans Building & Groundworks Services Limited | Construction | 2007 |
| Andy Farrall Limited | Professional & scientific | 2019 |
| Anel Engineering & Contracting Limited | Construction | 2017 |
| Anewarc Limited | Education | 2017 |
| Angela Ileana Fort Ltd | Administrative & support | 2016 |
| Angela Latham Psychology Services Limited | Health & social care | 2016 |
| Angela's Massages Limited | Other services | 2020 |
| Anger Mgmt Holdings Limited | Financial services | 2025 |
| Anger Mgmt Marketing Limited | Professional & scientific | 2021 |
| Anger Mgmt Venues Limited | Administrative & support | 2017 |
| Angharad Vashé Limited | Other services | 2026 |
| Anglesey Construction Ltd | Construction | 2021 |
| Anglesey Lodge & Caravan Park Limited | Real estate | 2004 |
| Anglesey Sea ZOO Marine Conservation Centre Limited | Arts & recreation | 2011 |
| Anglo China Starts Here Limited | Wholesale & retail | 2015 |
| Angus PM Limited | Construction | 2012 |
| Animal Bedding Products Ltd | Agriculture & fishing | 2006 |