| Allegion Safety & Security Solutions Limited | Manufacturing | 2000 |
| Allen & Allen Consultants Ltd | Administrative & support | 2013 |
| Allen-Mullen PUB Co. Limited | Professional & scientific | 2017 |
| Allsorts Accessories Ltd | Wholesale & retail | 2013 |
| Allsports.Co.Uk Limited | Professional & scientific | 1971 |
| Alltricks Automotive Limited | Wholesale & retail | 2023 |
| ALM IT Consulting Ltd | Information & communication | 2011 |
| ALM News Channel Ltd | Information & communication | 2023 |
| Almas Developments Ltd | Real estate | 2023 |
| Almas Trading Ltd | Wholesale & retail | 2022 |
| Almo Glazing Limited | Manufacturing | 2011 |
| Almyra Finance Ltd | Financial services | 2023 |
| Alpha Designs (NW) Ltd | Manufacturing | 2019 |
| Alpha Hedonist Enterprises Ltd | Wholesale & retail | 2025 |
| Alpha Public Relations Limited | Professional & scientific | 2017 |
| Alpine Bidco Limited | Professional & scientific | 2018 |
| Alpine Fire Engineers Limited | Construction | 1992 |
| Alpine Midco Limited | Professional & scientific | 2018 |
| Alpine Topco Limited | Professional & scientific | 2018 |
| Alpo Clothing Ltd | Wholesale & retail | 2025 |
| ALS Protect Limited | Financial services | 2026 |
| ALT House Ltd | Real estate | 2021 |
| Alternative Approach Group Ltd | Health & social care | 2025 |
| Alternative Arrangements Ltd | Wholesale & retail | 2013 |
| Altitude Processing Ltd | Information & communication | 2021 |
| Always Available Vending Limited | Wholesale & retail | 2014 |
| Always Wanted to CIC | Health & social care | 2024 |
| AM & CM Ltd | Hospitality | 2023 |
| AM Auto Ltd | Administrative & support | 2007 |
| AM Carpentry & Joinery Ltd | Construction | 2019 |
| AM Civil Solutions Ltd | Professional & scientific | 2026 |
| AM Design & Creative Limited | Administrative & support | 2013 |
| AM Home Appliances Ltd | Wholesale & retail | 2019 |
| AM Sofa Ltd | Other services | 2020 |
| AM Xtech Ltd | Wholesale & retail | 2026 |
| AM1985 Limited | Professional & scientific | 2014 |
| AMA FIC Ltd | Real estate | 2015 |
| Amacor (Llangollen) Limited | Wholesale & retail | 2018 |
| Amacor Capital Limited | Financial services | 2018 |
| Amarkhil UK Ltd | Real estate | 2026 |
| Amaze Products Limited | Wholesale & retail | 2015 |
| Amber EV Limited | Other services | 2021 |
| Amberend Limited | Construction | 2021 |
| Ambient Psychology Ltd | Health & social care | 2025 |
| AMC Case Management Ltd | Health & social care | 2024 |
| Amelia Leigh Consulting Limited | Professional & scientific | 2021 |
| Amenity Capital Limited | Real estate | 2024 |
| Amephie Holdings Limited | Financial services | 2025 |
| Amethorpe Property Services Limited | Construction | 2008 |
| AMG Business Coaching Ltd | Professional & scientific | 2023 |
| AMG Properties Limited | Real estate | 2016 |
| Amiga Capital Limited | Real estate | 2024 |
| Amino Data Holdings Limited | Financial services | 2023 |
| Amkhan Holdings Ltd | Financial services | 2026 |
| Amore BL9 Limited | Hospitality | 2024 |
| Amour Properties North West Ltd | Real estate | 2020 |
| AMP Electrical Contractors (Manchester) Limited | Administrative & support | 2020 |
| AMS Property Group Ltd | Real estate | 2022 |
| Amsew Consultancy Ltd | Other services | 2020 |
| Amska Mardin Limited | Professional & scientific | 2011 |
| Amsl Enterprises Limited | Real estate | 2013 |
| AMY Jones Hypnotherapy Limited | Other services | 2023 |
| AMY Louise Virtual PA Ltd | Other services | 2024 |
| AMY the JET SET Lifestyle Group Ltd | Professional & scientific | 2021 |
| Amy's Gift Studio Ltd | Wholesale & retail | 2025 |
| Anacompany Ltd | Hospitality | 2025 |
| Anaconda Debt Recovery Ltd | Administrative & support | 2021 |
| Analyzeitpmc Limited | Professional & scientific | 2020 |
| Ananda Reflexology Ltd | Professional & scientific | 2022 |
| Anaugi Limited | Wholesale & retail | 2024 |
| Anay Homes Limited | Information & communication | 2015 |
| Ancla Global Ltd. | Construction | 2019 |
| Ancoats Management Company Limited | Households | 2002 |
| Ancora Imparo Ltd | Education | 2023 |
| AND Newton Limited | Other services | 2025 |
| Anderson Pubs & Leisure Limited | Hospitality | 2017 |
| Andrea Lynette-Young Ltd | Education | 2015 |
| Andrew Gaffey Limited | Professional & scientific | 2020 |
| Andrew Shaw Computer Services Ltd | Information & communication | 2019 |
| Andrewits Ltd | Information & communication | 2019 |
| Andwell Holdings Ltd | Real estate | 2019 |
| Andy Nolan MCR Limited | Administrative & support | 2024 |
| Angel Bury Ltd | Hospitality | 2026 |
| Angela Graham BAT Consultancy Service Limited | Professional & scientific | 2011 |
| Angeloz Ltd | Hospitality | 2026 |
| Angle Plant Hire Ltd. | Construction | 1997 |
| Animal Connections CIC | Agriculture & fishing | 2025 |
| Animal Lifeaid | Extraterritorial | 2017 |
| Anis Motors Ltd | Wholesale & retail | 2023 |
| Anka Associates Ltd | Administrative & support | 2017 |
| Annshawmaintain Ltd | Construction | 2022 |
| Annshores and Hills Ltd | Real estate | 2022 |
| Anotherway Coaching & Training Solutions Ltd | Professional & scientific | 2016 |
| ANP Contracts Limited | Extraterritorial | 2020 |
| Anson Contractors Ltd | Transport & logistics | 2015 |
| Anson Hayward Limited | Information & communication | 2026 |
| Anthony Hill Ltd | Manufacturing | 2024 |
| Anthony Marshall Holdings Limited | Financial services | 2019 |
| Anthony Marshall Ltd | Professional & scientific | 1997 |
| Anthony Sheridan Limited | Professional & scientific | 2015 |