| Aldine Investments Limited | Hospitality | 2012 |
| Alex Dias Photography & Web Limited | Information & communication | 2010 |
| Alexander James Wooden Floors Ltd | Construction | 2021 |
| Alfatroves Ltd | Professional & scientific | 2026 |
| Algocode Ltd | Information & communication | 2016 |
| Alice Care Limited | Professional & scientific | 2025 |
| Align Physiotherapy & Pilates Ltd | Health & social care | 2022 |
| Alion VEG Ltd | Wholesale & retail | 2025 |
| Alison Metcalfe Ltd | Professional & scientific | 2023 |
| ALL in One Stop Tires Limited | Wholesale & retail | 2024 |
| Allbits Solutions Ltd | Construction | 2015 |
| Alleva Limited | Professional & scientific | 2014 |
| Allium Bloom Ltd | Professional & scientific | 2025 |
| Allspark Domestic Services Ltd | Construction | 2016 |
| Allure Brows Limited | Other services | 2023 |
| Allure Skincare LLP | | 2026 |
| Alpen Properties Ltd | Real estate | 2024 |
| Alpha Oak Partners Ltd | Professional & scientific | 2026 |
| Alto London Properties Ltd | Real estate | 2026 |
| AM & IM Services Ltd | Administrative & support | 2022 |
| Amadeus Florist Limited | Wholesale & retail | 2016 |
| Amapiano Brunch Limited | Hospitality | 2021 |
| Ambercroft Construction Limited | Construction | 2019 |
| AMD Renovations Ltd | Real estate | 2022 |
| Amed Buzz Cafe Limited | Hospitality | 2017 |
| Ana's Cleaning Services Ltd | Administrative & support | 2018 |
| Anary Group Limited | Real estate | 2025 |
| ANB Consulting Limited | Professional & scientific | 2009 |
| Anchor Technical Supplies Ltd | Wholesale & retail | 2026 |
| Andersonbaileytravel Limited | Administrative & support | 2020 |
| Andrew Best Digital Limited | Information & communication | 2025 |
| Andromeda Apps Limited | Information & communication | 2024 |
| Andshell LV Ltd | Wholesale & retail | 2026 |
| Andy Marsh Services Limited | Professional & scientific | 2014 |
| Animum Associates Ltd | Professional & scientific | 2023 |
| Anna Rivers Services Ltd | Professional & scientific | 2025 |
| Anthony Miller Limited | Professional & scientific | 2010 |
| Antonios MG Ltd | Other services | 2022 |
| Apex Automobile Wash Limited | Administrative & support | 2026 |
| Apex Cricket UK Ltd | Arts & recreation | 2024 |
| Apple & Oak Home and Conservatory Solutions Limited | Construction | 2020 |
| Appletree Management Company Limited | Households | 1987 |
| Apsley Road Holdings Limited | Real estate | 2021 |
| Aqua DEW LLP | | 2021 |
| Aqua Drops Limited | Real estate | 2017 |
| ARA - Alternative Rope Access Ltd | Other services | 2017 |
| Aramis Security Group UK Ltd | Administrative & support | 2017 |
| Arbk Properties Ltd | Real estate | 2025 |
| Archivehousing Ltd | Real estate | 2026 |
| Ardroe Services Limited | Professional & scientific | 2018 |
| Arian 1 UK Limited | Real estate | 2016 |
| Aries and SON Scaff Ltd | Construction | 2026 |
| Arina Holdings Ltd | Financial services | 2025 |
| ARK Lettings and Management Limited | Real estate | 2015 |
| Arkira Labs Limited | Wholesale & retail | 2024 |
| Arndell House Management Limited | Real estate | 1971 |
| Arnold Scaffolding Ltd | Construction | 2017 |
| ARO Performance Systems Limited | Construction | 1995 |
| Arrowsharpe Limited | Wholesale & retail | 2008 |
| Artesian Homes Ltd | Construction | 2005 |
| Artha Nirvana Ltd | Financial services | 2025 |
| Arthur Alexander Limited | Administrative & support | 1998 |
| ARY Capital Ltd | Construction | 2025 |
| Asad ALI Logistics Limited | Transport & logistics | 2021 |
| Asha J Ltd | Wholesale & retail | 2017 |
| Ashbeen Properties Ltd | Real estate | 2024 |
| Ashinde Limited | Real estate | 2020 |
| Ashsured Tree Experts Ltd | Administrative & support | 2020 |
| Aspire Assets and Investments Ltd | Real estate | 2023 |
| Aspire Assets Group Holdings Ltd | Financial services | 2024 |
| Aspire Properties Investments Ltd | Real estate | 2020 |
| Asset Nominees Limited | Financial services | 1987 |
| Assured Future Consulting Ltd | Professional & scientific | 2025 |
| Astrodyne Limited | Professional & scientific | 2022 |
| Atento Events Limited | Information & communication | 2020 |
| Atft Limited | Wholesale & retail | 2019 |
| Athena Ergane Limited | Professional & scientific | 2026 |
| Athos Security Group Ltd | Administrative & support | 2022 |
| Atlas Real Estates Ltd | Real estate | 2015 |
| Atlas Roofing Construction Limited | Construction | 2017 |
| Ausbrit Ltd | Extraterritorial | 2025 |
| Austin Close Limited | Real estate | 2003 |
| Autism by Experience Community Interest Company | Information & communication | 2006 |
| Autobasil Ltd | Wholesale & retail | 2020 |
| Autolux Motors Ltd | Wholesale & retail | 2024 |
| AVA Concepts Limited | Professional & scientific | 2013 |
| Avani IT Services Ltd | Information & communication | 2019 |
| Avani Property Services Ltd | Real estate | 2025 |
| Avaunt Staking Services Limited | Extraterritorial | 2021 |
| Avoaxemou Ltd | Information & communication | 2025 |
| Awpc Ltd | Professional & scientific | 2024 |
| Axys Business Solutions Limited | Professional & scientific | 2013 |
| AZR Consulting Services Limited | Extraterritorial | 2022 |
| Azure Property Enterprises Ltd | Real estate | 2022 |
| Azure Trading Enterprises Ltd | Wholesale & retail | 2025 |
| B V M Services Limited | Information & communication | 1995 |
| B&E ED Consultancy Ltd | Education | 2025 |
| B&Ok Construction Limited | Construction | 2018 |
| B.Certain! Ltd | Professional & scientific | 2014 |
| B4W Solution Ltd | Construction | 2020 |