| Astof Limited | Stockport | 2023 |
| Aston Brookes Investments Limited | Birmingham | 2016 |
| Aston Care Limited | Reading | 2006 |
| Aston Care Services Limited | Bilston | 2023 |
| Aston Chase Psychology Services Ltd | Diss | 2010 |
| Aston Chemists Limited | Accrington | 1987 |
| Aston Children's Care Ltd | London | 2011 |
| Aston Clinic London Limited | New Malden | 2014 |
| Aston Clinic Ltd | London | 2010 |
| Aston Clinton Scientific Limited | Stevenage | 1997 |
| Aston Community Care CIC | Birmingham | 2026 |
| Aston Enterprise UK Limited | Winchester | 2018 |
| Aston Hall Care Limited | Hawarden, Deeside | 2004 |
| Aston Healthcare (Liverpool) Ltd | Bootle | 2022 |
| Aston Healthcare Limited | Bootle | 2001 |
| Aston Hearing Services Limited | London | 2000 |
| Aston House Care Ltd | Hereford | 2020 |
| Aston Pavilion Community Interest Company | Birmingham | 2021 |
| Aston Transitional Care Limited | Wolverhampton | 2014 |
| Aston-Mansfield | London | 1896 |
| Aston-Mansfield Charitable Trust | Manor Park | 1930 |
| Astons Health & Wellbeing Limited | Arundel | 2017 |
| Astonville Consultants Limited | Wilmslow | 2017 |
| Astonwynn Limited | Cardiff | 2014 |
| Astor Care Limited | Oxford | 1989 |
| Astor Hall Limited | Exeter | 2007 |
| Astordia Limited | Craigavon | 2025 |
| Astorex Leisure Limited | Betchworth | 2023 |
| Astori Limited | Haverfordwest | 2025 |
| Astoria Care Ltd | Preston | 2021 |
| Astoria Healthcare Limited | Hounslow | 2011 |
| Astoria Homecare Limited | Brentford | 2016 |
| Astoria Kindergarten and Wraparound Ltd | Bangor | 2025 |
| Astoria Kindergarten Limited | Bangor | 2019 |
| Astounding Care Services Ltd | Reading | 2020 |
| Astounding Skin Aesthetics Ltd | Coventry | 2023 |
| Astra Care Services Limited | Nelson | 2003 |
| Astra Consults Ltd | Lincoln | 2022 |
| Astra Heights Ltd | Lancashire | 2023 |
| Astra Slre Limited | Cardiff | 2026 |
| Astracare (UK) Limited | Clacton On Sea | 2001 |
| Astracare GP Ltd | London | 2025 |
| Astradent (1) Limited | Southampton | 2021 |
| Astradent (2) Limited | Southampton | 2021 |
| Astradent (5) Limited | Salisbury | 2021 |
| Astradent Limited | Southampton | 2020 |
| Astraderm Limited | Wrexham | 2023 |
| Astraea Medical Ltd | Manchester | 2026 |
| Astraea Therapy Services Ltd | Stourbridge | 2020 |
| Astral Lodge Limited | Billericay | 2016 |
| Astral Mandala Foundation Limited | Milton Keynes | 2025 |
| Astralis Care Limited | Birmingham | 2023 |
| Astraluxx Ltd | London | 2026 |
| Astramed Limited | Lytham St Annes | 2024 |
| Astraya Ltd | Nairn | 2013 |
| Astreon Dental Ltd | Eastbourne | 2025 |
| Astrid Group Limited | Walsall | 2013 |
| Astrid Orth Limited | Dumfries | 2012 |
| Astrids Limited | London | 2006 |
| Astrita Limited | Woodstock | 2025 |
| Astrium Partnership Limited | Herne Bay | 2020 |
| Astrixx Limited | Eastleigh | 2021 |
| Astrm Ltd | London | 2025 |
| Astro Healthcare Limited | Newcastle | 2019 |
| Astro Influencer Limited | London | 2022 |
| Astro Meds Ltd | London | 2024 |
| Astrodental P1 Limited | London | 1999 |
| Astroeye Ltd | London | 2025 |
| Astron Health Ltd | Wallington | 2024 |
| Astroteam Health Group Ltd | London | 2025 |
| Astrum House Ltd | Cottingham | 2025 |
| Astute Health Ltd | Harrogate | 2017 |
| Astute Home Care Limited | St Albans | 2020 |
| Astute Orthopaedic Solutions Limited | Newcastle | 2015 |
| Astute Outcomes Limited | Oxford | 2025 |
| Astwood Osteopaths Limited | Redditch | 2005 |
| Asuam Ltd | Romford | 2021 |
| Asubisye Ltd | York | 2015 |
| Asujen Ltd | West Drayton | 2026 |
| Asuk Community CIC | London | 2025 |
| Asuoonline Healthcare Limited | Sheffield | 2016 |
| Asur Body Centre CIC | Dumfries | 2024 |
| Asura Holding Ltd | Bradford | 2016 |
| Asurg Limited | Harpenden | 2025 |
| Asuri and Daughters Limited | Stone | 2014 |
| Asus Care UK Limited | Hemel Hempstead | 2018 |
| Asusian Limited | Frizington | 2025 |
| Asusual Consultants Ltd | Reading | 2015 |
| ASV Healthcare Limited | Preston | 2018 |
| ASW Locum Services Ltd | Caerphilly | 2025 |
| ASW Spinal Experts Ltd | Bury St. Edmunds | 2022 |
| Aswar Anaesthesia Limited | Formby | 2023 |
| ASY Health Ltd | London | 2022 |
| ASY PVT Ltd | Salisbury | 2023 |
| ASY Vision Ltd | Ilford | 2015 |
| ASY7 Ltd | Glasgow | 2021 |
| Asya Medical Services Ltd | Ilford | 2022 |
| Asylum Link Merseyside | Liverpool | 2002 |
| Asyndesis Ltd | Stockport | 2026 |
| Asyra Solutions Limited | London | 2006 |