| Astrogem Music Limited | Arts & recreation | 2012 |
| Asuse Ltd | Wholesale & retail | 2026 |
| Asvara Ltd | Real estate | 2026 |
| Asyab Ltd | Real estate | 2026 |
| AT Food & Wine Ltd | Wholesale & retail | 2018 |
| AT New Commerce Ltd | Wholesale & retail | 2024 |
| AT Recruitment Ltd | Administrative & support | 2025 |
| Atanas Stanev Ltd | Construction | 2014 |
| Atcom Ltd | Real estate | 2025 |
| Athan Investments Ltd | Real estate | 2021 |
| Athenian Tech Limited | Information & communication | 2022 |
| Athnan Limited | Health & social care | 2008 |
| Atithi Homes Ltd | Real estate | 2024 |
| ATJ Transport Limited | Transport & logistics | 2021 |
| Atkandiah Ltd | Wholesale & retail | 2026 |
| Atlabar Ltd | Construction | 2019 |
| Atlas Automotive Ltd | Wholesale & retail | 2025 |
| Atlas Freight Connect Ltd | Transport & logistics | 2016 |
| ATM Plumbing Solution Ltd | Construction | 2023 |
| Aton Foodies PVT Ltd | Manufacturing | 2026 |
| Atoz Builder Limited | Construction | 2022 |
| Atoz Business Ltd | Other services | 2025 |
| Atozinfo Limited | Information & communication | 2013 |
| ATR Electricals Limited | Construction | 2023 |
| ATR Premium Limited | Wholesale & retail | 2025 |
| Atriahouse Residents Ltd | Information & communication | 2025 |
| Attar Technologies Limited | Information & communication | 2015 |
| Attewell Limited | Manufacturing | 1962 |
| Attire International Limited | Other services | 2020 |
| Attiv Limited | Professional & scientific | 2021 |
| Atwal & Sons Limited | Real estate | 2021 |
| Atwal Holdings Ltd | Financial services | 2025 |
| Atwal Homes Limited | Construction | 2002 |
| AU & AU Holdings Ltd | Financial services | 2021 |
| AU Cloud Limited | Information & communication | 2021 |
| AU Trade Ventures Ltd | Financial services | 2025 |
| AU World Limited | Real estate | 2026 |
| AUA Premier Properties Ltd | Hospitality | 2024 |
| Auditaura Associates Ltd | Administrative & support | 2026 |
| Audlen Limited | Construction | 2021 |
| Audrey's Health Care Limited | Health & social care | 2019 |
| Augustus Aubrey’S Fine Food Ltd | Wholesale & retail | 2025 |
| AUI Holdings Ltd | Real estate | 2022 |
| Aujla Kitchen & Bedroom Ltd | Construction | 2023 |
| Aujla Property Investment Ltd | Real estate | 2020 |
| AUK Hire Ltd | Transport & logistics | 2026 |
| Aura Interior Designs Ltd | Professional & scientific | 2026 |
| Auratrading Ltd | Wholesale & retail | 2024 |
| Aurelian Consultant Ltd | Professional & scientific | 2012 |
| Aureus Homes Ltd | Real estate | 2025 |
| Aurnza Ltd | Wholesale & retail | 2026 |
| Aurora Healthcare Ltd | Public administration | 2023 |
| Aurora Vibes Ltd | Wholesale & retail | 2024 |
| Aurum & Noir Ltd | Wholesale & retail | 2025 |
| Aurum Invest Limited | Real estate | 2015 |
| AUTENTIC76 Limited | Wholesale & retail | 2023 |
| Auto Action Limited | Administrative & support | 2010 |
| Auto Care Center Ltd | Wholesale & retail | 2013 |
| Auto Electrician Hayes Ltd | Wholesale & retail | 2018 |
| Auto Technik CRI Limited | Wholesale & retail | 2012 |
| Automania Garage Services Group Ltd | Financial services | 2026 |
| Automotive Care Parts Limited | Wholesale & retail | 2024 |
| Automotive Corporation Limited | Wholesale & retail | 2018 |
| Autopilothq Ltd | Professional & scientific | 2025 |
| Autopoint London Limited | Wholesale & retail | 2023 |
| Autotronic Ltd | Extraterritorial | 2023 |
| Auxilium Holdings II Limited | Financial services | 2025 |
| AV Compliance Ltd | Information & communication | 2020 |
| AV Construct Ltd | Construction | 2021 |
| AV Construction & Force Ltd | Construction | 2022 |
| AV Construction Limited | Construction | 2014 |
| AV Hair Studio Ltd | Other services | 2026 |
| AV Haulage Ltd | Transport & logistics | 2019 |
| AV Interior Designs Ltd | Professional & scientific | 2025 |
| AV Law Solicitors Limited | Professional & scientific | 2021 |
| AV Production Hire Limited | Hospitality | 2018 |
| AV Property Developers Ltd | Real estate | 2025 |
| AV Roofing Ltd | Construction | 2023 |
| AVA Business Coaching Ltd | Professional & scientific | 2014 |
| AVA Constructions & Decors Ltd | Construction | 2015 |
| AVA Constructions and Project Management Ltd | Construction | 2021 |
| Avalon Trans Ltd | Transport & logistics | 2015 |
| Avana Capital Limited | Information & communication | 2024 |
| Avaneesh Builders Ltd | Construction | 2017 |
| Avanti Chicken Ltd | Hospitality | 2019 |
| Avantus Aerospace Group Limited | Professional & scientific | 2014 |
| Avantus Aerospace Holdco Limited | Professional & scientific | 2014 |
| Avantus Aerospace HOLDCO2 Limited | Professional & scientific | 2014 |
| Avantus Aerospace Limited | Professional & scientific | 2011 |
| Avantus Aerospace Midco Limited | Professional & scientific | 2014 |
| Avara Group Holdings Ltd | Real estate | 2026 |
| Avara Property Management Ltd | Real estate | 2026 |
| AVE Cezar Ltd | Wholesale & retail | 2026 |
| AVE Solution Ltd | Administrative & support | 2013 |
| Aven Broadcast Limited | Information & communication | 2019 |
| Avendra Pearl Restaurant Limited | Hospitality | 2018 |
| Avengers Guarding Ltd | Administrative & support | 2021 |
| Avenly Ltd | Wholesale & retail | 2026 |
| Avestta Ltd | Financial services | 2009 |
| AVI Building Service Ltd | Administrative & support | 2024 |