| Amethyst Medical Secretarial Service Limited | Administrative & support | 2010 |
| Amethyst Technical Services Ltd | Administrative & support | 2022 |
| Ameunier Limited | Information & communication | 2020 |
| AMG Lifting LAB Ltd | Arts & recreation | 2018 |
| AMH Analysis Limited | Professional & scientific | 2016 |
| Amine Dahimene Ltd | Administrative & support | 2022 |
| AMJ Autos Ltd | Wholesale & retail | 2025 |
| Amjad Apex Dream Ltd | Wholesale & retail | 2025 |
| AMK IR Limited | Professional & scientific | 2021 |
| Ammonite Healthcare Limited | Administrative & support | 2011 |
| Amnis Holdings Limited | Real estate | 2024 |
| AMO Consultancy Limited | Information & communication | 2011 |
| AMO Gbro Ltd | Transport & logistics | 2017 |
| AMO7 Ltd | Hospitality | 2023 |
| Amoda Beauty Ltd | Other services | 2016 |
| Amoda Skin Limited | Other services | 2023 |
| Amogen Consulting Limited | Information & communication | 2020 |
| Amoil Supplies Limited | Extraterritorial | 1997 |
| Amoria Children's Residential Ltd | Health & social care | 2024 |
| AMP Athletic Limited | Health & social care | 2017 |
| Ampate Limited | Administrative & support | 2025 |
| Amped Consultancy Ltd | Professional & scientific | 2018 |
| Ampera Raya Limited | Administrative & support | 2018 |
| Amplified Music School Ltd | Education | 2022 |
| Amplify Associates Limited | Professional & scientific | 2018 |
| Amplyne Ltd | Professional & scientific | 2025 |
| Ampthill Road (Beadlow) Ltd | Construction | 2019 |
| Ampus Ltd | Administrative & support | 2026 |
| Amssal Ltd | Hospitality | 2010 |
| Amsvision Holdings Limited | Financial services | 2022 |
| Amsvision Ltd | Information & communication | 2013 |
| Amtec Consultants Limited | Professional & scientific | 1992 |
| Amtec Corrosion Limited | Professional & scientific | 1986 |
| AMW Finance Limited | Financial services | 2006 |
| AMY Clark Consultancy Ltd | Professional & scientific | 2024 |
| AMY Sarah Daniel Properties Ltd | Households | 2026 |
| AMZ Engineering Limited | Wholesale & retail | 2016 |
| AN QA Solutions Limited | Information & communication | 2019 |
| Analogue Baby Limited | Other services | 2010 |
| Analysight Limited | Information & communication | 2009 |
| Analysis DC Limited | Professional & scientific | 2024 |
| Anansi JJ Limited | Wholesale & retail | 2019 |
| Anareli Ltd | Other services | 2025 |
| Anartech Limited | Information & communication | 2012 |
| Anayex Ltd | Administrative & support | 2025 |
| ANB Instrument & Control Services Ltd | Construction | 2024 |
| Anchor & Atlas Group Ltd | Transport & logistics | 2025 |
| Anchor & Hops Ltd | Hospitality | 2020 |
| Anchor Brickwork AK Ltd | Construction | 2022 |
| Anchor Fire Protection Ltd | Professional & scientific | 2025 |
| Anchor Pumps Company Limited | Wholesale & retail | 1987 |
| Ancoats Express Limited | Real estate | 2024 |
| AND & Dary Ltd | Transport & logistics | 2018 |
| Andem (Navenby) Limited | Real estate | 1998 |
| Anden Composites Ltd | Administrative & support | 2025 |
| Anderlec Contracts Ltd | Construction | 2024 |
| Anders LAD & DAD Carpet & Upholstery Cleaning Services Ltd | Administrative & support | 2025 |
| Andersley Tech Ltd | Information & communication | 2021 |
| Anderson Automation Consultancy Limited | Professional & scientific | 2016 |
| Anderson Baillie Management Limited | Professional & scientific | 2013 |
| Anderson Goddard Limited | Professional & scientific | 2003 |
| Andi Ltd | Transport & logistics | 2015 |
| Andover Property Company Ltd | Construction | 2019 |
| Andrax Engineering Ltd | Information & communication | 2015 |
| Andrax Holdings Ltd | Real estate | 2026 |
| Andrax Tech Services Ltd | Information & communication | 2025 |
| Andrea Floris Design Ltd | Professional & scientific | 2024 |
| Andreano Consultants Limited | Information & communication | 2018 |
| Andrei Ciobanu Ltd | Transport & logistics | 2020 |
| Andrei Sabin Logistic Ltd | Transport & logistics | 2019 |
| Andrei Traian Iana Ltd | Information & communication | 2025 |
| Andreitransport Ltd | Transport & logistics | 2026 |
| Andrew Cartwright Limited | Administrative & support | 2025 |
| Andrew Collins Beauty Company Limited | Other services | 2020 |
| Andrew Collins Hairdressing Limited | Other services | 2018 |
| Andrew Dedman Ltd | Information & communication | 2020 |
| Andrew FOX IT Limited | Information & communication | 2018 |
| Andrew Langdon Ltd | Health & social care | 2018 |
| Andrew LEE Engineering Limited | Administrative & support | 2010 |
| Andrew Ling Technical Services Limited | Administrative & support | 2012 |
| Andrew Rowe Consulting Ltd | Administrative & support | 2026 |
| Andrew Small Engineering Services Limited | Administrative & support | 2008 |
| Andrew Smith Engineering Ltd | Professional & scientific | 2022 |
| Andrew Terry Consulting Ltd | Information & communication | 2015 |
| Andrioli Consultancy Services Ltd | Administrative & support | 2025 |
| Andron Facilities Management Limited | Administrative & support | 2021 |
| Andronic Valy Ltd | Transport & logistics | 2018 |
| Andy & Leah Properties Ltd | Real estate | 2022 |
| Andy Boyce Limited | Professional & scientific | 2018 |
| Andy Skelton Transport Limited | Transport & logistics | 2021 |
| Andy's BUS Company Limited | Transport & logistics | 2007 |
| Andypkg Ltd | Wholesale & retail | 2014 |
| Aneblans Investments Limited | Real estate | 1959 |
| Anewal Ltd | Wholesale & retail | 2023 |
| ANF Consultancy Ltd | Administrative & support | 2019 |
| ANG Estates Limited | Real estate | 2020 |
| Angel Advance Limited | Financial services | 2012 |
| Angel Diagnostics Limited | Professional & scientific | 2021 |
| Angel Hire Limited | Administrative & support | 1999 |
| Angel Lane Communications Limited | Professional & scientific | 2020 |