| Anra Limited | Wholesale & retail | 2025 |
| Anrish Properties Ltd | Real estate | 2024 |
| ANS IT Consultants Ltd | Information & communication | 2015 |
| Ansa Property Developers Ltd | Real estate | 2021 |
| Anserem Consulting Limited | Professional & scientific | 2023 |
| Anshlar Limited | Administrative & support | 2020 |
| Anshrith Ltd | Real estate | 2022 |
| Anson Trades Ltd | Construction | 2024 |
| Anta Pro Limited | Manufacturing | 2024 |
| Antae Ltd | Wholesale & retail | 2017 |
| Antevia Ltd | Information & communication | 2021 |
| Antheia Consultancy Limited | Information & communication | 2014 |
| Anthony Asbestos Consultancy Ltd | Other services | 2019 |
| Anthony Pollock & Associates Limited | Professional & scientific | 2020 |
| Anthony Toby Homes Trust | Health & social care | 2004 |
| Anthony Travis Limited | Other services | 2022 |
| Anthracite Holdings Ltd | Financial services | 2017 |
| Anton Saws & Machinery Ltd | Wholesale & retail | 2000 |
| Antonella Russo Limited | Professional & scientific | 2016 |
| Antonia Taylor PR + Communications Ltd | Professional & scientific | 2019 |
| Antonio Gabriel Construction Ltd | Construction | 2025 |
| Antriksh Properties Ltd | Real estate | 2021 |
| Antwil Electrical Services Ltd | Construction | 2025 |
| ANU & Kamal Properties Limited | Real estate | 2022 |
| ANU Assets Limited | Real estate | 2026 |
| Anuma Intelligence Ltd | Information & communication | 2025 |
| Anuma Limited | Information & communication | 2013 |
| Anvika Info Limited | Information & communication | 2017 |
| Anviraj Partners Ltd | Real estate | 2023 |
| Anwar Trading Ltd | Hospitality | 2025 |
| ANY Size Ltd | Wholesale & retail | 2022 |
| Anya Rich Accounting Services Limited | Professional & scientific | 2013 |
| Anything Goes Personal Care Ltd. | Wholesale & retail | 2015 |
| Anything Goes Theatre Company Limited | Arts & recreation | 2016 |
| AOG & Pharma Logistics Limited | Transport & logistics | 2019 |
| AOM Associates Ltd | Professional & scientific | 2021 |
| AOM Property Investment Ltd | Real estate | 2022 |
| Aoreun Group Limited | Wholesale & retail | 2026 |
| Aoxna Limited | Extraterritorial | 2023 |
| AP Assemblies Limited | Manufacturing | 2016 |
| AP Gogna Ltd | Health & social care | 2016 |
| AP Mechanical Worx Ltd | Wholesale & retail | 2026 |
| AP Property Renovation Limited | Construction | 2022 |
| Apache Intertrader Limited | Financial services | 2022 |
| APB Colour Print Ltd | Manufacturing | 1972 |
| Apbuk Group Limited | Real estate | 2021 |
| APC Diaspora Women's Congress Ltd | Other services | 2025 |
| Apcl Limited | Information & communication | 2011 |
| Aperio Signals Ltd | Information & communication | 2015 |
| Apex 365 Limited | Information & communication | 2019 |
| Apex 365 Property Ltd | Households | 2024 |
| Apex Access Platforms Ltd | Administrative & support | 2024 |
| Apex ARR Ltd | Professional & scientific | 2026 |
| Apex Bay Solutions Ltd | Wholesale & retail | 2026 |
| Apex Clearance & Recycling Ltd | Water & waste | 2025 |
| Apex Environmental Services (UK) Ltd | Administrative & support | 2017 |
| Apex GAS & Plumbing Services Ltd | Construction | 2025 |
| Apex Giveaways Ltd | Wholesale & retail | 2026 |
| Apex Healthcare Franchise Ltd | Professional & scientific | 2026 |
| Apex Healthcare Services Limited | Health & social care | 2016 |
| Apex Hire Group Ltd | Administrative & support | 2024 |
| Apex Info Media Limited | Wholesale & retail | 2013 |
| Apex International Property Solutions Limited | Real estate | 2023 |
| Apex IT Services Ltd | Information & communication | 2026 |
| Apex IT Solutions & Services Ltd | Information & communication | 2014 |
| Apex Leisure Investments Ltd | Real estate | 2003 |
| Apex Leisure Ltd | Information & communication | 2002 |
| Apex Precision LAB Ltd | Health & social care | 2025 |
| Apex Property (Management & Lettings) Ltd | Households | 2009 |
| Apexb Limited | Other services | 2026 |
| Apexjetwasher Ltd | Other services | 2025 |
| Apexpricing Limited | Administrative & support | 2025 |
| Apg-Neuros Limited | Water & waste | 2015 |
| Apgolf Ltd | Professional & scientific | 2017 |
| APH Technologies Limited | Information & communication | 2011 |
| Aphor Limited | Professional & scientific | 2022 |
| Aphrodite's Beauty Salon Limited | Other services | 2012 |
| API and Apps Ltd | Information & communication | 2021 |
| API Economy Ltd | Information & communication | 2018 |
| Apira Limited | Information & communication | 1997 |
| APJ Holidings Group Limited | Real estate | 2021 |
| APM Education Consultancy Limited | Professional & scientific | 2018 |
| Apnb Ltd | Wholesale & retail | 2025 |
| Apnv Properties Ltd | Real estate | 2023 |
| Apogee Homes Ltd | Real estate | 2018 |
| Apollo Gallery Ltd | Wholesale & retail | 2023 |
| Apollo Gymnastics Academy Limited | Education | 2019 |
| Apollo Search Limited | Administrative & support | 2024 |
| Apollo Surfacing Limited | Construction | 2023 |
| App Collective Limited | Information & communication | 2025 |
| Appclouddroid Ltd | Information & communication | 2020 |
| Appiah Services Limited | Education | 2014 |
| Appian CCL Investment (UK) Ltd | Financial services | 2024 |
| Appian Omega Bidco Limited | Financial services | 2026 |
| Appian Omega Holdco Limited | Financial services | 2026 |
| Appilar (UK) Limited | Real estate | 2026 |
| Applaa Ltd | Information & communication | 2025 |
| Appleford Technology Limited | Information & communication | 1996 |
| Applemore Studio Designs Limited | Hospitality | 2022 |
| Applerange Limited | Manufacturing | 1985 |