| Anes Services Limited | Construction | 2026 |
| Anevis Ltd | Construction | 2017 |
| Angel Beauty Parlour Ltd | Other services | 2011 |
| Angel Champagne Limited | Extraterritorial | 2014 |
| Angel Home Care Consultancy Limited | Health & social care | 2016 |
| Angel's Cafe Basildon Ltd | Hospitality | 2023 |
| Angelic Blocks Limited | Real estate | 2026 |
| Angelic Healing With Shahmika Ltd | Other services | 2025 |
| Angelis Enterprise Ltd | Wholesale & retail | 2012 |
| Angels Groups 986 Ltd | Wholesale & retail | 2024 |
| Anglia Consultancy Ltd | Administrative & support | 2024 |
| Anglian Brickwork Limited | Construction | 1995 |
| Anglo Plumbing Ltd | Construction | 2010 |
| Angra Trading Account 3 Ltd | Wholesale & retail | 2016 |
| Angus Accounts Ltd | Professional & scientific | 2024 |
| Angus Renewables Ltd | Construction | 2022 |
| Angus Storage Solutions Ltd | Real estate | 2024 |
| Aniela Services Limited | Other services | 2018 |
| Animated Physiotherapy Ltd | Arts & recreation | 2018 |
| Anirak Construction Ltd | Construction | 2023 |
| Anirey Delights Ltd | Hospitality | 2025 |
| ANJ IT Solutions Ltd | Information & communication | 2011 |
| Ankaiya Ltd | Wholesale & retail | 2025 |
| Anlev (UK) Holdings Limited | Financial services | 2021 |
| Anlev (UK) Limited | Manufacturing | 2020 |
| Anna Imrak Medical Limited | Health & social care | 2013 |
| Annalisa Limited | Health & social care | 2014 |
| Annatex Print Limited | Manufacturing | 2016 |
| Annette Sach Limited | Health & social care | 2018 |
| Annexa Solutions Limited | Wholesale & retail | 2008 |
| Annexcy Limited | Information & communication | 2025 |
| Annie's Attic Southend Ltd | Hospitality | 2018 |
| Anointed Minds Ltd | Construction | 2015 |
| Another Level Scaffolding Limited | Construction | 2013 |
| ANP Pharma Ltd | Wholesale & retail | 2007 |
| ANP Property Investments Limited | Real estate | 2018 |
| Ansi PR Services Limited | Information & communication | 2024 |
| Anstee and Byers Property Development Limited | Construction | 2018 |
| ANT Nails Limited | Other services | 2020 |
| Anthony Charles Transport Limited | Transport & logistics | 2025 |
| Anthony King Solicitors Ltd | Professional & scientific | 2019 |
| Anthony Ndubuisi Ltd | Construction | 2018 |
| Anthonydep Ltd | Health & social care | 2023 |
| Antonio Electrical Ltd | Construction | 2016 |
| Antou Corporation Limited | Professional & scientific | 2010 |
| Anuragfoodstory Ltd | Manufacturing | 2023 |
| Anureddy Limited | Information & communication | 2018 |
| Anvis Furnitures Limited | Wholesale & retail | 2020 |
| ANY Business Solutions Ltd | Professional & scientific | 2024 |
| ANY Help Ltd | Transport & logistics | 2020 |
| ANY Trans Ltd | Transport & logistics | 2020 |
| ANY Waste Management in London Ltd | Water & waste | 2024 |
| Anytask Construction Ltd | Construction | 2024 |
| AOA Accord Care Limited | Health & social care | 2015 |
| AOA Recruitment Ltd | Administrative & support | 2019 |
| AOC Electrical Installations Ltd | Construction | 2012 |
| AOS TM Ltd | Construction | 2021 |
| Aosak UK Ltd | Other services | 2022 |
| AOT Logistics Ltd | Transport & logistics | 2021 |
| AP Recruitment Ltd | Administrative & support | 2025 |
| Apex C&R Developments 1 Ltd | Real estate | 2025 |
| Apex C&R Developments Ltd | Financial services | 2024 |
| Apex Carpentry & Property Maintenance Limited | Construction | 2018 |
| Apex Cladding Ltd | Construction | 2022 |
| Apex Construct Limited | Construction | 2023 |
| Apex Fostering Limited | Health & social care | 2021 |
| Apex Project Consultants Limited | Administrative & support | 2019 |
| Apex Transport Delivery Ltd | Transport & logistics | 2025 |
| Apex Utility Solutions Limited | Other services | 2026 |
| Apex Video Professionals Ltd | Information & communication | 2013 |
| APG Flowers Ltd | Wholesale & retail | 2019 |
| APH 3G Limited | Professional & scientific | 2006 |
| APH4G Limited | Financial services | 2024 |
| APH5G Limited | Financial services | 2024 |
| APL Construction 2016 Ltd | Manufacturing | 2021 |
| APM Estates Ltd | Real estate | 2026 |
| APO Food Limited | Hospitality | 2025 |
| Apogee Ideas Ltd | Administrative & support | 2013 |
| Apollo Bricks Ltd | Real estate | 2023 |
| Apollo CB Consultancy Ltd | Professional & scientific | 2017 |
| Apollo Dental Health Clinic Limited | Health & social care | 2009 |
| Apollo Plant Hire Limited | Manufacturing | 2013 |
| Aponkus Ltd | Construction | 2026 |
| Apos 27 Ltd | Other services | 2023 |
| Appdroidinc Limited | Information & communication | 2017 |
| Apple Flooring Limited | Construction | 2013 |
| Applemed Limited | Professional & scientific | 2010 |
| Appliance Repair Direct Ltd | Other services | 2021 |
| Applied Image Limited | Administrative & support | 2002 |
| Applied Interim Consultants Limited | Professional & scientific | 2015 |
| Apprenticeapex Ltd | Administrative & support | 2025 |
| Approved Code Scheme Board CIC | Other services | 2013 |
| Aqua Green Cleaning and Facilities Ltd | Administrative & support | 2015 |
| Aqua Technology Limited | Professional & scientific | 2023 |
| Aqua Tiles Ltd | Construction | 2018 |
| Aquagenie Water Softeners Limited | Other services | 2026 |
| Aquito Capital Ltd | Construction | 2025 |
| AR Brickwork & Construction Limited | Manufacturing | 2026 |
| Aranova Ltd | Construction | 2021 |
| ARB Group Holdings Limited | Real estate | 2020 |