| Ashwini Ltd | Arts & recreation | 2022 |
| Ashwoods Residents Limited | Households | 1985 |
| ASI Advisory Ltd | Real estate | 2012 |
| Asira Group Ltd | Construction | 2024 |
| ASK Care Homes Ltd | Health & social care | 2022 |
| ASK Events UK Limited | Hospitality | 2023 |
| ASK Hospitality Limited | Hospitality | 2025 |
| ASK Networks Ltd | Professional & scientific | 2017 |
| Askk Consultancy Ltd | Information & communication | 2020 |
| Askk IT Business Solutions Limited | Real estate | 2015 |
| Askomerz LLP | | 2009 |
| Askscrooge.Com Limited | Information & communication | 2003 |
| ASL Executive Ltd | Wholesale & retail | 2011 |
| ASL Restaurant Ltd | Hospitality | 2018 |
| Asmaan Investments Ltd | Real estate | 2023 |
| Asmb Enterprises Limited | Information & communication | 2010 |
| Asmika Capital Limited | Professional & scientific | 2023 |
| ASN Dragusin Ltd | Transport & logistics | 2022 |
| Asolves Property Ltd | Real estate | 2026 |
| ASP Builder Ltd | Construction | 2021 |
| Aspae Properties Ltd | Real estate | 2020 |
| Aspect Pharma Limited | Wholesale & retail | 2010 |
| Aspect Roofing & Building Ltd | Construction | 2026 |
| Aspen Care Limited | Health & social care | 2005 |
| Aspen Cooperation Ltd | Other services | 2019 |
| Aspira Estates Ltd | Real estate | 2023 |
| Aspira Property Group Ltd | Real estate | 2025 |
| Aspire Block and Estate Management Limited | Real estate | 2019 |
| Aspire Desk Ltd | Information & communication | 2022 |
| Aspire Living (SPV) Ltd | Real estate | 2025 |
| Aspire Living Care Ltd | Health & social care | 2025 |
| Aspire Vehicle Services Limited | Wholesale & retail | 2018 |
| Aspirecraft Ltd | Professional & scientific | 2024 |
| ASR Horizon Ltd | Real estate | 2024 |
| Asraa Ltd | Real estate | 2019 |
| Assembleia DE Deus New Life Church Ltd | Other services | 2018 |
| Assertive Leadership Ltd | Professional & scientific | 2026 |
| Asset Academy Ltd | Education | 2019 |
| Asset Emporium Limited | Construction | 2004 |
| Asset Lodge Ltd | Real estate | 2024 |
| Asset Strong Ltd | Real estate | 2005 |
| Assisprac Ltd | Health & social care | 2023 |
| Assist Financial Services Ltd | Professional & scientific | 2022 |
| Assured Acoustics Limited | Professional & scientific | 2016 |
| Assured Building and Landscaping Limited | Administrative & support | 2024 |
| Assured Property Partnership Ltd | Real estate | 2017 |
| Assured Thinking Ltd | Wholesale & retail | 2012 |
| Astariel Ltd | Information & communication | 2026 |
| Astec Construction Ltd | Construction | 2010 |
| Asteraci Limited | Education | 2008 |
| Asterley Clarke Limited | Administrative & support | 1999 |
| Astik Consultancy Ltd | Professional & scientific | 2024 |
| Astikaya Ltd | Information & communication | 2021 |
| Astitch Trading Ltd | Wholesale & retail | 2022 |
| Aston Architectural Aluminium Limited | Manufacturing | 2013 |
| Aston Doors & Windows Ltd | Manufacturing | 2024 |
| Aston Frames Ltd | Manufacturing | 2024 |
| Aston Mullins Bloodstock Limited | Arts & recreation | 2011 |
| Aston Wade Recruitment Limited | Administrative & support | 2015 |
| Astondale Limited | Information & communication | 2015 |
| Astongrove Limited | Real estate | 1976 |
| Astor Contract Interiors Ltd | Construction | 2019 |
| Astral House Limited Partnership | | 2005 |
| Astralux Estate Ltd | Professional & scientific | 2025 |
| Astrastar Limited | Construction | 2000 |
| Astrixa Limited | Information & communication | 2026 |
| Astute Energy Solutions Ltd | Professional & scientific | 2013 |
| Asus Services Ltd | Information & communication | 2018 |
| ASV Holdings Ltd | Other services | 2022 |
| Asvik Enterprises Ltd | Wholesale & retail | 2025 |
| Asvina (UK) Ltd. | Administrative & support | 2009 |
| Asvina Limited | Wholesale & retail | 2012 |
| Asym London Ltd | Transport & logistics | 2026 |
| AT Investment Group Limited | Real estate | 2023 |
| AT the Movies Transport Ltd | Transport & logistics | 2021 |
| At&D Homes Ltd | Real estate | 2024 |
| ATA Private Dining Limited | Hospitality | 2023 |
| Atay (2016) Ltd | Hospitality | 2016 |
| Atech Drains Limited | Administrative & support | 2023 |
| Atelier Joinery Design and Manufacture Limited | Manufacturing | 2017 |
| ATF Interiors Ltd | Manufacturing | 2014 |
| ATH Associates Ltd | Professional & scientific | 2023 |
| Athal Group Limited | Wholesale & retail | 2022 |
| Athena Connection Limited | Other services | 2006 |
| Athena Print Management Limited | Manufacturing | 2018 |
| Athencis Limited | Administrative & support | 2016 |
| Athito Consulting Ltd | Professional & scientific | 2003 |
| Athito London Market Limited | Professional & scientific | 2016 |
| Athlone Homes Limited | Extraterritorial | 2010 |
| Aththnayaka Dance and Wedding Services Ltd | Arts & recreation | 2018 |
| Atiyukt Aroma Ltd | Manufacturing | 2025 |
| Atkins Project Management Ltd | Construction | 2016 |
| Atlan Engineering Ltd | Construction | 2026 |
| Atlantic Solutions Group Limited | Information & communication | 2017 |
| Atlas 1 Holdings Ltd | Financial services | 2026 |
| Atlas 1 Property Services Ltd | Real estate | 2017 |
| Atlee Phoenix Studios Ltd | Information & communication | 2024 |
| Atman Enterprise Limited | Administrative & support | 2012 |
| Atmedia Systems Limited | Information & communication | 2009 |
| Atmosora Events Ltd | Arts & recreation | 2026 |