| Annie Homes Ltd | Households | 2025 |
| Annie Star Limited | Wholesale & retail | 2025 |
| Annjewel Consult Ltd | Administrative & support | 2017 |
| Anny African Delicacies Ltd | Hospitality | 2021 |
| Anokye Limited | Information & communication | 2012 |
| Anomansa Limited | Information & communication | 2017 |
| ANQ Global Traders Ltd | Wholesale & retail | 2026 |
| ANR 2015 Limited | Other services | 2015 |
| Anritsu Emea Limited | Other services | 2006 |
| ANS JL Limited | Administrative & support | 2016 |
| Ansari Property Investments Limited | Real estate | 2018 |
| Anse Ltd | Information & communication | 2025 |
| Ansuron Consultancy Limited | Professional & scientific | 2019 |
| Answerpoint Limited | Administrative & support | 2001 |
| ANT Transport Ltd | Transport & logistics | 2023 |
| Anthill Networks Limited | Information & communication | 2025 |
| Antium Property Management Company Limited | Real estate | 2018 |
| Antoce Removals Limited | Transport & logistics | 2026 |
| Anton Paar Ltd | Administrative & support | 1982 |
| Antonia Lisca Ltd | Arts & recreation | 2024 |
| Antonia Maria Joint Ltd | Construction | 2025 |
| Antonyo.Construction&Welding Ltd | Construction | 2026 |
| Antorina Ltd | Transport & logistics | 2017 |
| Antwiwaah Services Limited | Health & social care | 2021 |
| ANU Property Services Limited | Real estate | 2020 |
| Anwar Tyres Fitting Services Ltd | Wholesale & retail | 2021 |
| Anwazra Ltd | Real estate | 2025 |
| Anyre Limited | Wholesale & retail | 2026 |
| Anyservs Limited | Other services | 2022 |
| AO Green Properties Limited | Construction | 2024 |
| AO Home Group Limited | Financial services | 2024 |
| AO Home Lettings Ltd | Real estate | 2023 |
| AO Home Management Ltd | Real estate | 2023 |
| AO Technologies Ltd | Manufacturing | 2013 |
| Aodis Ltd | Wholesale & retail | 2020 |
| AOG Solutions Limited | Information & communication | 2006 |
| AP Car Care & Tyres Limited | Wholesale & retail | 2018 |
| AP Cargus Limited | Construction | 2023 |
| AP Civil Surfacing Ltd | Construction | 2025 |
| AP Design Ltd | Wholesale & retail | 2015 |
| AP Keshav Ltd | Wholesale & retail | 2022 |
| AP Systems Ltd | Information & communication | 2011 |
| AP365 Ltd | Administrative & support | 2021 |
| Apata Intercontinental Limited | Hospitality | 2023 |
| APC Futures Ltd | Professional & scientific | 2009 |
| Apelan Ltd | Construction | 2026 |
| Apelka Ltd | Transport & logistics | 2024 |
| Apex Building Consultants Limited | Professional & scientific | 2010 |
| Apex Alloys Ltd | Wholesale & retail | 2022 |
| Apex Aromas Ltd | Wholesale & retail | 2025 |
| Apex Brüders Ltd | Wholesale & retail | 2024 |
| Apex Business Support & Digital Operations Ltd | Transport & logistics | 2026 |
| Apex Care Group Limited | Health & social care | 2020 |
| Apex Co. Retail Limited | Wholesale & retail | 2026 |
| Apex Core Technologies Limited | Information & communication | 2025 |
| Apex Finance Partners Ltd | Professional & scientific | 2023 |
| Apex Financial Services Ltd | Financial services | 2026 |
| Apex Franchises Ltd | Information & communication | 2017 |
| Apex Global Textile Sourcing Ltd | Wholesale & retail | 2026 |
| Apex Live Ltd | Arts & recreation | 2026 |
| Apex Luxe Ltd | Professional & scientific | 2025 |
| Apex Motor Solutions Ltd | Wholesale & retail | 2023 |
| Apex Office Interiors Holdings Limited | Financial services | 2015 |
| Apex Plumbing Services Ltd | Construction | 2021 |
| Apex Prime Distributors Ltd | Information & communication | 2023 |
| Apex Pro Builders Ltd | Construction | 2023 |
| Apex Quadraunity Ltd | Wholesale & retail | 2025 |
| Apex Sales & Lettings Limited | Real estate | 2015 |
| Apex Smiles Limited | Health & social care | 2022 |
| Apex Solution Luton Limited | Administrative & support | 2025 |
| Apex Strategic Solutions Ltd | Other services | 2025 |
| Apex Vault Capital Ltd | Professional & scientific | 2025 |
| Apex Windows Limited | Construction | 2012 |
| Apexbuild Properties Limited | Real estate | 1995 |
| Apexia Solutions Ltd | Administrative & support | 2025 |
| APG Building Ltd | Construction | 2026 |
| APG Gardening Limited | Administrative & support | 2009 |
| APH Aviation Services Limited | Transport & logistics | 2011 |
| Aphrodisia Ltd | Wholesale & retail | 2024 |
| Apjg IT Solutions Limited | Wholesale & retail | 2017 |
| APL Express Limited | Other services | 2023 |
| Aplus Properties Services Limited | Other services | 2019 |
| Apnaa Pizza Ltd | Hospitality | 2025 |
| Apni Committee CIC | Health & social care | 2023 |
| APO Delivery Limited | Transport & logistics | 2026 |
| Apocustom Ltd | Wholesale & retail | 2023 |
| Apogeo Investments Ltd | Real estate | 2019 |
| Apothecary Brothers Ltd | Wholesale & retail | 2021 |
| App AE Ltd | Wholesale & retail | 2017 |
| App CAN Limited | Information & communication | 2011 |
| App DEV OPS Ltd | Information & communication | 2020 |
| Appeex Limited | Wholesale & retail | 2025 |
| Apphia Estates Limited | Real estate | 2019 |
| Appirium Limited | Information & communication | 2024 |
| Applecroft Mechanical Fitting Ltd | Other services | 2019 |
| Applerate Limited | Transport & logistics | 2018 |
| Appleton & Howard Ltd. | Professional & scientific | 2008 |
| Appliance Monkeys Limited | Wholesale & retail | 2018 |
| Appliance Warehouse Services Ltd | Other services | 2008 |
| Apply UK International Ltd | Education | 2020 |