| ATD Diagnostics Ltd | Belfast | 2026 |
| ATD Fourth World Limited | | 1960 |
| ATD Medical Limited | Aylesbury | 2015 |
| ATD Services Ltd | Burnley | 2024 |
| ATD Surgical Limited | Darwen | 2020 |
| Atdc Limited | Downham Market | 2024 |
| ATE Locuming Ltd | London | 2022 |
| Atebion Futures Ltd | St. Asaph | 2025 |
| Ateef Azam Ltd | Birmingham | 2025 |
| Ateeq Farooq Ltd | Cheadle | 2017 |
| Ategi Limited | Pontypridd | 1994 |
| Ateksha Khanna Limited | London | 2026 |
| Atelier Aesthetics Limited | Wolverhampton | 2025 |
| Atelier Blanc Ltd | Preston | 2025 |
| Atelier Dental Limited | Eastbourne | 2023 |
| Atelierdelesprit Ltd | London | 2021 |
| Atemplonuevo Ltd | Bradford | 2017 |
| Ateri Medicare Ltd | Gravesend | 2022 |
| Aterio Family Support Ltd | Tonbridge | 2021 |
| Atern Senior Care and Support Limited | Gainsborough | 2024 |
| Ateyie Ltd | Bedford | 2026 |
| ATF Bespoke Support Ltd | Bacup | 2019 |
| ATF Unmasked CIC | Accrington | 2025 |
| Atfal Group Ltd | Chadwell Heath | 2025 |
| ATG Crown Limited | Romford | 2019 |
| ATG Group Ltd | London | 2025 |
| ATG Health Ltd | Leeds | 2024 |
| Atgconsultng Limited | Sheffield | 2024 |
| Atgmedical Ltd | Higher Walton | 2025 |
| ATH & Co. Limited | London | 2014 |
| ATH Locum Services Limited | Birmingham | 2003 |
| ATH Medical Services Ltd | Wetherby | 2015 |
| ATH RAD Ltd | Wolverhampton | 2026 |
| Athamos Ltd | Welling | 2021 |
| Athanasia Pathology Limited | London | 2019 |
| Athanasias Medical & Surgical Limited | Scunthorpe | 2017 |
| Athans Dental Ltd | Potters Bar | 2025 |
| Atharv Ltd. | St. Albans | 2016 |
| Athelite Ltd | Sandbach | 2015 |
| Athena & Marie Ltd | Peterborough | 2015 |
| Athena (Teesside) Limited | Tyne & Wear | 2025 |
| Athena A.A. Investments Limited | Harrow | 2019 |
| Athena Aesthetics Skin Care Clinic Limited | Fareham | 2021 |
| Athena Care Group Limited | Swansea | 2013 |
| Athena Care Homes (Arbury) Limited | Basildon | 2023 |
| Athena Care Homes (Bretton) Limited | Basildon | 2016 |
| Athena Care Homes (Chesterton) Limited | Basildon | 2023 |
| Athena Care Homes (Gaywood) Limited | Laindon | 2003 |
| Athena Care Homes (Kings Lynn) Limited | Laindon | 1999 |
| Athena Care Homes (March) Limited | Basildon | 2015 |
| Athena Care Homes (Monmouth) Limited | Laindon | 2018 |
| Athena Case Management Limited | Leicester | 2014 |
| Athena Cheltenham Ltd | Gloucester | 2017 |
| Athena Children's Services Limited | Bedford | 2017 |
| Athena Clinics Ltd | London | 2014 |
| Athena Counselling UK Ltd | London | 2022 |
| Athena Family Services Limited | Bedford | 2020 |
| Athena Hand and Plastic Surgery Ltd | Wilmslow | 2024 |
| Athena Handling Ltd | Nantwich | 2021 |
| Athena Health Consultancy (UK) Limited | Mold | 2015 |
| Athena Health Ltd | Bewdley | 2017 |
| Athena Health Solutions Ltd | Derby | 2025 |
| Athena Health, Well-Being and Performance Solutions CIC | Redditch | 2024 |
| Athena Holistics Limited | Swaffham | 2011 |
| Athena Home Care Limited | Telford | 2023 |
| Athena Housing and Support Limited | Bedford | 2012 |
| Athena Kwok Chinese Medicine and Acupuncture Clinic Limited | London | 2024 |
| Athena Medical Aesthetics Training Limited | Southampton | 2019 |
| Athena Medical and Wellness Ltd | Glasgow | 2024 |
| Athena Neurology Limited | Bristol | 2020 |
| Athena Occupational Health Limited | Derby | 2016 |
| Athena Opco (Albert Road) Limited | Southport | 2023 |
| Athena Opco (Church Road) Limited | Southport | 2023 |
| Athena Opco (New Brighton One) Limited | Southport | 2023 |
| Athena Opco (New Brighton Two) Limited | Southport | 2023 |
| Athena Opco (Ormskirk) Limited | Southport | 2023 |
| Athena Opco (Oxford Road) Limited | Southport | 2023 |
| Athena Opco (Park Road) Limited | Southport | 2023 |
| Athena Opco (SNR) Limited | Southport | 2023 |
| Athena Optical Ltd | Manchester | 2017 |
| Athena Organisation Limited | Birmingham | 2015 |
| Athena Physio Ltd | Walton-On-Thames | 2007 |
| Athena Rescue Limited | London | 2024 |
| Athena Social Work Services Limited | Colchester | 2013 |
| Athena Supported Accommodation (North-East) Limited | Sunderland | 2018 |
| Athena Therapy Services Ltd | Wokingham | 2025 |
| Athena-Hygieia Limited | Harlow | 2024 |
| Athenaeum Proform Ltd | Wellingborough | 2025 |
| Athene Services Limited | West Yorkshire | 2007 |
| Athenian Health Care Ltd | London | 2025 |
| Athens Eyes Limited | Wembley | 2018 |
| Athens Plastic Surgery Ltd | London | 2023 |
| Athepius Ltd | Wigton | 2018 |
| Athera Healthcare Group Limited | London | 2021 |
| Athera Healthcare Limited | London | 2021 |
| Atherapy Limited | Sutton | 2002 |
| Atherapyltd Ltd | London | 2024 |
| Atheriel Imaging Limited | Preston | 2022 |
| Atheris Limited | Leeds | 2025 |
| Atherora Ltd | Preston | 2022 |