| Ascend 100 (UK) Limited | Health & social care | 2026 |
| Ascend Management Services Ltd | Administrative & support | 2022 |
| Ascend Technologies Limited | Information & communication | 2013 |
| Ascendium Brands Ltd | Wholesale & retail | 2025 |
| Ascensao Estates Ltd | Real estate | 2022 |
| Ascensia Supported Living Ltd | Health & social care | 2026 |
| Ascentia Lettings and Property Management Limited | Real estate | 2007 |
| Ascofenix Ltd | Information & communication | 2024 |
| Ascot Estate Agents Limited | Real estate | 2013 |
| Ascot Place Management Company Limited | Real estate | 2003 |
| Ascr Technical Ltd | Professional & scientific | 2026 |
| Asdankk Ltd | Transport & logistics | 2024 |
| ASG Landscapes Limited | Professional & scientific | 2024 |
| ASG Payroll Ltd | Professional & scientific | 2023 |
| ASH Bray Limited | Arts & recreation | 2025 |
| ASH Lane Consulting Ltd | Administrative & support | 2017 |
| Asha Bangladeshi Cuisine Ltd | Hospitality | 2013 |
| Ashanti Medical Ltd | Health & social care | 2015 |
| Ashbourne International Ltd | Agriculture & fishing | 2016 |
| Ashbrook House Consulting Limited | Professional & scientific | 2024 |
| Ashbry Limited | Wholesale & retail | 2025 |
| Ashburton Place Residences Limited | Real estate | 2018 |
| Ashbys Pubco Limited | Hospitality | 2021 |
| Ashco Construction Ltd | Construction | 2026 |
| Ashcroft Court Ltd | Administrative & support | 2023 |
| Ashenwood Holdings Limited | Professional & scientific | 1997 |
| Asher Plant Services Limited | Manufacturing | 2013 |
| Ashfield Property Developments (Fordingbridge) Limited | Real estate | 2011 |
| Ashford and Staines Electrical Solutions Ltd | Construction | 2023 |
| Ashgayo Limited | Administrative & support | 2016 |
| Ashie Ventures Limited | Administrative & support | 2020 |
| Ashirah Limited | Other services | 2026 |
| Ashlett Creek Moorings and Preservation Initiative Limited | Transport & logistics | 2026 |
| Ashlett Sailing Club Limited | Arts & recreation | 2010 |
| Ashley & Green Limited | Manufacturing | 2013 |
| Ashley Cleaning Systems Limited | Other services | 2003 |
| Ashley Security Company Limited | Construction | 2001 |
| Ashley's Window Cleaning Ltd | Administrative & support | 2017 |
| Ashleyfork Ltd | Real estate | 2018 |
| Ashtead Aesthetics Skin Clinic Ltd | Health & social care | 2026 |
| Ashurst Build Services Ltd | Construction | 2026 |
| Ashurst Fencing and Gates Limited | Administrative & support | 2021 |
| Ashurst Property Maintenance Limited | Administrative & support | 2015 |
| Ashwood Care Home Ltd | Health & social care | 2014 |
| Ashworth Care Management Company Ltd | Health & social care | 2019 |
| Asia Pacific World Holdings Limited | Professional & scientific | 2020 |
| Asian Cash & Carry Limited | Wholesale & retail | 2000 |
| Asiedu Property Ltd | Real estate | 2024 |
| Asif Estates Ltd | Real estate | 2026 |
| ASJ Clinic Limited | Health & social care | 2024 |
| ASJ Scaffolding Ltd | Construction | 2022 |
| ASK Building Ltd | Construction | 2026 |
| ASK Group Holdings Limited | Real estate | 2024 |
| ASK Group Ltd | Information & communication | 2019 |
| ASK Joan Limited | Information & communication | 2024 |
| ASK Montgomery Academy Limited | Education | 2025 |
| ASK Montgomery Advocates Limited | Professional & scientific | 2022 |
| ASK Montgomery Translators Limited | Professional & scientific | 2025 |
| ASK Plastics Birmingham Ltd | Manufacturing | 2015 |
| ASK Plastics Ltd | Manufacturing | 2015 |
| ASK US Care Limited | Administrative & support | 2020 |
| Askari Security Ltd | Administrative & support | 2015 |
| Askari Security UK Ltd | Administrative & support | 2009 |
| Askc Services Ltd | Construction | 2025 |
| Askham & Syon Lodges Management Company Limited | Households | 1986 |
| Askmargo Ltd | Information & communication | 2025 |
| ASL Southampton Ltd | Hospitality | 2021 |
| Aslan Sound Ltd | Information & communication | 2024 |
| ASM Barbers Ltd | Other services | 2021 |
| ASM Track Ltd | Transport & logistics | 2020 |
| ASN Property Investments Ltd | Real estate | 2025 |
| Aspect Electrical South Ltd | Construction | 2023 |
| Aspect Lifting Solutions Ltd | Construction | 2024 |
| Aspect Projects Southern Limited | Construction | 2015 |
| Aspen House RTM Company Limited | Real estate | 2013 |
| Aspen Resources Limited | Professional & scientific | 1994 |
| Aspin Properties Ltd | Real estate | 2017 |
| Aspin Property Services Ltd | Administrative & support | 2022 |
| Aspire Advisory Limited | Professional & scientific | 2009 |
| Aspire Building and Construction Limited | Construction | 2010 |
| Aspire Community Trust | Education | 2017 |
| Aspire Estate Group Ltd | Real estate | 2025 |
| Aspire Garden Care Limited | Administrative & support | 2015 |
| Aspire Hampshire Ltd | Professional & scientific | 2016 |
| Aspire HE Technologies Limited | Information & communication | 2004 |
| Aspire Removals & Storage Ltd | Transport & logistics | 2021 |
| Aspire Security Group Limited | Administrative & support | 2022 |
| Aspire Southampton Ltd | Real estate | 2007 |
| Aspire Taxis Limited | Transport & logistics | 2025 |
| Asprilla Limited | Wholesale & retail | 2010 |
| Assa Logistics Limited | Transport & logistics | 2025 |
| Assemble Automations Limited | Information & communication | 2025 |
| Assembly Recruitment Ltd | Administrative & support | 2018 |
| Asset Management Financial Advisers Limited | Financial services | 1987 |
| Asset Property Solutions Limited | Real estate | 2024 |
| Asset Recoveries Group Limited | Financial services | 2002 |
| Asset Recoveries UK Limited | Administrative & support | 2002 |
| Asset Space Ltd | Real estate | 2006 |
| ASSET2WEALTH Ltd | Professional & scientific | 2024 |
| Assets Realised Ltd | Administrative & support | 2025 |