| Aiginger Prof. HEA Ltd | Administrative & support | 2016 |
| Aigm Ltd | Professional & scientific | 2025 |
| Aihan Mini Market Limited | Wholesale & retail | 2026 |
| Aileen Morrison Psychologist Ltd | Health & social care | 2026 |
| Ailsa House (Leeds) Management Company Limited | Households | 2025 |
| AIM Vision Ltd | Wholesale & retail | 2024 |
| Aima Business and Medical Support UK Ltd | Professional & scientific | 2019 |
| Aima Investments Ltd | Financial services | 2022 |
| Aina Consultancy Limited | Professional & scientific | 2011 |
| Ainsworth Print & Design Holdings Ltd | Financial services | 2025 |
| Ainsworth Print & Design Limited | Manufacturing | 1995 |
| Ainsworth Rise Management Company Limited | Households | 2007 |
| Aipim Ltd | Hospitality | 2022 |
| Aiquarter Limited | Information & communication | 2018 |
| Air CON (Manchester) Limited | Construction | 2013 |
| Air Cooling Products Ltd | Construction | 2018 |
| Air on Services Ltd | Energy | 2017 |
| Air Rentals Limited | Professional & scientific | 1976 |
| Air Sea Land Worldwide Ltd | Transport & logistics | 2022 |
| Air Service Tromsoe Ltd | Administrative & support | 2006 |
| Air Technique Filtration Limited | Construction | 2016 |
| Air Utilities Limited | Construction | 2020 |
| Air&Cloud Balloon Ltd | Hospitality | 2018 |
| Air-Tech Direct Limited | Administrative & support | 2006 |
| Aira Retail Ltd | Wholesale & retail | 2025 |
| Airbourne Business Support Limited | Administrative & support | 2021 |
| Airbrit Ltd | Wholesale & retail | 2022 |
| Airline Avionics Limited | Manufacturing | 2010 |
| Airport Taxi Association (ATA) Ltd | Transport & logistics | 2022 |
| Airriess Construction and Engineering Ltd | Professional & scientific | 2026 |
| Aivt Consulting Ltd | Professional & scientific | 2025 |
| AJ Care Group Ltd | Health & social care | 2026 |
| AJ Estates Ribchester Ltd | Real estate | 2019 |
| AJ Food and Wine Store Limited | Wholesale & retail | 2023 |
| AJ Holland Property Limited | Real estate | 2020 |
| AJ IT Specialist Ltd | Professional & scientific | 2025 |
| AJ Mccormick Ltd | Information & communication | 2016 |
| AJ Mech Engineering Ltd | Professional & scientific | 2025 |
| AJ Media & Marketing Limited | Information & communication | 2024 |
| AJB CAD Services Limited | Professional & scientific | 2008 |
| AJB Projects Limited | Construction | 2025 |
| AJC Analysis Limited | Information & communication | 1997 |
| AJD & Co Ltd | Real estate | 2023 |
| AJF Consultancy Limited | Information & communication | 2007 |
| AJK Developers Ltd | Real estate | 2020 |
| AJL Civils & Plant Ltd | Construction | 2023 |
| AJL Repair Services Ltd | Construction | 2023 |
| AJL785 Limited | Real estate | 2023 |
| AJM Coffee Limited | Hospitality | 2021 |
| AJM Drywall Ltd | Construction | 2021 |
| AJM Housing Ltd | Real estate | 2016 |
| AJP Audio Ltd | Information & communication | 2022 |
| AJR Innovations Limited | Professional & scientific | 2016 |
| AJR Productions Ltd | Arts & recreation | 2018 |
| AJS Health Limited | Health & social care | 2016 |
| AJS Invest Ltd | Administrative & support | 2007 |
| AJT Data Ltd | Information & communication | 2025 |
| AJT Health Economics Limited | Health & social care | 2020 |
| AJT Properties Limited | Real estate | 2021 |
| Ajwh Consultancy Ltd | Information & communication | 2024 |
| AK Errands Limited | Wholesale & retail | 2024 |
| AK Green Ltd | Information & communication | 2020 |
| AK Homes (NW) Ltd | Real estate | 2019 |
| AK Plant Design Engineering Limited | Professional & scientific | 2018 |
| AK Roofing Specialists Ltd | Construction | 2023 |
| AK Severn Holdings Ltd | Financial services | 2019 |
| AK Silver Ltd | Information & communication | 2021 |
| AK54PHOTO Limited | Professional & scientific | 2014 |
| AKA Bespoke Investments Limited | Wholesale & retail | 2011 |
| AKA Fitness Ltd | Arts & recreation | 2023 |
| Akademiai Ltd | Information & communication | 2025 |
| Akademy Centre of Excellence C.I.C. | Education | 2022 |
| AKC Consulting Ltd | Information & communication | 2023 |
| Akeroyds Limited | Construction | 2012 |
| Akhtar Productions Limited | Arts & recreation | 2024 |
| Akhtar Properties (Manchester) Limited | Real estate | 2017 |
| Akin FC Ltd | Hospitality | 2021 |
| Akkamedia Limited | Information & communication | 2007 |
| Akline Business Ltd | Real estate | 2025 |
| AKM Housing Ltd | Real estate | 2026 |
| Akme Building Solutions Ltd | Construction | 2026 |
| AKN Law Limited | Professional & scientific | 2020 |
| Akom Ltd | Information & communication | 2024 |
| Akroyd's Caravan Storage Ltd | Real estate | 2012 |
| Aksul Ltd | Hospitality | 2022 |
| Aktiv Fotklinikk Ltd | Administrative & support | 2008 |
| Akuda Ltd. | Information & communication | 2012 |
| Akutt Roerleggerhjelp Ltd | Administrative & support | 2009 |
| Akwa Solutions Limited | Water & waste | 2007 |
| Akwil Limited | Information & communication | 2015 |
| Akztok Ltd | Wholesale & retail | 2025 |
| AL Building Safety Compliance and Remediation Ltd | Professional & scientific | 2026 |
| AL Collister Design Limited | Administrative & support | 2011 |
| AL Hassan OIL Consultants (Private) Ltd | Information & communication | 2024 |
| AL Homes SPV Limited | Real estate | 2017 |
| AL Kauther Ltd | Hospitality | 2017 |
| AL Layali Ltd | Wholesale & retail | 2025 |
| AL Medical Aesthetics & Wellness Ltd | Other services | 2019 |
| AL Mughni Souq Ltd | Wholesale & retail | 2025 |
| AL Pacinos Pizza House Ltd | Hospitality | 2016 |