| Air Control Concepts UK Ltd | Wholesale & retail | 2025 |
| Airangel Limited | Professional & scientific | 2003 |
| Airbotics Talent Ltd | Administrative & support | 2023 |
| Airline Placement Limited | Other services | 2004 |
| Airofin Trading Limited | Information & communication | 2024 |
| Aisha Consultancy Ltd | Other services | 2025 |
| Aitech Services Ltd | Information & communication | 2021 |
| AIU Services Ltd | Professional & scientific | 2022 |
| Aivohrait Ltd | Information & communication | 2025 |
| AIX Live Limited | Other services | 2020 |
| Aiyo International Ltd | Wholesale & retail | 2017 |
| AJ & H Ltd | Professional & scientific | 2022 |
| AJ Barnes Financial Planning Ltd | Professional & scientific | 2018 |
| AJ Glass and Glazing (NW) Limited | Construction | 2022 |
| AJ Health Solution Ltd | Health & social care | 2024 |
| AJ Smiles Ltd | Health & social care | 2022 |
| AJ Urology Ltd | Health & social care | 2026 |
| Ajae Consulting Ltd | Information & communication | 2026 |
| Ajaex Ltd | Information & communication | 2022 |
| Ajdj Limited | Health & social care | 2021 |
| AJH Compliance Consulting Limited | Professional & scientific | 2025 |
| AJH Joinery (MCR) Limited | Manufacturing | 2022 |
| AJH UX Limited | Professional & scientific | 2022 |
| Ajkam Ltd | Administrative & support | 2017 |
| AJM Steel Solutions Ltd | Construction | 2025 |
| Ajnp Ltd | Real estate | 2024 |
| AJR Management Consultancy Limited | Administrative & support | 2023 |
| AJR Retail Ltd | Hospitality | 2024 |
| AK Audio Services Ltd | Information & communication | 2026 |
| AK Legal Consultantcy Limited | Professional & scientific | 2025 |
| AK Locks Limited | Other services | 2024 |
| AK Medics Limited | Health & social care | 2019 |
| AK Properties (Macclesfield) Limited | Real estate | 2020 |
| AK Properties (Yorkshire) Ltd | Real estate | 2020 |
| AK Raglan Investments Limited | Financial services | 2025 |
| AK Reward Limited | Professional & scientific | 2017 |
| AKG Logistic Consultancy Limited | Administrative & support | 2017 |
| AKH Project Solutions Limited | Administrative & support | 2007 |
| Akkroo Solutions Limited | Information & communication | 2013 |
| Akksan Properties Ltd | Real estate | 2021 |
| Aknr Limited | Real estate | 2025 |
| Akolawole Limited | Professional & scientific | 2026 |
| Akorn Consultants Limited | Professional & scientific | 2023 |
| Akpan Limited | Professional & scientific | 2023 |
| Akplumbinggroup Ltd | Construction | 2024 |
| Akuna Europe Limited | Administrative & support | 2012 |
| Akuonu Ventures Ltd | Health & social care | 2026 |
| AL Holmes Limited | Professional & scientific | 2024 |
| AL Khans Limited | Hospitality | 2021 |
| AL Nimra (School) Ltd | Education | 2019 |
| AL Safety Managment Limited | Administrative & support | 2016 |
| AL Themaid Limited | Real estate | 2023 |
| Al'Fix Ltd | Construction | 2026 |
| Al-Arabiworldwide Limited | Wholesale & retail | 2025 |
| Al-Wadi Homes Ltd | Real estate | 2023 |
| AL002 Limited | Real estate | 2022 |
| AL004 Limited | Real estate | 2021 |
| Alan DE Maid Limited | Professional & scientific | 2010 |
| Alan Garner Limited | Extraterritorial | 1972 |
| Alauna Safety Solutions Limited | Professional & scientific | 2024 |
| ALB Insights & Performance Ltd | Health & social care | 2025 |
| Alberbury Consulting Limited | Professional & scientific | 2019 |
| Albert Gubay Trustee Limited | Professional & scientific | 2021 |
| Albert Hill Limited | Real estate | 1989 |
| Albert Square Estates Ltd | Construction | 2016 |
| Albertginglefish & Co Limited | Financial services | 2020 |
| Albinea Limited | Professional & scientific | 2023 |
| Albinsons Limited | Real estate | 2024 |
| Albion Systems Limited | Manufacturing | 1997 |
| Alcram Electrical Ltd | Construction | 2013 |
| Aldan Ventures Ltd | Real estate | 2021 |
| Aldean Property Management Ltd | Real estate | 2018 |
| Alder Blossom Ltd | Real estate | 2026 |
| Alder Heights Management Company Limited | Households | 2003 |
| Alderbank Residents Association Limited | Other services | 2026 |
| Alderley Lodge Limited | Households | 1970 |
| Aldersgate Funding Limited | Financial services | 2019 |
| Aldrich Investments Ltd | Real estate | 2023 |
| Alemara Limited | Financial services | 2022 |
| Alero Land Limited | Administrative & support | 2008 |
| Aleta Biotherapeutics Ltd | Professional & scientific | 2026 |
| Alex Beswick Property Limited | Real estate | 2016 |
| Alexander Administration Ltd | Real estate | 2025 |
| Alexander Europe Limited | Administrative & support | 2017 |
| Alexander Grace & Partners Ltd | Administrative & support | 2012 |
| Alexander House Financial Planning Limited | Financial services | 2017 |
| Alexander House Financial Services Limited | Financial services | 2013 |
| Alexander House Ltd | Financial services | 2021 |
| Alexander Knight & Associates Limited | Extraterritorial | 2024 |
| Alexander Knight & Co Limited | Professional & scientific | 2012 |
| Alexander Livestock Limited | Agriculture & fishing | 2018 |
| Alexander Trailers Limited | Manufacturing | 2006 |
| Alexandra FOX North Limited | Real estate | 2017 |
| Alexhurst Limited | Professional & scientific | 1984 |
| Alexia MAY Limited | Real estate | 2020 |
| Alexmed Ltd | Health & social care | 2009 |
| Alfa Driving School Ltd | Information & communication | 2022 |
| Alfa Parf UK Ltd | Wholesale & retail | 2019 |
| Alford-Leach Holdings Limited | Professional & scientific | 2025 |
| Alfred Lamb International Limited | Administrative & support | 2006 |