| Altivon Limited | Wholesale & retail | 2026 |
| Alton Accountancy and Tax Limited | Professional & scientific | 2024 |
| Alton B&B Limited | Hospitality | 2024 |
| Alton Bhinn Ltd | Hospitality | 2024 |
| Alton Bridge Hatch Limited | Hospitality | 2022 |
| Alton Bridge Hotel Limited | Hospitality | 2013 |
| Alton Care Ltd | Administrative & support | 2021 |
| Altrincham Construction Ltd | Construction | 2023 |
| Aluminium Products Worldwide Limited | Wholesale & retail | 2026 |
| Always UP Ltd | Transport & logistics | 2019 |
| Alwayssecure Ltd | Administrative & support | 2025 |
| Alwell Ltd | Information & communication | 2020 |
| Alyzen Ltd | Wholesale & retail | 2026 |
| AM 247 Ltd | Information & communication | 2021 |
| AM Access Ltd | Extraterritorial | 2010 |
| AM Auto Mechanics Ltd | Wholesale & retail | 2017 |
| AM Designs Studio Ltd | Professional & scientific | 2023 |
| AM Plumbing & Heating (Staffordshire) Limited | Construction | 2015 |
| AM PM Base Limited | Professional & scientific | 2024 |
| AM Recovery and Tyres Ltd | Transport & logistics | 2025 |
| AM Scaffolding Services Limited | Construction | 2003 |
| AMA Insurance Services Ltd | Financial services | 2009 |
| AMA Private Ltd | Health & social care | 2022 |
| Amaam Global Ltd | Wholesale & retail | 2017 |
| Amadeus Music Academy Limited | Education | 2017 |
| Amala Petfoods Limited | Wholesale & retail | 2015 |
| Amanah Ltd | Administrative & support | 2023 |
| Amanah Private Capital Management Ltd | Financial services | 2026 |
| Amanda Butler Limited | Professional & scientific | 2008 |
| Amanda Copeland Hair & Beauty Limited | Other services | 2018 |
| Amansellers Limited | Extraterritorial | 2024 |
| Amari SG Limited | Other services | 2025 |
| Amarss Ltd | Hospitality | 2021 |
| Amavic Group Ltd | Administrative & support | 2023 |
| Amaziah Ltd | Wholesale & retail | 2020 |
| Amazing Angels Care Ltd | Administrative & support | 2020 |
| Amazing Angels Consulting Services Ltd | Administrative & support | 2025 |
| Amazing Favour Consultant Limited | Health & social care | 2019 |
| Amazing Giveaways Ltd | Other services | 2024 |
| AMB Mechanical Ltd | Construction | 2024 |
| Ambassador Road RTM Company Limited | Households | 2026 |
| Ambc (NW) Limited | Construction | 2024 |
| Ambiance Salons Limited | Other services | 2016 |
| Amco Building Supplies Limited | Wholesale & retail | 2022 |
| Amco Group(Uk) Ltd | Professional & scientific | 2021 |
| Amcorner Ltd | Wholesale & retail | 2026 |
| AMD Business Consulting Ltd | Administrative & support | 2014 |
| Amelin Commercial Limited | Professional & scientific | 2023 |
| Amethyst Oak Incorporated Limited | Real estate | 2022 |
| Amflo Group Ltd | Real estate | 2024 |
| AMG Refrigeration & Air Conditioning Limited | Other services | 2014 |
| AMH Web Services Ltd | Information & communication | 2023 |
| Amigos Logistics Ltd | Transport & logistics | 2026 |
| Amiphany Group Limited | Administrative & support | 2023 |
| Amisd Limited | Wholesale & retail | 2021 |
| Amison Electrical Ltd | Construction | 2024 |
| Amjpubco Ltd | Hospitality | 2026 |
| AML Electrical Services Limited | Construction | 2002 |
| AMM Properties Stoke Ltd | Real estate | 2019 |
| Ammocom Holdings Limited | Financial services | 2023 |
| Amorapia Holdings Ltd | Financial services | 2026 |
| Amore DE Madre Ltd | Real estate | 2022 |
| Amos Contracting Ltd | Construction | 2015 |
| AMP Creative Ltd | Information & communication | 2017 |
| AMP Recruitment Ltd | Administrative & support | 2022 |
| Amp-Coaching and Consulting Ltd | Health & social care | 2024 |
| Amrachi Ltd | Wholesale & retail | 2026 |
| Amro Catering Ltd | Hospitality | 2021 |
| AMS Commercial 1 Ltd | Real estate | 2024 |
| AMS Landscapes Cheshire Ltd | Administrative & support | 2022 |
| AMS Properties 1 Limited | Real estate | 2023 |
| AMS Wholsesale 1 Limited | Wholesale & retail | 2024 |
| Amshine Limited | Real estate | 2004 |
| AMT123 Limited | Transport & logistics | 2025 |
| AMW Consultancy Ltd | Information & communication | 2025 |
| AMW Investments Limited | Financial services | 2021 |
| Amwell Laminates Limited | Wholesale & retail | 1980 |
| AN Apple a Day (Juice Bar) Ltd | Hospitality | 2016 |
| AN Nails & Beauty Limited | Other services | 2026 |
| AN Property Lifestyle Limited | Real estate | 2016 |
| Anamzooya’S Healthcare Ltd | Health & social care | 2021 |
| Anare Tomasi Ltd | Construction | 2015 |
| Anasma Ltd | Hospitality | 2017 |
| Anastas&Antoilinca Ltd | Transport & logistics | 2018 |
| Anatomy Physiotherapy Practice Ltd | Health & social care | 2026 |
| Anay Food Limited | Hospitality | 2022 |
| Anaya Online Limited | Wholesale & retail | 2025 |
| Anchor Service Solutions Limited | Real estate | 2024 |
| Andacom Ltd | Professional & scientific | 2024 |
| Andakmotion Ltd | Information & communication | 2023 |
| Anderson Engineering Solutions Limited | Professional & scientific | 2003 |
| Anderson Yorke Associates Limited | Professional & scientific | 2006 |
| Anderton Port Limited | Real estate | 2007 |
| Andmart Ltd | Construction | 2022 |
| Andreas Robert Sandberg Comp Limited | Wholesale & retail | 2025 |
| Andrei Pluming Ltd | Construction | 2025 |
| Andrei&Vali Limited | Transport & logistics | 2018 |
| Andrew Barnes Cabinet Maker Limited | Manufacturing | 2024 |
| Andrew Downes Limited | Professional & scientific | 2016 |
| Andrew Edwards Consultancy Limited | Professional & scientific | 2026 |