| Arul Builders Limited | Construction | 2025 |
| Arun Kanda Properties Limited | Real estate | 2025 |
| ARV Healthcare Ltd | Health & social care | 2024 |
| Arventrax Ltd | Information & communication | 2026 |
| Arvethow Limited | Administrative & support | 2014 |
| Arwu Ltd | Professional & scientific | 2024 |
| ARY Estates Ltd | Real estate | 2020 |
| Arya Builders Ltd | Construction | 2024 |
| Arya Enterprises Global Limited | Real estate | 2023 |
| Arya Enterprises Limited | Real estate | 2017 |
| Arya Jewellery Ltd | Wholesale & retail | 2022 |
| Arya Online Limited | Wholesale & retail | 2023 |
| Aryan Ltd | Hospitality | 2026 |
| Aryan Precision Engineering Ltd | Professional & scientific | 2015 |
| Aryan Transport Ltd | Transport & logistics | 2019 |
| ARZ Trading UK Ltd | Wholesale & retail | 2022 |
| Arzone Limited | Wholesale & retail | 2019 |
| AS & S Property Maintenance Ltd | Construction | 2024 |
| AS Cargo Courier Ltd | Transport & logistics | 2018 |
| AS Citizen Advice Limited | Information & communication | 2023 |
| AS Cyber Associates Limited | Information & communication | 2019 |
| AS Dhami Management Limited | Information & communication | 2025 |
| AS Dhesi Ltd | Transport & logistics | 2025 |
| AS Fashion Limited | Manufacturing | 2000 |
| AS Food Consultancy Limited | Hospitality | 2014 |
| AS Global Shops Limited | Wholesale & retail | 2025 |
| AS Golf Retail Ltd | Wholesale & retail | 2021 |
| AS House of Beauty Ltd | Other services | 2024 |
| AS Key Consultancy Limited | Professional & scientific | 2017 |
| AS Pannu Private Ltd | Hospitality | 2016 |
| AS Property Management Limited | Real estate | 2015 |
| AS PVT Ltd | Transport & logistics | 2019 |
| AS Quinn Property Limited | Real estate | 2020 |
| AS Sadiya Tour & Travels Ltd | Information & communication | 2025 |
| AS Therapeutic Services Limited | Health & social care | 2019 |
| AS Virdee Limited | Health & social care | 2026 |
| AS YOU Were Limited | Financial services | 2017 |
| As&Fj Trader Private Ltd | Wholesale & retail | 2025 |
| As-Sami Ltd | Health & social care | 2023 |
| ASA Driving Academy Ltd | Education | 2023 |
| ASA Empire Ltd | Wholesale & retail | 2026 |
| ASA Group Investments Ltd | Construction | 2018 |
| ASA Logistics Ltd | Transport & logistics | 2016 |
| ASA London Holdings Limited | Financial services | 2015 |
| ASA Physio and Podiatry Service Limited | Health & social care | 2013 |
| ASA Property Consultants Limited | Real estate | 2022 |
| ASA Transport Services Ltd | Transport & logistics | 2016 |
| ASA25 Limited | Health & social care | 2025 |
| Asaa Enterprises Limited | Real estate | 2019 |
| Asaa Healthcare Limited | Health & social care | 2019 |
| Asaad Ltd | Other services | 2019 |
| Asabee Limited | Health & social care | 2016 |
| Asad Law Ltd | Professional & scientific | 2024 |
| ASAM1 Ltd | Transport & logistics | 2025 |
| Asamai Consulting Limited | Professional & scientific | 2010 |
| Asamai Properties Services Ltd | Real estate | 2021 |
| Asante Holdings Ltd | Wholesale & retail | 2015 |
| Asantec Ltd | Administrative & support | 2018 |
| Asapworld Ltd | Wholesale & retail | 2025 |
| Asar Distribution Ltd | Wholesale & retail | 2024 |
| ASB Applications Ltd | Professional & scientific | 2018 |
| ASC Digital Healthtech Ltd | Information & communication | 2025 |
| Ascari Management Limited | Real estate | 2023 |
| Ascend Futures Ltd | Health & social care | 2024 |
| Ascend SME Consulting Limited | Professional & scientific | 2025 |
| Ascend SME Holding Ltd | Financial services | 2026 |
| Ascendi Digital Ltd | Information & communication | 2025 |
| Ascendia Capital Group Limited | Financial services | 2024 |
| Ascending Capital International Ltd | Financial services | 2024 |
| Ascension Consultancy Ltd | Professional & scientific | 2014 |
| Ascent Contracting Ltd | Construction | 2019 |
| Ascentco Catering and Event Management Services Ltd | Hospitality | 2013 |
| Ascentia Medical Limited | Real estate | 2025 |
| Ascl Professional Development Limited | Education | 1990 |
| Asclepius Wellbeing Ltd | Wholesale & retail | 2019 |
| Ascot Garage Co.Limited | Wholesale & retail | 1957 |
| Ascot House 104 Ltd | Financial services | 2018 |
| Ascot Priory Management Company Limited | Households | 2008 |
| Ascott Care Ltd | Administrative & support | 2021 |
| ASD Warehousing & Distribution Ltd | Transport & logistics | 2016 |
| Asdi Ltd | Construction | 2025 |
| Asdor 2 Limited | Transport & logistics | 2005 |
| Asea Enterprises Limited | Wholesale & retail | 2017 |
| Asec City Care Ltd | Health & social care | 2025 |
| Asees Punjabi Sweets Ltd | Manufacturing | 2024 |
| Asega Family Limited | Administrative & support | 2026 |
| Asfam Holdings Limited | Financial services | 2025 |
| ASG Opco Limited | Health & social care | 2025 |
| ASG Propco Limited | Financial services | 2025 |
| Asgara Limited | Wholesale & retail | 2021 |
| ASH ( Loughborough ) Limited | Real estate | 2018 |
| ASH 59 Ltd | Manufacturing | 2017 |
| ASH Driver Services Ltd | Transport & logistics | 2025 |
| ASH Engineering (Leicester) Limited | Professional & scientific | 2018 |
| ASH Estates Limited | Real estate | 2014 |
| ASH Leicester Ltd | Wholesale & retail | 2025 |
| ASH Mason Golf Performance Ltd | Education | 2024 |
| ASH Melts and Scents Ltd | Wholesale & retail | 2025 |
| ASH Recruitment Group Ltd | Administrative & support | 2025 |
| ASH School of Motoring Limited | Education | 2021 |